Method for producing modified whey protein composition by mild oxidation, modified whey protein composition, and nutritional uses of modified whey protein composition

Abstract

The present invention relates to a method for preparing modified whey protein compositions by mild oxidation under conditions which expose and selectively oxidize the free thiol groups of β-lactoglobulin, and the resulting modified whey protein products have been shown to have superior performance, for example in protein-rich beverage products, and also to have low levels of unpleasant odors, particularly during sterilization heat treatment at neutral pH and during consumption of such beverage products.

Description

[Technical field]

[0001] The present invention relates to a method for preparing modified whey protein compositions by mild oxidation under conditions which expose and selectively oxidize the free thiol groups of β-lactoglobulin, and the resulting modified whey protein products have been shown to have superior performance, for example in protein-rich beverage products, and have also been shown to have low levels of unpleasant odors, particularly during sterilization heat treatment at neutral pH and upon consumption of such beverage products. [Background technology]

[0002] Sterilized, pH-neutral beverages that are rich in whey proteins tend to develop an unpleasant odor during heat treatment, similar to the odor of rotten eggs, and because such beverages are typically bottled shortly after production, the unpleasant odor is apparent to the consumer upon opening the bottle.

[0003] Oxidation of whey protein products, for example with hydrogen peroxide, has previously been used to whiten whey protein products and produce whey protein powders of improved visual quality and microbiologically acceptable quality, but oxidation has also been associated with organoleptic problems, such as the development of unpleasant odors and coloration during storage, due to oxidative degradation of certain components of the whey protein composition.

[0004] Jervis et al. have published a study on the effect of bleaching a high protein whey protein concentrate with hydrogen peroxide or benzoyl peroxide at high temperatures ("Effect of bleaching whey on sensory and functional properties of 80% whey protein concentrate", J. Dairy Sci., 95, pp. 2848-2862, 2012). Sensory analysis of an unheated 10% aqueous solution reconstituted from oxidized whey protein powder showed increased "cardboard odor" and "fatty flavor" and decreased "cooked / milky flavor".

[0005] US Patent Publication No. 20160235082A1 discloses a method for producing a heat-stable whey protein ingredient, which can be produced by subjecting whey protein to a specific heat treatment in the presence of a specific concentration of hydrogen peroxide. Whey protein ingredients, including heat-stable retentates of WPI, WPC or any other form of whey protein ingredient and heat-stable powders of WPI or WPC or any other whey protein powders, can be prepared by heat-treating a whey protein solution mixed with a hydrogen peroxide solution. Heat-stable whey protein has the starting whey protein cystine converted to cystine sulfonic acid, so that the free sulfhydryl groups of the main whey protein, β-lactoglobulin, are converted to compounds such as cysteine ​​sulfonic acid and / or cysteic acid; not only are these suggested to minimize or avoid undesirable gelation, but they are also precursors of the taurine groups of the compounds. Summary of the Invention

[0006] The inventors have discovered that mild oxidation of whey protein products can be used to reduce or even eliminate unpleasant odors, similar to rotten egg odor, that arise during the production of whey protein containing beverages.

[0007] One aspect of the present invention relates to a method for producing an oxidized whey protein composition, the method comprising the steps of: (a) treating a whey protein source to provide a whey protein solution which is subjected to oxidation; wherein the whey protein solution comprises: Contains an oxidizing agent capable of oxidizing the thiol group of cysteine; and The whey protein solution comprises: pH in the range of 6.5 to 9.5, a total protein content of at least 1% w / w based on the weight of the whey protein solution to be oxidized; A beta-lactoglobulin (BLG) content of at least 10% w / w of total protein; a protein content, preferably of at least 30% w / w based on total solids; a total fat content, preferably up to 3% w / w based on total solids; having; and wherein the oxidized whey protein solution further comprises: (i) having a temperature in the range of 0 to 160°C; and / or (ii) pressurized to a pressure in the range of 20 to 4000 bar; (b) incubating the whey protein solution to be oxidized under one or more conditions capable of oxidizing at least a portion of the free thiols of the BLG molecules of the whey protein solution to be oxidized, preferably with the aim of reducing the amount of free thiol groups of the whey protein solution to be oxidized to a maximum of 15 micromoles per gram of protein; wherein the one or more conditions include the following (I) and (II): (I) the whey protein solution to be oxidized has a temperature in the range of 0 to 160°C; and / or (II) pressurizing the whey protein solution to be oxidized to a pressure in the range of 20 to 4000 bar; (c) optionally, and more preferably, subjecting the oxidized whey protein solution or protein concentrate thereof obtained in step (b) to a heat treatment step comprising heating to a temperature of at least 60°C; (d) optionally, and more preferably, drying the protein-containing liquid material derived from at least the oxidized whey protein solution obtained in step (b).

[0008] Another aspect of the present invention relates to an oxidized whey protein composition having: A protein content of at least 30% w / w of total solids; a fat content preferably of maximum 3% w / w based on total solids; Up to 15 micromoles of free thiol groups per gram of protein; a tryptophan content, preferably of at least 0.7% w / w based on total protein; a methionine content preferably of at least 0.3% w / w based on total protein; preferably a kynurenine content of up to 0.2 micrograms per mg of protein; a content of protein-bound sulfur preferably in the range of 100 to 600 micromoles per gram of protein, a content of protein-bound cysteine ​​residues forming disulfide bonds preferably in the range of 150-400 micromoles per gram of protein; a protein weight average molecular weight preferably in the range of 18 kDa to 10,000 kDa, more preferably 50 to 8,000 kDa, and most preferably 80 to 5,000 kDa; having and Preferably, at least 60% w / w, more preferably at least 80% w / w, even more preferably at least 90% w / w, and most preferably at least 99% w / w of the protein has a molecular weight between 18 kDa and 10 000 kDa.

[0009] A further aspect of the present invention relates to a process for producing a food product comprising: processing the oxidized whey protein composition described herein; and / or combining the described oxidized whey protein composition, and / or the treated oxidized whey protein composition, with one or more further ingredients, and optionally treating the combination.

[0010] Preferred examples of food products include heat-treated, and preferably heat-sterilized, beverages having a pH of 5.5 to 8.5.

[0011] Thus, a more specific aspect of the present invention relates to a process for producing a heat-treated, and preferably heat-sterilized, beverage having a pH of 5.5 to 8.5, more preferably a pH of 6.5 to 7.5, comprising the steps of: (1) combining an oxidized whey protein composition as described herein with one or more further ingredients to obtain a liquid mixture having a pH of 5.5 to 8.5, more preferably a pH of 6.5 to 7.5, comprising: a sufficient amount of the oxidized whey protein composition to contribute at least 0.5% w / w protein; and · Water, (2) filling the liquid mixture into a container, preferably a sterile container; and Here, the liquid mixture is heat treated, and preferably heat sterilized, before and / or after filling.

[0012] A further aspect of the present invention relates to the use of an oxidized whey protein composition, preferably an oxidized whey protein composition of the present invention, as a food ingredient, preferably to improve the odour and / or reduce the level of unpleasant odours similar to rotten egg odour in a heat sterilised beverage, preferably having a whey protein content of at least 3% w / w, and having a pH in the range of 5.5 to 8.5, preferably which has been heat sterilised using an indirect heat treatment.

[0013] Yet another aspect of the present invention relates to a food composition comprising: a solid of the oxidized whey protein composition described herein, and one or more further ingredients, preferably selected from: dairy ingredients, preferably non-oxidized dairy ingredients; Plant-derived ingredients, Non-dairy carbohydrate sources, Flavoring agents, and / or · Sweeteners (sweet carbohydrates / polyols / HIS).

[0014] Yet another aspect of the present invention relates to the use of an oxidized whey protein composition, preferably an oxidized whey protein composition of the present invention, as a food ingredient, preferably for improving the odour and / or reducing the level of unpleasant odours similar to rotten egg odour, in a beverage which has been heat sterilised, the beverage having a pH range of 5.5 to 8.5, preferably having a whey protein content of at least 3% w / w, and which has been heat sterilised, preferably using an indirect heat treatment. [Brief description of the drawings]

[0015] [Figure 1] Photographs of beverage samples subjected to simulated UHT processing are shown in Example 2b: Sample 1: WPI-B22 (unheated reference), Sample 2: WPI-B30; Sample 3: WPI-B29; Sample 4: WPI-B28; Sample 5: WPI-B27; Sample 6: WPI-B26; Sample 7: WPI-B25; Sample 8: WPI-B24; Sample 9: WPI-B23. [Diagram 2] Figure 2 shows plots of the amino acid profiles of a non-oxidized WPI reference (WPI-C24), a liquid oxidized WPI according to the invention (WPI-C25), and an oxidized WPI powder according to the invention (WPI-C26). Figure 2 demonstrates that the invention allows for selective oxidation of the free thiols of β-lactoglobulin without compromising the amino acid composition of the whey protein source. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] One aspect of the present invention relates to a method for producing an oxidized whey protein composition, the method comprising the steps of: (a) treating a whey protein source to provide a whey protein solution which is subjected to oxidation; The whey protein solution to be oxidized is Contains an oxidizing agent capable of oxidizing the thiol group of cysteine; and pH in the range of 6.5 to 9.5, a total protein content of at least 1% w / w based on the weight of the whey protein solution to be oxidized; A beta-lactoglobulin (BLG) content of at least 10% w / w of total protein; a protein content, preferably of at least 30% w / w based on total solids; a total fat content, preferably up to 3% w / w based on total solids; having; and wherein the oxidized whey protein solution further comprises: (i) having a temperature in the range of 0 to 160°C; and / or (ii) pressurized to a pressure in the range of 20 to 4000 bar; (b) incubating the whey protein solution to be oxidized under one or more conditions capable of oxidizing at least a portion of the free thiols of the BLG molecules of the whey protein solution to be oxidized, preferably with the aim of reducing the amount of free thiol groups of the whey protein solution to be oxidized to a maximum of 15 micromoles per gram of protein; wherein the one or more conditions include (I) and (II) below: (I) the whey protein solution to be oxidized has a temperature in the range of 0 to 160°C; and / or (II) pressurizing the whey protein solution to be oxidized to a pressure in the range of 20 to 4000 bar; (c) optionally, and more preferably, subjecting the oxidized whey protein solution or protein concentrate thereof obtained in step (b) to a heat treatment step comprising heating to a temperature of at least 60°C; (d) optionally, and more preferably, drying the protein-containing liquid material derived from at least the oxidized whey protein solution obtained in step (b).

[0017] For example, a preferred embodiment of the present invention relates to a method of producing an oxidized whey protein composition, the method comprising: (a) treating a whey protein source to provide a whey protein solution which is subjected to oxidation; The whey protein solution to be oxidized is · Oxidizing agents capable of oxidizing the thiol group of cysteine; and pH in the range of 6.5 to 9.5, a total protein content of at least 1% w / w based on the weight of the whey protein solution to be oxidized; A beta-lactoglobulin (BLG) content of at least 10% w / w of total protein; a protein content, preferably of at least 30% w / w based on total solids; a total fat content, preferably up to 3% w / w based on total solids; having; and wherein the oxidized whey protein solution further comprises: (i) having a temperature in the range of 0 to 65°C; and / or (ii) pressurized to a pressure in the range of 100 to 4000 bar; (b) incubating the whey protein solution to be oxidized under one or more conditions capable of oxidizing at least a portion of the free thiols of the BLG molecules of the whey protein solution to be oxidized, preferably with the aim of reducing the amount of free thiol groups of the whey protein solution to be oxidized to a maximum of 15 micromoles per gram of protein; wherein the one or more conditions include (I) and (II) below: (I) the whey protein solution to be oxidized has a temperature in the range of 0 to 65°C; and / or (II) pressurizing the whey protein solution to be oxidized to a pressure in the range of 100 to 4000 bar; (c) optionally, and more preferably, subjecting the oxidized whey protein solution or protein concentrate thereof obtained in step (b) to a heat treatment step comprising heating to a temperature of at least 60°C; (d) optionally, and more preferably, drying the protein-containing liquid material derived from at least the oxidized whey protein solution obtained in step (b).

[0018] In the context of the present invention, the term "oxidized whey protein composition" relates to a product having a content of free thiol groups of at most 15 micromoles per gram of protein, and most preferably at most 10 micromoles per gram of protein, which is obtainable by the method of the present invention.

[0019] In the context of the present invention, the term "free thiol groups" relates to SH groups, e.g. present in the amino acid cysteine. In whey protein products, the free thiol groups are typically part of the protein and are typically provided by cysteine ​​residues of the protein. In this context, the term "free" means that the SH groups have not reacted with other SH groups to form disulfide bonds (-SS-). The content of free thiol groups is determined according to analysis E.

[0020] In the context of the present invention, the term "total amount of thiol groups" relates to the sum of thiol groups present in the form -SH (i.e. as free thiols) or in the form of disulfide bonds (-SS-). The total amount of thiol groups is determined according to analysis E.

[0021] In the context of the present invention, the term "whey protein solution to be oxidized" relates to an aqueous whey protein solution comprising an oxidizing agent (such as, for example, peroxide) capable of oxidizing the free thiol groups of cysteines.

[0022] In the context of the present invention, the term "β-lactoglobulin" or BLG relates to mammalian species of BLG, e.g., native and / or glycosylated forms, including naturally occurring genetic variants. The term BLG also includes mammalian BLG produced by recombinant microorganisms. The term "BLG" or "β-lactoglobulin" herein excludes denatured and aggregated BLG. The BLG content is measured according to assay L.

[0023] In the context of the present invention, the term "oxidizing agent capable of oxidizing the thiol group of cysteine" refers to one or more oxidizing agents that are characterized by their ability to oxidize the thiol group of cysteine, and thus are capable of oxidizing the free thiol group of BLG when made accessible to the same. Useful examples include, for example, peroxides approved for food production, and most preferably, hydrogen peroxide.

[0024] The term "whey" refers to the liquid phase remaining after precipitation and removal of casein from milk. Precipitation of casein can be achieved, for example, by acidification of the milk and / or by the use of rennet enzymes. There are several types of whey, including "sweet whey", which is a whey product prepared by rennet precipitation of casein, and "acid whey" or "sour whey", which is a whey product prepared by acid precipitation of casein. Acid precipitation of casein can be achieved, for example, by the addition of food acids or by bacterial culture.

[0025] The term "milk serum" refers to the liquid remaining after removal of casein and milk fat globules from milk, for example by microfiltration or large pore ultrafiltration. Milk serum can also refer to "ideal whey".

[0026] In the context of the present invention, the term "whey protein" relates to a protein contained in whey or milk serum. The whey protein may be a subset of the protein species contained in whey or milk serum, a single whey protein species or the complete set of protein species contained in whey and / or milk serum.

[0027] Unfractionated whey proteins typically include α-lactalbumin (ALA), β-lactoglobulin (BLG), bovine serum albumin, immunoglobulins, osteopontin, lactoferrin, and lactoperoxidase. Whey proteins derived from rennet-treated milk further contain casein macropeptide (CMP) in addition to other protein species.

[0028] The analytical methods described herein are used to determine the corresponding parameters relevant to the present invention.

[0029] In some preferred embodiments of the present invention, the oxidizing agent capable of oxidizing a cysteine ​​thiol group comprises or consists of peroxide, ozone, dioxygen, or a combination thereof.

[0030] It is particularly preferred that said oxidizing agent capable of oxidizing cysteine ​​thiol groups comprises or consists of one or more peroxides and oxygen dissolved in the whey protein solution to be oxidized.

[0031] Even more preferably, said oxidizing agent capable of oxidizing cysteine ​​thiol groups comprises or consists of hydrogen peroxide and oxygen dissolved in the whey protein solution to be oxidized.

[0032] In some preferred embodiments of the invention, the oxidizing agent capable of oxidizing a thiol group of cysteine ​​in step (a) comprises peroxide in an amount of at least 50% mol / mol, more preferably at least 70% mol / mol, even more preferably at least 80% mol / mol, and most preferably at least 90% mol / mol, based on the total amount of oxidizing agent capable of oxidizing a thiol group of cysteine.

[0033] An even higher content of peroxide is often preferred, and in some preferred embodiments of the invention, the oxidizing agent capable of oxidizing the thiol group of cysteine ​​in step (a) comprises an amount of peroxide of at least 92% mol / mol relative to the total amount of oxidizing agent capable of oxidizing the thiol group of cysteine, more preferably at least 94% mol / mol, even more preferably at least 96% mol / mol, and most preferably at least 98% mol / mol of peroxide.

[0034] The oxidizing agent capable of oxidizing the thiol group of cysteine ​​often preferably comprises or consists of a peroxide selected from the group consisting of hydrogen peroxide, benzoyl peroxide, peracetic acid, or mixtures thereof.

[0035] It is particularly preferred that said oxidizing agent capable of oxidizing the thiol group of cysteine ​​comprises or consists of hydrogen peroxide.

[0036] In some preferred embodiments of the invention, the oxidizing agent capable of oxidizing a thiol group of cysteine ​​in step (a) comprises hydrogen peroxide in an amount of at least 50% mol / mol, more preferably at least 70% mol / mol, even more preferably at least 80% mol / mol, and most preferably at least 90% mol / mol relative to the total amount of oxidizing agent capable of oxidizing a thiol group of cysteine.

[0037] An even higher content of hydrogen peroxide is often preferred, and in some preferred embodiments of the invention, the oxidizing agent capable of oxidizing a thiol group of cysteine ​​in step (a) comprises hydrogen peroxide in an amount of at least 92% mol / mol, more preferably at least 94% mol / mol, even more preferably at least 96% mol / mol, and most preferably at least 98% mol / mol, based on the total amount of oxidizing agent capable of oxidizing a thiol group of cysteine.

[0038] In some preferred embodiments of the invention, an oxidizing agent capable of oxidizing the thiol group of cysteine ​​is generated enzymatically, for example, by using lactose oxidase or a hexose oxidase (such as glucose oxidase).

[0039] In another preferred embodiment, an oxidizing agent capable of oxidizing the thiol group of cysteine ​​is generated electrochemically.

[0040] There are two main approaches to adding an oxidizing agent capable of oxidizing the thiol groups of cysteine ​​to the whey protein solution to be oxidized in step (a).

[0041] The first approach requires the addition of an oxidizing agent capable of oxidizing the thiol groups of cysteine ​​in step (a) and then at least partially using said oxidizing agent in step (b). This approach is easier to implement, but is often a little more prone to undesired oxidation than the second approach.

[0042] The second approach involves using a relatively low initial content of an oxidizing agent capable of oxidizing the thiol group of cysteine ​​in step (a), but using additional doses (continuous or discontinuous addition) of an oxidizing agent capable of oxidizing the thiol group of cysteine ​​in step (b). The inventors have found that this approach provides a very mild oxidation of the free thiol groups, but it is a little more complicated to carry out than the first approach.

[0043] It is furthermore suitable to carry out the process in which the majority of the oxidizing agent is added in step (a) and a portion of the oxidizing agent is provided in step (b).

[0044] In some preferred embodiments of the invention, a particular utility of the first approach is that: of the whey protein solution to be oxidized in step (a) an oxidizing agent capable of oxidizing the thiol group of cysteine, and Total amount of free thiol groups, is preferably at least 1:2, more preferably at least 1:1, and most preferably at least 2:1.

[0045] of the whey protein solution to be oxidized in step (a) an oxidizing agent capable of oxidizing the thiol group of cysteine; and Total amount of free thiol groups, It is often preferred that the molar ratio between is at least 3:1, more preferably at least 5:1, and most preferably at least 10:1.

[0046] In the context of the present invention, the ratio between the amount of a first component (A) and the amount of a second component (B) means A divided by B, and may also be expressed as A:B.

[0047] In the first approach, preferably of the whey protein solution to be oxidized in step (a) an oxidizing agent capable of oxidizing the thiol group of cysteine; and Total amount of free thiol groups, The molar ratio between is 1:2 to 200:1, more preferably 1:1 to 100:1, even more preferably 2:1 to 30:1, and most preferably 4:1 to 15:1.

[0048] Alternatively and preferably, for the first approach: of the whey protein solution to be oxidized in step (a) an oxidizing agent capable of oxidizing the thiol group of cysteine; and Total amount of free thiol groups, is preferably 1:2 to 15:1, more preferably 1:1.5 to 10:1, even more preferably 1:1 to 8:1, and most preferably 1:1 to 3:1.

[0049] of the whey protein solution to be oxidized in step (a) an oxidizing agent capable of oxidizing the thiol group of cysteine; and Total amount of free thiol groups, It is often preferred that the molar ratio between is 1:2 to 200:1, more preferably 1:1 to 100:1, even more preferably 2:1 to 30:1, and most preferably 4:1 to 15:1.

[0050] Alternatively or preferably, the whey protein solution to be oxidized in step (a) an oxidizing agent capable of oxidizing the thiol group of cysteine; and Total amount of free thiol groups, is preferably 1:2 to 15:1, more preferably 1:1.5 to 10:1, even more preferably 1:1 to 8:1, and most preferably 1:1 to 3:1.

[0051] In some preferred embodiments of the present invention, of the whey protein solution to be oxidized in step (a) an oxidizing agent capable of oxidizing the thiol group of cysteine; and Total amount of free thiol groups, The molar ratio between is 1:1.5 to 15:1, more preferably 1:1.5 to 10:1, even more preferably 1:1.5 to 8:1, and most preferably 1:1.5 to 3:1.

[0052] Even more preferred for the first approach is the following: of the whey protein solution to be oxidized in step (a) an oxidizing agent capable of oxidizing the thiol group of cysteine; and Total amount of free thiol groups, is preferably from 2:1 to 30:1, more preferably from 3:1 to 25:1, even more preferably from 4:1 to 20:1, and most preferably from 5:1 to 15:1.

[0053] In another preferred embodiment of the present invention, of the whey protein solution to be oxidized in step (a) an oxidizing agent capable of oxidizing the thiol group of cysteine; and Total amount of free thiol groups, It is particularly useful for the second approach that the molar ratio between is at most 5:1, more preferably at most 2:1, even more preferably at most 1:1, and most preferably at most 1:2.

[0054] Preferably, and particularly useful for the second approach, of the whey protein solution to be oxidized in step (a) an oxidizing agent capable of oxidizing the thiol group of cysteine; and Total amount of free thiol groups, is preferably at most 1:4, more preferably at most 1:10, even more preferably at most 1:20, and most preferably at most 1:40.

[0055] In the second approach, preferably of the whey protein solution to be oxidized in step (a) an oxidizing agent capable of oxidizing the thiol group of cysteine; and Total amount of free thiol groups, is preferably 1:100 to 5:1, more preferably 1:60 to 2:1, even more preferably 1:40 to 1:1, and most preferably 1:20 to 1:2.

[0056] The pH of the whey protein solution to be oxidized in step (a) is in the range of 6.5 to 9.5.

[0057] In some preferred embodiments of the present invention, the pH of the whey protein solution to be oxidized in step (a) is in the range of 7.0 to 9.5, more preferably 7.1 to 8.5, even more preferably 7.2 to 8.5, and most preferably 7.4 to 8.2. The inventors have found that these pH ranges are particularly beneficial for the rapid and selective oxidation of the free thiol groups of BLG.

[0058] In another preferred embodiment of the present invention, the pH of the whey protein solution to be oxidized in step (a) is in the range of 7.5 to 9.5, more preferably 7.6 to 8.5, even more preferably 7.7 to 8.4, and most preferably 7.7 to 8.3. The inventors have found that these pH ranges are particularly beneficial for the rapid and selective oxidation of the free thiol groups of BLG.

[0059] Alternatively and preferably, the pH of the whey protein solution to be oxidized in step (a) is in the range of 6.5 to 8.5, more preferably 6.6 to 8.0, even more preferably 6.7 to 7.5, and most preferably 6.8 to 7.3.

[0060] The inventors have found that it is beneficial to carry out the process with a protein content of at least 1% w / w, preferably even higher, in order to improve production capacity and reduce the water and energy consumption of the process, particularly where drying is required.

[0061] In some preferred embodiments of the invention, the oxidized whey protein solution of step (a) has a total protein content of at least 2% w / w, more preferably at least 3% w / w, even more preferably at least 5% w / w, and most preferably at least 6% w / w, based on the weight of the oxidized whey protein solution.

[0062] Preferably, the whey protein solution to be oxidized in step (a) has a total protein content in the range of 1-30% w / w, more preferably 3-20% w / w, even more preferably 4-15% w / w, and most preferably at least 6-10% w / w, based on the weight of the whey protein solution to be oxidized.

[0063] The inventors have found that it is often advantageous to keep the protein content below 12% w / w, which presumably limits the level of protein aggregation which occurs in step (b).It is often preferred that the whey protein solution to be oxidized in step (a) has a total protein content in the range of 1-12% w / w, more preferably 3-11% w / w, even more preferably 4-10% w / w, and most preferably at least 5-9% w / w, based on the weight of the whey protein solution to be oxidized.

[0064] In some preferred embodiments of the invention, the oxidized whey protein solution of step (a) has a total protein content of at least 30% w / w based on the total solids of the oxidized whey protein solution, more preferably at least 50% w / w based on the total solids of the oxidized whey protein solution, even more preferably at least 75% w / w, and most preferably at least 85% w / w.

[0065] Preferably, the oxidized whey protein solution of step (a) has a total protein content in the range of 30-99% w / w, based on the total solids of the oxidized whey protein solution, more preferably 50-97% w / w, even more preferably 75-96% w / w, and most preferably at least 85-95% w / w, based on the total solids of the oxidized whey protein solution.

[0066] The whey protein solution to be oxidized in step (a) has a BLG content of at least 10% w / w based on total protein.

[0067] The inventors have found that the whey protein BLG is at least partially responsible for the development of unpleasant odours during heat treatment of food products at neutral pH, and that the free thiol groups of BLG appear to be involved in the development of said odours.The present invention is therefore particularly suitable for the treatment of whey protein sources which contain an amount of BLG, preferably at least 10% w / w BLG relative to total protein.

[0068] In some preferred embodiments of the invention, the oxidized whey protein solution of step (a) has a BLG content of at least 20% w / w relative to the total protein of the oxidized whey protein solution, more preferably at least 40% w / w relative to the total protein of the oxidized whey protein solution, even more preferably at least 45% w / w, and most preferably at least 50% w / w.

[0069] Even more preferably, the oxidized whey protein solution of step (a) may have a BLG content of at least 55% w / w relative to the total protein of the oxidized whey protein solution, more preferably at least 60% w / w, even more preferably at least 80% w / w, and most preferably at least 90% w / w relative to the total protein of the oxidized whey protein solution.

[0070] Preferably, the oxidized whey protein solution of step (a) has a BLG content in the range of 10-99% w / w based on the total protein of the oxidized whey protein solution, more preferably 45-98% w / w, even more preferably 80-96% w / w, and most preferably 90-95% w / w based on the total protein of the oxidized whey protein solution.

[0071] Alternatively and preferably, the whey protein solution to be oxidized in step (a) may have a BLG content in the range of 10 to 90% w / w, based on the total protein of the whey protein solution to be oxidized, more preferably 20 to 80% w / w, even more preferably 30 to 75% w / w, and most preferably 45 to 70% w / w, based on the total protein of the whey protein solution to be oxidized.

[0072] The characteristics and preferences described with respect to the protein composition of the whey protein source apply equally to the protein composition of the whey protein solution to be oxidized in step (a).

[0073] The oxidized whey protein solution of step (a) and the whey protein source from which it is prepared also typically contain at least trace amounts of other whey proteins, for example, the oxidized whey protein solution of step (a) and the whey protein source from which it is prepared also typically contain one or more of alpha-lactalbumin (ALA), caseinomacropeptide (CMP), bovine serum albumin, immunoglobulins, osteopontin, lactoferrin, and lactoperoxidase.

[0074] The oxidized whey protein solution of step (a) and the whey protein source from which it is prepared preferably contain casein in an amount of at most 20% w / w based on total protein, more preferably at most 10% w / w based on total protein, even more preferably at most 6% w / w, and most preferably at most 2% w / w.

[0075] The inventors have discovered that the fat level of the oxidized whey protein solution of step (a) is preferably kept low, preferably below the levels typically contained in whey protein concentrates and high lipid WPIs.

[0076] Preferably, the whey protein solution to be oxidized in step (a) has a total fat content of up to 3% w / w based on total solids.

[0077] Even lower levels of fat are typically preferred, and it is often preferred for the oxidized whey protein solution of step (a) to have a total fat content of at most 1% w / w of total solids, more preferably at most 0.5% w / w of total solids, even more preferably at most 0.2% w / w, and most preferably at most 0.1% w / w.

[0078] The oxidized whey protein solution of step (a) may contain varying amounts of carbohydrates.

[0079] However, it is often preferred that the oxidized whey protein solution of step (a) has a carbohydrate content of up to 65% w / w based on total solids.

[0080] Even lower levels of carbohydrates are typically preferred, and it is often preferred for the oxidized whey protein solution of step (a) to have a carbohydrate content of at most 20% w / w of total solids, more preferably at most 8% w / w of total solids, even more preferably at most 2% w / w, and most preferably at most 0.2% w / w.

[0081] The whey protein solution to be oxidized in step (a) preferably has a degree of protein denaturation of at most 30%, more preferably at most 25%, even more preferably at most 20%, and most preferably at most 15%.

[0082] The degree of protein denaturation is determined according to Example 1.3 of WO2020 / 002426.

[0083] An even lower degree of protein denaturation is often preferred and in some preferred embodiments of the invention the whey protein solution to be oxidized in step (a) preferably has a degree of protein denaturation of at most 12%, more preferably at most 10%, even more preferably at most 8% and most preferably at most 5%.

[0084] The oxidized whey protein solution of step (a) preferably has an ash content of at most 8% w / w based on total solids, more preferably at most 6% w / w, even more preferably at most 5%, and most preferably at most 4.0%.

[0085] In some preferred embodiments of the invention, the whey protein solution to be oxidized in step (a) preferably has an ash content of 0.4-8% w / w based on total solids, more preferably a maximum of 0.5-6% w / w based on total solids, even more preferably 0.5-5% w / w, and most preferably 0.6-4.0% w / w.

[0086] The ash content of the composition is determined according to Example 1.13 of WO2020 / 002426.

[0087] The oxidized whey protein solution of step (a) preferably has a combined magnesium and calcium content of at most 1% w / w based on total solids, more preferably at most 0.7% w / w based on total solids, even more preferably at most 0.5% w / w, and most preferably at most 0.2% w / w.

[0088] In some preferred embodiments of the invention, the whey protein solution to be oxidized in step (a) preferably has a combined magnesium and calcium content of 0.01-1% w / w based on total solids, more preferably a maximum of 0.001-0.7% w / w based on total solids, even more preferably 0.01-0.5% w / w, and most preferably 0.01-0.2% w / w.

[0089] The whey protein solution to be oxidized in step (a) has a solids content of 0.5-50% w / w, more preferably 1-35% w / w, even more preferably 2-20% w / w, and most preferably 3-10% w / w.

[0090] The portion of the oxidized whey protein solution of step (a) that is not constituted by solid matter preferably comprises water. The portion of the oxidized whey protein solution of step (a) that is not constituted by solid matter preferably comprises water in an amount of at least 80% w / w, more preferably at least 90% w / w, even more preferably 95% w / w, and more preferably at least 99% w / w.

[0091] The whey protein solution to be oxidized in step (a) may further comprise: (i) having a temperature in the range of 0 to 160°C; and / or (ii) Pressurized to a pressure in the range of 20 to 4000 bar. This means that the whey protein solution to be oxidized in step (a) has: (i) It must have a temperature in the range of 0 to 160°C; or (ii) It needs to be pressurized to a pressure in the range of 20 to 4000 bar; or (i+ii) It must have a temperature in the range of 0 to 160°C and be pressurized to a pressure in the range of 20 to 4000 bar; This means that...

[0092] In some preferred embodiments of the invention, step (a) includes condition (i).

[0093] In another preferred embodiment of the invention, step (a) comprises condition (ii).

[0094] In a further preferred embodiment of the invention, step (a) comprises both features (i) and (ii).

[0095] The inventors have discovered that it is suitable to practice the invention using both the temperature range (i) and the pressure range (ii) simultaneously, and that under the conditions described herein, both increased temperature and increased pressure favor the selective oxidation of the free thiol of BLG.

[0096] Preferably, condition (i) of step (a) comprises the oxidizing whey protein solution having a temperature in the range of 5 to 65°C, more preferably 10 to 65°C, even more preferably 30 to 60°C, and most preferably 40 to 55°C.

[0097] The inventors have discovered that the lowest pH range, close to pH 6.5, requires higher temperatures to obtain efficient oxidation compared to the higher pH ranges.

[0098] In some embodiments of the present invention, the pH of the whey protein solution to be oxidized in step (a) is in the range of 6.5 to 7.0 and its temperature is in the range of 40 to 65°C, more preferably 45 to 65°C, even more preferably 50 to 65°C, and most preferably 55 to 65°C.

[0099] In some preferred embodiments of the present invention, the whey protein solution to be oxidized in step (a) has a pH in the range of 7.1 to 9.5 and a temperature in the range of 5 to 65°C, more preferably 10 to 65°C, even more preferably 30 to 60°C, and most preferably 40 to 55°C.

[0100] In another preferred embodiment of the present invention, the whey protein solution to be oxidized in step (a) has a pH in the range of 8.5 to 9.5 and a temperature in the range of 0 to 65°C, more preferably 0 to 50°C, even more preferably 0 to 30°C, and most preferably 5 to 25°C.

[0101] The inventors have found that it is particularly preferred that the whey protein solution to be oxidized in step (a) has a pH in the range of 7.5-8.5 and a temperature in the range of 5-60° C., more preferably 10-60° C., even more preferably 15-60° C., and most preferably 20-60° C. These ranges appear to be favourable for both selective oxidation of the free thiols of BLG and for a relatively fast reaction rate.

[0102] Furthermore, the inventors have found that it is particularly preferred that the whey protein solution to be oxidized in step (a) has a pH in the range of 7.7 to 8.5 and a temperature in the range of 25 to 55° C., more preferably 30 to 55° C., even more preferably 35 to 50° C., and most preferably 35 to 45° C. These ranges also appear to be favorable for both the selective oxidation of the free thiols of BLG and for the relatively fast reaction rate.

[0103] The inventors have found that it may be advantageous from a production perspective if the whey protein solution to be oxidized in step (a) has a pH in the range of 6.8 to 7.5, thereby reducing the need for pH adjustment after oxidation.

[0104] The inventors have found that even higher temperatures can be used in step (a) and in some preferred embodiments of the invention, condition (i) comprises the oxidized whey protein solution of step (a) having a temperature in the range of 66-160°C, more preferably 70-145°C, even more preferably 75-120°C, and most preferably 80-100°C.

[0105] Furthermore, the inventors have found that it is particularly preferred that the pH of the whey protein solution to be oxidized in step (a) is in the range of 7.5-8.5, more preferably 7.7-8.5, and that the temperature is in the range of 66-160° C., more preferably 70-145° C., even more preferably 75-120° C., and most preferably 80-100° C. These ranges also appear to be favorable for both the selective oxidation of the free thiols of BLG and for the relatively fast reaction rate. As can be seen from Example 16, these combinations allow for a very fast step (b) and an oxidation process that is completed in a matter of minutes or less.

[0106] When condition (i) is used in step (a), the pressure of the whey protein solution to be oxidized is typically less than 100 bar, and typically in the range of 0.1 to 100 bar, and more preferably in the range of 1 to 80 bar.

[0107] Pressures of 100 bar or more may be used by combining condition (i) with condition (ii) in step (a).

[0108] Preferably, condition (ii) of step (a) comprises pressurising the whey protein solution to be oxidised in step (a) to a pressure in the range of from 20 to 4000 bar, more preferably from 200 to 3500 bar, even more preferably from 300 to 3000 bar, and most preferably from 500 to 2500 bar.

[0109] In some preferred embodiments of the present invention, condition (ii) of step (a) comprises pressurizing the whey protein solution to be oxidized in step (a) to a pressure in the range of 100 to 1000 bar, more preferably 150 to 800 bar, even more preferably 200 to 600 bar, and most preferably 200 to 500 bar.

[0110] In another preferred embodiment of the invention, condition (ii) comprises the whey protein solution to be oxidized in step (a) being pressurized to a pressure in the range of from 25 to 1000 bar, more preferably from 30 to 500 bar, even more preferably from 35 to 300 bar, and most preferably from 40 to 200 bar.

[0111] When condition (ii) is used in step (a), the temperature is typically in the range and under conditions of 0 to 65° C., more preferably 5 to 65° C., even more preferably 20 to 60° C., and most preferably 40 to 60° C. Thus, condition (ii) is preferably used together with condition (i), although condition (i) may be used without condition (ii).

[0112] The inventors have found that when step (a) also includes condition (ii), a lower temperature is often sufficient. In some preferred embodiments of the present invention, step (a) includes the use of condition (ii), and the whey protein solution to be oxidized in step (a) has a temperature in the range of 0-50°C, more preferably 0-40°C, even more preferably 0-30°C, and most preferably 2-20°C.

[0113] However, when condition (ii) is used in step (a), the temperature may be in the range of 66-160°C, more preferably 70-145°C, even more preferably 75-120°C, and most preferably 80-100°C.

[0114] The treatment of the whey protein source in step (a) typically involves one or more treatment steps in which the whey protein source is contacted with an oxidizing agent capable of oxidizing cysteine ​​thiols and adjusting the protein content, pH, and temperature and / or pressure to the desired levels.

[0115] Preferably, the treatment of the whey protein source in step (a) comprises at least (I) and (II), and optionally (III), and / or (IV) of the following: (I) contacting, preferably by combining or mixing, the whey protein source with at least one oxidizing agent capable of oxidizing cysteine ​​thiols, and optionally with further components (e.g., water); (II) adjusting the pH, if necessary, to a desired pH range (e.g., a pH range of 6.5 to 9.5); (III) optionally pressurizing to a desired pressure range (e.g., a pressure range of 20-4000 bar, such as 100-4000 bar or 20-200 bar); (IV) Optionally, adjusting the temperature to a desired temperature range, for example, a temperature in the range of 0 to 160°C (e.g., 0 to 65°C or 66 to 160°C, etc.).

[0116] It is often preferable to keep the oxidized whey protein solution in liquid form and, if the temperature of the oxidized whey protein solution exceeds, for example, 100° C., to pressurize the solution to avoid boiling and evaporation.

[0117] In step (a), the order of the process steps (I), (II), (III) and (IV) is not critical, so long as an oxidized whey protein solution having the desired properties is obtained.

[0118] The pH adjustment in process step (II) is preferably carried out before or during process step (I). Alternatively, the pH adjustment in process step (II) may be carried out after process step (I). However, in step (a), it is often preferable to minimize the contact time of the whey protein source with the oxidizing agent if the pH and temperature and / or pressure are outside the desired ranges.

[0119] Process step (III) is preferably carried out after process step (I).

[0120] Process step (IV) is preferably carried out before, during or after process step (I).

[0121] Preferably, the whey protein source and the intermediate mixture comprising the whey protein source in step (a) has a temperature not higher than 65°C, and most preferably not higher than 55°C.

[0122] In the context of the present invention, the term "whey protein source" relates to a whey protein composition used in the preparation of the oxidized whey protein solution in step (a). The whey protein source may be a single whey protein composition, e.g. a whey protein powder or an aqueous whey protein liquid, or the whey protein source may be a combination of multiple secondary sources, e.g. multiple whey protein powders and / or multiple aqueous whey protein liquids. When multiple secondary sources are used, they may be combined to form a single composition prior to the preparation of the oxidized whey protein solution in step (a) or may be added individually during the preparation of the oxidized whey protein solution in step (a). When multiple secondary sources are used, the term "whey protein source" characterizes the combination of secondary sources used.

[0123] The whey protein source may be a powder or a liquid. If provided in powder form, it is preferred to reconstitute the whey protein source powder with water and allow it to hydrate for at least 0.5 hours before further processing takes place.

[0124] The whey protein source is preferably a whey protein concentrate (WPC), a whey protein isolate (WPI), or a combination thereof.

[0125] In the context of the present invention, the term "whey protein concentrate" (WPC) relates to a dry or aqueous composition comprising a total amount of protein of 20-89% w / w based on the total solids.

[0126] The WPC preferably comprises: 30-85% w / w protein based on total solids. BLG, 15-90% w / w of total protein; ALA at 4-50% w / w of total protein; and CMP of 0-40% w / w relative to protein.

[0127] Most preferably, the WPC comprises: 70-85% w / w protein based on total solids; BLG, 30-90% w / w of total protein; ALA at 4-35% w / w of total protein; and CMP of 0-25% w / w on protein.

[0128] Whey protein WPCs typically contain no or only traces of CMP.

[0129] The term "whey protein isolate" (WPI) relates to a dry or aqueous composition containing a total amount of protein of 86-100% w / w relative to the total solids.

[0130] The WPI preferably comprises: 86-99% w / w protein on total solids; BLG, 30-100% w / w of total protein; ALA at 0-35% w / w of total protein; and CMP of 0-25% w / w of total protein.

[0131] Most preferably, the WPI comprises: 90-99% w / w protein on total solids; BLG, 50-99% w / w of total protein; ALA at 0-35% w / w of total protein; and CMP of 0-25% w / w of total protein.

[0132] Whey protein WPIs typically contain no or only trace amounts of CMP.

[0133] It is particularly preferred that the whey protein source is a WPI.

[0134] The characteristics and preferences described with respect to the protein, fat, carbohydrate and mineral composition of the oxidized whey protein solution of step (a) apply equally to the whey protein source.

[0135] The whey protein source preferably has a degree of protein denaturation of at most 30%, more preferably at most 25%, even more preferably at most 20% and most preferably at most 15%.

[0136] Even lower degrees of protein denaturation are often preferred, and in some preferred embodiments of the invention the whey protein source has a degree of protein denaturation of at most 12%, more preferably at most 10%, even more preferably at most 8% and most preferably at most 5%.

[0137] In step (b), the whey protein solution to be oxidized is incubated under one or more conditions capable of oxidizing free thiols on at least a portion of the BLG molecules of the whey protein solution to be oxidized.

[0138] "One or more conditions" means particular temperature conditions and / or particular pressure conditions.

[0139] The inventors have discovered that, provided that the method includes a heat treatment in step (c) and that the oxidized thiol groups react with the non-oxidized free thiol groups in step (c) to form stable intermolecular disulfide bonds, oxidation of only some of the free thiol groups, referred to herein as "partial oxidation," may be sufficient.

[0140] In some preferred embodiments of the invention, step (b) is carried out such that the initial amount of free thiol groups in the oxidized whey protein solution of step (a) is reduced or decreased by at most 80% of the initial amount, more preferably at most 76% of the initial amount, even more preferably at most 73%, and most preferably at most 70%.

[0141] In some preferred embodiments of the invention, step (b) reduces or is carried out such that the initial amount of free thiol groups in the oxidized whey protein solution of step (a) is reduced to 20-80% of the initial amount, more preferably 30-80%, even more preferably 50-75%, and most preferably 60-75% of the initial amount, these ranges are often preferred when the method also includes step (c).

[0142] In some preferred embodiments of the present invention, whether or not step (c) is included, step (b) is carried out such that the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a) is reduced or decreased by at most 30% of the initial amount, more preferably at most 25% of the initial amount, even more preferably at most 20% and most preferably at most 15%.

[0143] Preferably, whether or not step (c) is included, step (b) is carried out such that the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a) is reduced or decreased to a maximum of 10% of the initial amount, more preferably to a maximum of 5% of the initial amount, even more preferably to a maximum of 3%, and most preferably to a maximum of 1%.

[0144] A small residual amount of free thiols is often tolerable and may even be desirable to avoid unnecessary oxidative damage to other components of the whey protein solution. Preferably, step (b) is carried out to reduce or reduce the initial amount of free thiols in the whey protein solution to be oxidized in step (a) to 0.01-30% of the initial amount, more preferably 0.02-25%, even more preferably 0.05-20%, and most preferably 0.1-10% of the initial amount.

[0145] In some preferred embodiments of the invention, step (b) is carried out to, or for a time sufficient to, reduce the amount of free thiol in the oxidized whey protein solution to at most 15 micromoles per gram of protein, more preferably at most 14 micromoles per gram of protein, even more preferably at most 13 micromoles per gram of protein, and most preferably at most 12 micromoles per gram of protein.

[0146] Preferably, step (b) is carried out to reduce, or for a time sufficient to reduce, the amount of free thiol in the whey protein solution to be oxidized to 0.001 to 15 micromoles per gram of protein, more preferably 0.01 to 14 micromoles per gram of protein, even more preferably 0.01 to 13 micromoles per gram of protein, and most preferably 0.01 to 12 micromoles per gram of protein.

[0147] Lower levels are often preferred and in some preferred embodiments of the invention, step (b) is carried out to, or for a time sufficient to, reduce the amount of free thiol in the whey protein solution to be oxidized to at most 10 micromoles per gram of protein, more preferably at most 8 micromoles per gram of protein, more preferably at most 5 micromoles per gram of protein, even more preferably at most 3 micromoles per gram of protein, and most preferably at most 2 micromoles per gram of protein.

[0148] Preferably, step (b) is carried out to reduce, or for a time sufficient to reduce, the amount of free thiol in the whey protein solution to be oxidized to 0.001 to 10 micromoles, more preferably 0.01 to 8 micromoles per gram of protein, more preferably 0.01 to 5 micromoles per gram of protein, even more preferably 0.01 to 3 micromoles per gram of protein, and most preferably 0.01 to 2 micromoles per gram of protein.

[0149] Even lower levels of free thiol groups may be desired and in some preferred embodiments of the invention, step (b) is carried out for a time sufficient to reduce, or to reduce, the amount of free thiol in the oxidized whey protein solution to at most 1 micromole per gram of protein, more preferably at most 0.7 micromole per gram of protein, even more preferably at most 0.5 micromole per gram of protein, and most preferably at most 0.2 micromole per gram of protein.

[0150] The inventors have observed that the oxidation of step (b) causes a slight decrease in pH of the whey protein solution and have found that it is often advantageous to adjust the pH of step (b) to keep it in the desired pH range, especially at higher ratios between oxidizing agent and thiol groups.

[0151] In some preferred embodiments of the present invention, step (b) comprises adjusting the pH during oxidation to a pH in the range of 6.5 to 9.5, more preferably 7.0 to 8.5, even more preferably 7.2 to 8.5, and most preferably 7.5 to 8.5.

[0152] The inventors have discovered that carrying out the oxidation at a pH in the range of 7.0-8.5, even more preferably 7.2-8.5, and most preferably 7.5-8.5, results in selective oxidation of free thiol groups relative to other oxidation targets (e.g. methionine and tryptophan) within the whey protein solution.

[0153] Preferably, step (b) comprises adjusting the pH during the oxidation to a range of from 7.5 to 9.5, more preferably from 7.6 to 8.5, even more preferably from 7.7 to 8.4, and most preferably from 7.7 to 8.3.

[0154] The pH adjustment in step (b) may, for example, involve one or more discrete pH adjustments, or more preferably, continuous pH control, for example using a pH stat, preferably using one or more food acceptable acids and / or bases.

[0155] In particular, the inventors have found that it is beneficial to limit the amount of oxidant consumed in step (b) in order to avoid undesirable oxidation reactions.

[0156] In some preferred embodiments of the present invention: the amount of oxidizing agent capable of oxidizing the thiol group of cysteine ​​consumed in step (b) (excluding the amount of excess oxidizing agent removed in the final step of step (b)); and the initial amount of free thiol groups in step (a), is preferably 1:2 to 30:1, more preferably 1:2 to 25:1, even more preferably 1:2 to 20:1, and most preferably 1:1 to 15:1.

[0157] Also, the amount of oxidizing agent capable of oxidizing the thiol group of cysteine ​​consumed in step (b) (excluding the amount of excess oxidizing agent removed in the final step of step (b)); and the initial amount of free thiol groups in step (a), It is often preferred that the molar ratio between is from 2:1 to 30:1, more preferably from 3:1 to 25:1, even more preferably from 4:1 to 20:1, and most preferably from 5:1 to 15:1.

[0158] Surprisingly, the inventors have found that the partial oxidation of free thiol groups in combination with the heat treatment of step (c) also results in an oxidized whey protein composition having a very low content of free thiol groups. Thus, in some preferred embodiments of the present invention: the amount of oxidizing agent capable of oxidizing the thiol group of cysteine ​​consumed in step (b) (excluding the amount of excess oxidizing agent removed in the final step of step (b)); and the initial amount of free thiol groups in step (a), is preferably 1:4 to 15:1, more preferably 1:3 to 10:1, even more preferably 1:2 to 5:1, and most preferably 1:2 to 2:1.

[0159] Preferably, step (b), and the process of the invention itself, does not involve the addition of sulfites and does not involve sulfitolysis.

[0160] In some preferred embodiments of the invention, the one or more conditions in step (b) include (I) the oxidizing whey protein solution having a temperature in the range of 5 to 65°C, more preferably 10 to 65°C, even more preferably 30 to 60°C, and most preferably 40 to 60°C.

[0161] The temperature range of the oxidized whey protein solution in step (b) is preferably the same as the temperature range of the oxidized whey protein solution in step (a), however, the inventors have also found that it may be beneficial to increase the temperature in step (b), for example when step (a) is at a relatively low temperature, and that step (b) may comprise different temperature stages.

[0162] The inventors have discovered that the lowest pH range, close to pH 6.5, requires higher temperatures for efficient oxidation compared to the higher pH ranges.

[0163] In some embodiments of the present invention, the pH of the whey protein solution to be oxidized in step (b) is in the range of 6.5 to 7.0 and its temperature is in the range of 40 to 65°C, more preferably 45 to 65°C, even more preferably 50 to 65°C, and most preferably 55 to 65°C.

[0164] In some preferred embodiments of the present invention, the pH of the whey protein solution to be oxidized in step (b) is in the range of 7.1 to 9.5 and its temperature is in the range of 5 to 65°C, more preferably 10 to 65°C, even more preferably 30 to 60°C, and most preferably 40 to 55°C.

[0165] In another preferred embodiment of the present invention, the pH of the whey protein solution to be oxidized in step (b) is in the range of 8.5 to 9.5, and its temperature is in the range of 0 to 65°C, more preferably 0 to 50°C, even more preferably 0 to 30°C, and most preferably 5 to 25°C.

[0166] The inventors have found that it is particularly preferred that the pH of the whey protein solution to be oxidized in step (b) is in the range of 7.5 to 8.5 and that its temperature is in the range of 5 to 60° C., more preferably 10 to 60° C., even more preferably 15 to 60° C., and most preferably 20 to 60° C. These ranges are believed to be favorable for both selective oxidation of the free thiols of BLG and for a relatively fast reaction rate.

[0167] Furthermore, the inventors have found that it is particularly preferred that the pH of the whey protein solution to be oxidized in step (b) is in the range of 7.7 to 8.5 and that its temperature is in the range of 25 to 55° C., more preferably 30 to 55° C., even more preferably 35 to 50° C., and most preferably 35 to 45° C. These ranges also appear to be favorable for both the selective oxidation of the free thiols of BLG and for the relatively fast rate of reaction.

[0168] The inventors have found that higher temperatures can also be used in step (b), and in some preferred embodiments of the invention, condition (I) comprises the oxidized whey protein solution of step (b) having a temperature in the range of 66-160°C, more preferably 70-145°C, even more preferably 75-120°C, and most preferably 80-100°C.

[0169] Furthermore, the inventors have found that it is particularly preferred that the pH of the whey protein solution to be oxidized in step (b) is in the range of 7.5-8.5, more preferably 7.7-8.5, and that the temperature is in the range of 66-160° C., more preferably 70-145° C., even more preferably 75-120° C., and most preferably 80-100° C. These ranges also appear to be favorable for both the selective oxidation of the free thiols of BLG and for the relatively fast reaction rate. As can be seen from Example 16, these combinations allow for a very fast step (b) and an oxidation process that is completed in a time of a few minutes or less.

[0170] The inventors have found that it may be advantageous from a production perspective if the whey protein solution to be oxidized in step (b) has a pH in the range of 6.8 to 7.5, which reduces the need for pH adjustment after oxidation.

[0171] In some preferred embodiments of the present invention, the temperature of the whey protein solution to be oxidized in step (b) is maintained within a desired temperature range for a time sufficient to reduce the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a) to at most 80% of the initial amount, more preferably at most 76% of the initial amount, even more preferably at most 73%, and most preferably at most 70%.

[0172] As mentioned above, partial oxidation of free thiol groups may be beneficial by involving a heat treatment in step (c), and in some preferred embodiments of the present invention, the temperature of the whey protein solution to be oxidized in step (b) is maintained within a desired temperature range for a time sufficient to reduce the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a) to 20-80% of the initial amount, more preferably 30-80%, even more preferably 50-75%, and most preferably 60-75% of the initial amount.

[0173] Preferably, the temperature of the whey protein solution to be oxidized in step (b) is maintained within the desired temperature range for a time sufficient to reduce the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a) to at most 30% of the initial amount, more preferably at most 25% of the initial amount, even more preferably at most 20%, and most preferably at most 15%.

[0174] Preferably, in step (b), the temperature is maintained within the desired temperature range for a time sufficient to reduce the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a) to a maximum of 10% of the initial amount, more preferably to a maximum of 5% of the initial amount, even more preferably to a maximum of 3%, and most preferably to a maximum of 1%.

[0175] Preferably, in step (b), the temperature is maintained within the desired temperature range for a time sufficient to reduce the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a) to 0.01-30% of the initial amount, more preferably 0.02-25%, even more preferably 0.05-20%, and most preferably 0.1-10% of the initial amount.

[0176] Preferably, the temperature of the oxidized whey protein solution in step (b) is maintained within the desired temperature range for a time sufficient to reduce the amount of free thiol in the oxidized whey protein solution to at most 15 micromoles per gram of protein, more preferably at most 14 micromoles per gram of protein, even more preferably at most 13 micromoles per gram of protein, and most preferably at most 12 micromoles per gram of protein.

[0177] The temperature of the whey protein solution to be oxidized in step (b) is often maintained within a desired temperature range for a time sufficient to reduce the amount of free thiol in the whey protein solution to between 0.001 and 15 micromoles per gram of protein, more preferably between 0.01 and 14 micromoles per gram of protein, even more preferably between 0.01 and 13 micromoles per gram of protein, and most preferably between 0.01 and 12 micromoles per gram of protein.

[0178] Preferably, the temperature of the oxidized whey protein solution in step (b) is maintained within the desired temperature range for a time sufficient to reduce the amount of free thiol in the oxidized whey protein solution to at most 10 micromoles per gram protein, more preferably at most 8 micromoles per gram protein, more preferably at most 5 micromoles per gram protein, even more preferably at most 3 micromoles per gram protein, and most preferably at most 2 micromoles per gram protein.

[0179] Preferably, step (b) is maintained at the desired temperature range for a time sufficient to reduce the amount of free thiol in the whey protein solution to be oxidized to 0.001 to 10 micromoles per gram of protein, more preferably 0.01 to 8 micromoles per gram of protein, more preferably 0.01 to 5 micromoles per gram of protein, even more preferably 0.01 to 3 micromoles per gram of protein, and most preferably 0.01 to 2 micromoles per gram of protein.

[0180] Even lower levels of free thiol groups may be desired and in some preferred embodiments of the invention the temperature of the oxidized whey protein solution in step (b) is maintained within the desired temperature range for a time sufficient to reduce the amount of free thiol in the oxidized whey protein solution to at most 1 micromole per gram of protein, more preferably at most 0.7 micromole per gram of protein, even more preferably at most 0.5 micromole per gram of protein, and most preferably at most 0.2 micromole per gram of protein.

[0181] When condition (I) is used in step (b), the pressure of the whey protein solution to be oxidized is typically less than 100 bar, and typically in the range of 0.1 to 100 bar, and more preferably in the range of 1 to 80 bar.

[0182] Pressures of 100 bar or more may be used by combining condition (I) with condition (II) in step (b).

[0183] In another preferred embodiment of the present invention, step (b) comprises condition (II), wherein the whey protein solution to be oxidized is pressurized to a pressure in the range of 20-4000 bar, more preferably 200-3500 bar, even more preferably 300-3000 bar, and most preferably 500-2500 bar.

[0184] However, in a further preferred embodiment of the invention, condition (II) comprises the whey protein solution to be oxidized being pressurized to a pressure in the range of from 20 to 500 bar, more preferably from 30 to 300 bar, and most preferably from 40 to 200 bar.

[0185] The pressure range of the whey protein solution to be oxidized in step (b) is preferably the same as the pressure range of the whey protein solution to be oxidized in step (a).

[0186] In some preferred embodiments of the present invention, the pressure of the whey protein solution to be oxidized in step (b) is maintained within a desired pressure range for a time sufficient to reduce the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a) to at most 80% of the initial amount, more preferably at most 76% of the initial amount, even more preferably at most 73%, and most preferably at most 70%.

[0187] As mentioned above, partial oxidation of free thiol groups may be beneficial by accompanying heat treatment in step (c), and in some preferred embodiments of the present invention, the pressure of the whey protein solution to be oxidized in step (b) is maintained within a desired pressure range for a time sufficient to reduce the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a) to 20-80% of the initial amount, more preferably 30-80%, even more preferably 50-75%, and most preferably 60-75% of the initial amount.

[0188] Preferably, pressure is applied to the whey protein solution to be oxidized in step (b) for a time sufficient to reduce the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a) to at most 30% of the initial amount, more preferably at most 25% of the initial amount, even more preferably at most 20%, and most preferably at most 15%.

[0189] Preferably, in step (b), the pressure is maintained within the desired pressure range for a time sufficient to reduce the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a) to a maximum of 10% of the initial amount, more preferably to a maximum of 5% of the initial amount, even more preferably to a maximum of 3%, and most preferably to a maximum of 1%.

[0190] Preferably, in step (b), the pressure is maintained within the desired pressure range for a time sufficient to reduce the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a) to 0.01-30% of the initial amount, more preferably 0.02-25%, even more preferably 0.05-20%, and most preferably 0.1-10% of the initial amount.

[0191] Preferably, in either embodiment including step (c) or not including step (c), the pressure of the oxidized whey protein solution in step (b) is maintained within the desired pressure range for a time sufficient to reduce the amount of free thiol in the oxidized whey protein solution to at most 15 micromoles per gram of protein, more preferably at most 14 micromoles per gram of protein, even more preferably at most 13 micromoles per gram of protein, and most preferably at most 12 micromoles per gram of protein.

[0192] In some preferred embodiments of the present invention, the pressure of the whey protein solution to be oxidized in step (b) is maintained within a desired pressure range for a time sufficient to reduce the amount of free thiol in the whey protein solution to be oxidized to between 0.001 and 15 micromoles per gram of protein, more preferably between 0.001 and 14 micromoles per gram of protein, even more preferably between 0.001 and 13 micromoles per gram of protein, and most preferably between 0.001 and 12 micromoles per gram of protein.

[0193] Preferably, in either embodiment including step (c) or not including step (c), the pressure of the whey protein solution to be oxidized in step (b) is maintained within the desired pressure range for a time sufficient to reduce the amount of free thiol in the whey protein solution to at most 10 micromoles per gram of protein, more preferably at most 8 micromoles per gram of protein, more preferably at most 5 micromoles per gram of protein, even more preferably at most 3 micromoles per gram of protein, and most preferably at most 2 micromoles per gram of protein.

[0194] In some preferred embodiments of the present invention, the pressure of the whey protein solution to be oxidized in step (b) is maintained within a desired pressure range for a time sufficient to reduce the amount of free thiol in the whey protein solution to be oxidized to 0.001 to 10 micromoles per gram of protein, more preferably 0.01 to 8 micromoles per gram of protein, more preferably 0.01 to 5 micromoles per gram of protein, even more preferably 0.01 to 3 micromoles per gram of protein, and most preferably 0.01 to 2 micromoles per gram of protein.

[0195] Even lower levels of free thiol groups may be desired and in some preferred embodiments of the invention the pressure of the oxidized whey protein solution in step (b) is maintained within a desired pressure range for a time sufficient to reduce the amount of free thiol in the oxidized whey protein solution to at most 1 micromole per gram of protein, more preferably at most 0.7 micromole per gram of protein, even more preferably at most 0.5 micromole per gram of protein, and most preferably at most 0.2 micromole per gram of protein.

[0196] When condition (II) is used in step (b), the temperature is typically in the range of 0 to 65° C., more preferably 5 to 65° C., even more preferably 20 to 60° C., and most preferably 40 to 60° C. Thus, condition (II) is typically used together with condition (I), but condition (I) may be used without condition (II).

[0197] The inventors have found that when step (b) also includes condition (II), lower temperatures are often sufficient. In some preferred embodiments of the present invention, step (b) includes the use of condition (II) and the whey protein solution to be oxidized has a temperature in the range of 0-50°C, more preferably 0-40°C, even more preferably 0-30°C, and most preferably 2-20°C.

[0198] However, in some embodiments of the invention, step (b) involves the use of conditions (II) and the whey protein solution to be oxidized has a temperature in the range of 66 to 160°C, more preferably 70 to 145°C, even more preferably 75 to 120°C, and most preferably 80 to 100°C.

[0199] The inventors have obtained evidence which suggests that a slow increase in temperature in step (b) allows for efficient oxidation of the free thiol groups of the whey proteins.

[0200] In some preferred embodiments of the invention, step (b) comprises increasing the temperature of the whey protein solution to be oxidized in step (b) at a heating rate of at most 2°C / min, more preferably at most 1°C / min, even more preferably at most 0.3°C / min, and most preferably at most 0.1°C / min, up to the maximum oxidation temperature.

[0201] When the whey protein to be oxidized in step (b) has a pH in the range of 6.5 to 7.5, it is particularly useful to carry out step (b) at elevated temperature.

[0202] The temperature may be increased continuously or in steps.

[0203] The pH is measured according to analysis B.

[0204] Furthermore, the inventors have discovered that it may be beneficial to increase the temperature rapidly during step (b), particularly when the pH is in the range of 7.5 to 9.5, and more preferably 7.7 to 8.5.

[0205] In these preferred embodiments of the present invention, when step (b) begins, the temperature of the whey protein solution to be oxidized is in the range of 0-65° C., and in step (b) the temperature of the whey protein solution to be oxidized is increased to a range of 66-160° C., more preferably 70-145° C., even more preferably 75-120° C., and most preferably 80-100° C. The advantages of this approach are illustrated in Example 16.

[0206] In some preferred embodiments of the invention that are particularly useful for the first approach above, step (b) does not include further adding or generating an oxidizing agent capable of oxidizing a thiol group of cysteine ​​in step (b).

[0207] This means that all the oxidizing agent required is added in step (a).

[0208] In another preferred embodiment of the invention, which is particularly useful for the second approach above, step (b) comprises further adding and / or further generating an oxidizing agent capable of oxidizing the thiol group of the cysteine ​​in step (b).

[0209] In such a preferred embodiment of the invention, the maximum amount of oxidizing agent capable of oxidizing the thiol groups of cysteines present in the protein solution to be oxidized in step (b), and the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a); is preferably at most 5:1, more preferably at most 2:1, even more preferably at most 1:1, and most preferably at most 1:2.

[0210] Preferably, and particularly with respect to the second approach, the maximum amount of oxidizing agent capable of oxidizing the thiol groups of cysteines present in the protein solution to be oxidized in step (b); and the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a); is at most 1:5, more preferably at most 1:10, even more preferably at most 1:20, and most preferably at most 1:50.

[0211] Preferably, and particularly with respect to the second approach, the maximum amount of oxidizing agent capable of oxidizing the thiol groups of cysteines present in the protein solution to be oxidized in step (b); and the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a); is preferably 1:1000 to 1:1, more preferably 1:100 to 1:2, even more preferably 1:70 to 1:5, and most preferably 1:60 to 1:15.

[0212] In some preferred embodiments of the invention, the time taken for step (b) is up to 48 hours, more preferably up to 36 hours, even more preferably up to 30 hours, and most preferably up to 25 hours.

[0213] Preferably, the time required for step (b) is 0.1 to 48 hours, more preferably 3 to 36 hours, even more preferably 5 to 30 hours, and most preferably 10 to 25 hours.

[0214] Even faster oxidation steps are suitable and in some preferred embodiments of the invention, the time taken for step (b) is up to 12 hours, more preferably up to 6 hours, even more preferably up to 3 hours, and most preferably up to 1 hour.

[0215] Preferably, the time required for step (b) is from 0.1 to 12 hours, more preferably from 0.1 to 6 hours, even more preferably from 0.1 to 3 hours, and most preferably from 0.1 to 1 hour.

[0216] Rapid reduction of free thiols may be achieved, for example, by performing the method as a continuous process and / or by selecting the parameters of steps (a) and (b) to approach optimum conditions.

[0217] The present inventors have found that it is sufficient to carry out step (b) for about 30 minutes or less.

[0218] In some preferred embodiments of the invention, the time taken for step (b) is up to 40 minutes, more preferably up to 30 minutes, even more preferably up to 20 minutes, and most preferably up to 10 minutes.

[0219] Even faster oxidation steps are suitable and in some preferred embodiments of the invention, the time taken for step (b) is up to 10 minutes, more preferably up to 8 minutes, even more preferably up to 4 minutes, and most preferably up to 2 minutes.

[0220] In some preferred embodiments of the invention, the temperature of the whey protein solution to be oxidized in step (b) is below 65°C, more preferably below 60°C.

[0221] However, as discussed above and shown in Example 16, the inventors have discovered that higher temperatures may be used, especially if the oxidation conditions and the oxidant dosage are adjusted.

[0222] In some preferred embodiments of the invention, step (b) comprises allowing the oxidation to proceed until substantially all of the oxidizing agent capable of oxidizing the cysteine ​​thiol group is consumed.

[0223] In another preferred embodiment of the invention, step (b) comprises terminating the oxidation by contacting the oxidized whey protein solution of step (b) with a component, e.g. an oxidizing agent capable of oxidizing cysteine ​​thiol groups, and an enzyme, catalyst or reactant which removes remaining oxidizing agent.

[0224] Suitable enzymes include catalases, which are capable of dismutating peroxide.

[0225] Suitable reactive agents include antioxidants.

[0226] In a further embodiment of the invention, the oxidized whey protein solution of step (b) still contains some oxidizing agent capable of oxidizing cysteine ​​thiol groups at the end of step (b). However, it is often preferred to keep the content of oxidizing agent capable of oxidizing cysteine ​​thiol groups in the oxidized whey protein solution obtained in step (b) very low.

[0227] Preferably, an amount of an oxidizing agent capable of oxidizing a thiol group of cysteine ​​in the oxidized whey protein solution obtained in step (b); and the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a); is at most 1:50, more preferably at most 1:100, and most preferably at most 1:200.

[0228] Even more preferably, an amount of an oxidizing agent capable of oxidizing a thiol group of cysteine ​​in the oxidized whey protein solution obtained in step (b); and the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a); is at most 1:500, more preferably at most 1:1000, and most preferably at most 1:2000.

[0229] Most preferably, the oxidized whey protein solution obtained in step (b) does not contain detectable levels of said oxidizing agents capable of oxidizing cysteine ​​thiol groups.

[0230] When said oxidizing agent capable of oxidizing cysteine ​​thiol groups mainly comprises peroxides, it is preferred that the content of peroxides in the oxidized whey protein solution obtained in step (b) is low.

[0231] Preferably, the amount of peroxide in the oxidized whey protein solution obtained in step (b); and the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a); is at most 1:50, more preferably at most 1:100, and most preferably at most 1:200.

[0232] Even more preferably, the amount of peroxide in the oxidized whey protein solution obtained in step (b); and the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a); is at most 1:500, more preferably at most 1:1000, and most preferably at most 1:2000.

[0233] Most preferably, the oxidized whey protein solution obtained in step (b) does not contain detectable levels of peroxides.

[0234] When said oxidizing agent capable of oxidizing cysteine ​​thiol groups mainly comprises hydrogen peroxide, it is preferred that the content of hydrogen peroxide in the oxidized whey protein solution obtained in step (b) is low.

[0235] Preferably, the amount of hydrogen peroxide in the oxidized whey protein solution obtained in step (b); and the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a); is at most 1:50, more preferably at most 1:100, and most preferably at most 1:200.

[0236] Even more preferably, the amount of hydrogen peroxide in the oxidized whey protein solution obtained in step (b); and the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a); is at most 1:500, more preferably at most 1:1000, and most preferably at most 1:2000.

[0237] Most preferably, the oxidized whey protein solution obtained in step (b) does not contain detectable levels of hydrogen peroxide.

[0238] Step (b) is preferably carried out as a single incubation step under one or more conditions that promote efficient oxidation, but may also be carried out under one or more conditions, e.g. as a series of incubation steps in which an incubation step is, for example, interrupted when added oxidizing agent is consumed and restarted when more oxidizing agent is added.

[0239] Step (c) is optional in the sense that some embodiments of the invention do not include the heat treatment of step (c), however, step (c) is also preferred and preferred methods of the invention often include step (c).

[0240] It is therefore often preferred that a process which also comprises step (c) comprises subjecting the oxidized whey protein solution obtained in step (b) to a heat treatment step, preferably followed by cooling. A heat treatment in step (c) is preferred if, for example, enzymes have been added beforehand, for example to generate oxidizing agents and / or to remove residual oxidizing agents.

[0241] Heat treatment may then also be used for the purpose of enzyme inactivation.

[0242] Alternatively, or additionally, the heat treatment may consume residual oxidizing agent.

[0243] If step (b) is carried out so as to only partially oxidize the free thiol groups, the heat treatment of step (c) is even more preferred; this means that step (b) alone reduces the content of free thiol groups in the whey protein solution to be oxidized to 20-80% of the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a).

[0244] The inventors have discovered that subsequent heat treatment of the partially oxidized whey protein solution further reduces the free thiol group content, thus reducing the risk of oxidative damage to the whey protein, as this partial oxidation approach requires only a small added amount of oxidizing agent relative to the initial content of free thiol groups.

[0245] The heat treatment in step (c) preferably involves heating the oxidized whey protein solution obtained in step (b) for 5 seconds to 20 minutes to a temperature of 60 to 160°C, more preferably 65 to 95°C, even more preferably 70 to 95°C, and most preferably 80 to 90°C.

[0246] When the oxidation in step (b) is terminated by the addition of an enzyme (e.g., catalase), the heat treatment is preferably carried out for a time sufficient to inactivate the enzyme, preferably using a temperature in the range of 70-160°C, and most preferably 80-150°C.

[0247] The inventors have discovered that heat sterilization can be usefully employed as step (c); in some preferred embodiments of the invention, step (c) comprises heating the oxidized whey protein solution of step (b) to a temperature of at least 100°C for a time sufficient to achieve sterility. Preferably, the heat treatment comprises heating the oxidized whey protein solution of step (b) to a temperature in the range of 140-160°C for a period of 0.1-10 seconds.

[0248] It is particularly preferred that step (c) comprises heat sterilisation if the oxidised whey protein solution is subsequently used as a beverage or the like, In such an embodiment, the sterilised oxidised whey protein solution is filled, preferably by aseptic filling, into suitable containers to provide a filled, sterile beverage comprising the sterilised oxidised whey protein solution.

[0249] In another embodiment of the present invention, the heat treatment in step (c) comprises heating the oxidized whey protein solution obtained in step (b) to a temperature of 60-100°C for 1 second to 1 hour, and more preferably to a temperature of 65-95°C for 2 seconds to 50 minutes, even more preferably to a temperature of 70-95°C for 2 seconds to 40 minutes, and most preferably to a temperature of 80-90°C for 5 seconds to 20 minutes.

[0250] In some embodiments of the present invention, step (d) is optional in the sense that it does not include a drying step, but preferred embodiments often include step (d).

[0251] Therefore, in some preferred embodiments of the present invention, the method further comprises a step (d) of drying the liquid material comprising at least proteins derived from the oxidized whey protein solution obtained in step (b).

[0252] In the context of the present invention, the term "protein derived from the oxidized whey protein solution obtained in step (b)" means that the protein of the liquid raw material is the protein of the oxidized whey protein solution obtained in step (b) or, if the process comprises step (c), is the protein obtained by the heat treatment of step (c).

[0253] Preferably, the liquid material to be dried comprises or consists of: an oxidized whey protein solution or a protein concentrate thereof obtained in step (b), or A heat-treated oxidized whey protein solution or a protein concentrate thereof obtained in step (c).

[0254] In the context of the present invention, a "protein concentrate" of a first liquid is a second liquid in which at least the protein originates from the first liquid, but which has a higher protein content (%) relative to the total solids compared to the first liquid. Preferably, substantially all the solids of the protein concentrate originate from the first liquid. A "protein concentrate" of a first liquid is preferably prepared by ultrafiltration, nanofiltration, reverse osmosis, and / or evaporation. Protein concentration ultrafiltration and / or nanofiltration may be performed, for example, using diafiltration to remove a portion of small non-protein solids. A "protein concentrate" contains the same protein species, and preferably has the same weight percent of whey protein species relative to the total protein as the first liquid. Obtaining a protein concentrate also includes one or more pH adjustments.

[0255] The preparation of the liquid raw material in step (d) may further include pH adjustment, preferably to obtain a liquid raw material having a pH in the range of 6.0 to 8.0, more preferably 6.5 to 7.7, even more preferably 6.7 to 7.5, and most preferably 6.8 to 7.3.

[0256] Thus, the liquid material preferably has a pH in the range of 6.0 to 8.0, more preferably 6.5 to 7.7, even more preferably 6.7 to 7.5, and most preferably 6.8 to 7.3.

[0257] The protein from the oxidized whey protein solution obtained in step (b) preferably contributes to at least 50% w / w of the total protein of the liquid feedstock, more preferably at least 70% w / w, even more preferably 90% w / w, and most preferably at least 99% w / w.

[0258] The liquid raw material is preferably a protein concentrate of the oxidized whey protein solution of step (b) or a heat-treated oxidized whey protein solution obtained in step (c). The liquid raw material may be directly subjected to drying after production, or may be stored in a storage tank until drying.

[0259] It is particularly preferred that the only proteins derived from the oxidized whey protein solution obtained in step (b) are those from the liquid raw material.

[0260] The solids from the oxidized whey protein solution obtained in step (b) preferably contribute to at least 50% w / w of the solids of the liquid feedstock, more preferably at least 70% w / w, even more preferably 90% w / w, and most preferably at least 99% w / w.

[0261] With the possible exception of minerals added during pH adjustment, it is particularly preferred that the only solids resulting from the oxidized whey protein solution obtained in step (b) are proteins from the liquid feedstock.

[0262] The liquid feedstock for drying preferably has a protein content in the range of 8-22% w / w, more preferably 10-18% w / w.

[0263] The liquid feedstock for drying preferably has a solids content in the range of 8-50% w / w, more preferably 10-25% w / w.

[0264] The drying in step (d) preferably converts the liquid material into a powder.

[0265] The drying in step (d) preferably comprises spray drying.

[0266] Further, the method typically includes the step of packing the dried product, typically the powder obtained in step (d).

[0267] The oxidized whey protein composition obtained by the process is the end product of the process, and is preferably an oxidized whey protein solution obtained in step (b), a heat-treated oxidized whey protein solution obtained in step (c), or an oxidized whey protein powder obtained in step (d).

[0268] The process of the present invention can be carried out as a batch process, a semi-batch process, and a continuous process.

[0269] In some preferred embodiments of the invention, the process is carried out as a continuous process. It is particularly preferred to carry out at least steps (a) and (b), or steps (a), (b) and (c), as a continuous process.

[0270] For embodiments of the invention in which the time required for step (b) is relatively short, for example, up to 2 hours, more preferably up to 1 hour, even more preferably up to 30 minutes, even more preferably up to 20 minutes, and most preferably up to 10 minutes, continuous operation is often preferred.

[0271] In another preferred embodiment of the invention, the process is carried out as a semi-batch process.

[0272] A particularly preferred embodiment of the method comprises the following steps (a) to (d): (a) treating a whey protein source (which is a WPI) to provide an oxidized whey protein solution comprising: an oxidizing agent capable of oxidizing the thiol group of cysteine, comprising a peroxide, most preferably hydrogen peroxide, in an amount of at least 90% mol / mol relative to the total amount of oxidizing agent capable of oxidizing the thiol group of cysteine, An oxidizing agent capable of oxidizing the thiol group of cysteine ​​having: a pH in the range of 7.5 to 9.5, most preferably 7.7 to 8.5; a total protein content of 2-9% w / w, most preferably 3-8% w / w, based on the weight of the whey protein solution to be oxidized; A beta-lactoglobulin (BLG) content of at least 50% w / w of total protein; a protein content of at least 86% w / w, most preferably at least 90% w / w, based on total solids; a total fat content of maximum 1% w / w, most preferably maximum 0.2% w / w, based on total solids; and wherein the oxidized whey protein solution further comprises: (i) having a temperature in the range of 20 to 65°C, and most preferably 30 to 65°C; (b) incubating the whey protein solution to be oxidized under one or more conditions capable of oxidizing at least a portion of the free thiols of the BLG molecules of the whey protein solution to be oxidized; wherein the one or more conditions include (I) (I) the whey protein solution to be oxidized has a temperature in the range of 20 to 65°C, and most preferably 30 to 60°C; wherein step (b) further comprises: adjusting the pH of the whey protein solution to be oxidized to a value in the range of 7.5 to 9.5, most preferably in the range of 7.7 to 8.5; carrying out step (b) in order to reduce the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a) to between 30 and 80% of the initial amount, and most preferably to between 50 and 75% of the initial amount; no further oxidizing agent is added in step (b); Terminating the oxidation in step (b) by adding catalase; (c) subjecting the oxidized whey protein solution obtained in step (b) to a heat treatment step which comprises heating at a temperature of at least 75°C for a time sufficient to inactivate catalase, and most preferably at a temperature of between 80 and 95°C for a time sufficient to inactivate catalase; (d) drying the protein-containing liquid material derived from at least the oxidized whey protein solution of step (b); and here the protein from the oxidized whey protein solution obtained in step (b) preferably contributes at least 90% w / w, and most preferably at least 99% w / w, of the protein of said liquid feedstock; the liquid feedstock has a protein content in the range of 8-22% w / w, most preferably 10-18% w / w; the liquid material has a pH in the range of 6.7 to 7.5, and most preferably 6.8 to 7.3; and wherein said drying comprises spray drying.

[0273] In the above particularly preferred embodiment, the pressure applied to the whey protein solution to be oxidized is typically from 0.5 to 99 bar, and most preferably from 1 to 30 bar.

[0274] The oxidized whey protein composition of the present invention is preferably obtainable according to the particularly preferred embodiments described above.

[0275] Instead of drying, the oxidized whey protein solution or protein concentrate thereof obtained in step (c) may be directly filled into a container, preferably a sterile container, by aseptic filling and sealing, or, if the oxidized whey protein solution or protein concentrate thereof obtained in step (c) is not pre-sterile, it may be subjected to heat sterilization as described herein.

[0276] Another particularly preferred embodiment of the method comprises the following steps (a) to (d): (a) treating a whey protein source (which is a WPI) to provide an oxidized whey protein solution comprising: an oxidizing agent capable of oxidizing the thiol group of cysteine, comprising a peroxide, most preferably hydrogen peroxide, in an amount of at least 90% mol / mol relative to the total amount of oxidizing agent capable of oxidizing the thiol group of cysteine, An oxidizing agent capable of oxidizing the thiol group of cysteine ​​having: a pH in the range of 7.5 to 9.5, most preferably 7.7 to 8.5; a total protein content of 2-9% w / w, most preferably 3-8% w / w, based on the weight of the whey protein solution to be oxidized; A beta-lactoglobulin (BLG) content of at least 50% w / w of total protein; a protein content of at least 86% w / w, most preferably at least 90% w / w, based on total solids; a total fat content of maximum 1% w / w, most preferably maximum 0.2% w / w, based on total solids; and wherein the oxidized whey protein solution further comprises: (i) having a temperature in the range of 20 to 65° C., and most preferably 30 to 65° C.; (b) incubating the whey protein solution to be oxidized under one or more conditions capable of oxidizing at least a portion of the free thiols of the BLG molecules of the whey protein solution to be oxidized; wherein the one or more conditions include (I) the following: (I) the whey protein solution to be oxidized has a temperature in the range of 20 to 65°C, and most preferably 30 to 60°C; and here the amount of oxidizing agent capable of oxidizing the thiol groups of cysteines consumed in step (b), excluding the amount of excess oxidizing agent removed at the end of step (b); and the initial amount of free thiol groups in step (a), is from 4:1 to 20:1, and most preferably from 5:1 to 15:1; wherein step (b) further comprises: adjusting the pH of the whey protein solution to be oxidized to a value in the range of 7.5 to 9.5, most preferably 7.7 to 8.5; carrying out step (b) to reduce the amount of free thiol groups in the oxidized whey protein solution to a maximum of 10 micromoles per gram of protein, and most preferably to a maximum of 5 micromoles per gram of protein; no further oxidizing agent is added in step (b); Terminating the oxidation in step (b) by adding catalase; (c) subjecting the oxidized whey protein solution obtained in step (b) to a heat treatment step which comprises heating at a temperature of at least 75°C for a time sufficient to inactivate catalase, and most preferably at a temperature of between 80 and 95°C for a time sufficient to inactivate catalase; (d) drying the protein-containing liquid material derived from at least the oxidized whey protein solution of step (b); and here the protein from the oxidized whey protein solution obtained in step (b) preferably contributes at least 90% w / w, and most preferably at least 99% w / w, of the protein of said liquid feedstock; the liquid feedstock has a protein content in the range of 8-22% w / w, most preferably 10-18% w / w; the liquid material has a pH in the range of 6.7 to 7.5, and most preferably 6.8 to 7.3; and wherein said drying comprises spray drying.

[0277] In the above particularly preferred embodiment, the pressure of the whey protein solution to be oxidized is typically from 0.5 to 99 bar, and most preferably from 1 to 30 bar.

[0278] The oxidized whey protein composition of the present invention is preferably obtainable according to the particularly preferred embodiments described above.

[0279] Instead of drying, the oxidized whey protein solution or protein concentrate thereof obtained in step (c) may be directly filled into a container, preferably a sterile container, by aseptic filling and sealing, or, if the oxidized whey protein solution or protein concentrate thereof obtained in step (c) is not pre-sterile, it may be subjected to heat sterilization as described herein.

[0280] A further particularly preferred embodiment of the method comprises the following steps (a) to (d): (a) treating a whey protein source (which is a WPI) to provide an oxidized whey protein solution comprising: an oxidizing agent capable of oxidizing the thiol group of cysteine, comprising a peroxide, most preferably hydrogen peroxide, in an amount of at least 90% mol / mol relative to the total amount of oxidizing agent capable of oxidizing the thiol group of cysteine, An oxidizing agent capable of oxidizing the thiol group of cysteine ​​having: a pH in the range of 7.5 to 9.5, most preferably 7.7 to 8.5; a total protein content of 2-9% w / w, most preferably 3-8% w / w, based on the weight of the whey protein solution to be oxidized; a β-lactoglobulin (BLG) content of at least 40% w / w of total protein, most preferably at least 50% w / w of total protein; a protein content of at least 86% w / w, most preferably at least 90% w / w, based on total solids; a total fat content of maximum 1% w / w, most preferably maximum 0.2% w / w, based on total solids; and wherein the oxidized whey protein solution further comprises: (i) having a temperature in the range of 0 to 65°C, most preferably 30 to 65°C; (b) incubating the whey protein solution to be oxidized under one or more conditions capable of oxidizing at least a portion of the free thiols of the BLG molecules of the whey protein solution to be oxidized; wherein the one or more conditions include (I) the following: (I) the whey protein solution to be oxidized has a temperature in the range of 20 to 65°C, most preferably 30 to 65°C; and here the amount of oxidizing agent capable of oxidizing the thiol groups of cysteines consumed in step (b), excluding the amount of excess oxidizing agent removed at the end of step (b); and the initial amount of free thiol groups in step (a), is from 1:1 to 10:1, and most preferably from 1:1 to 5:1; wherein step (b) further comprises: carrying out step (b) to reduce the amount of free thiol groups in the oxidized whey protein solution to a maximum of 10 micromoles per gram of protein, and most preferably to a maximum of 5 micromoles per gram of protein; Terminating the oxidation in step (b) by adding catalase; (c) subjecting the oxidized whey protein solution obtained in step (b) to a heat treatment step which comprises heating at a temperature of at least 75°C for a time sufficient to inactivate catalase, and most preferably at a temperature of between 80 and 95°C for a time sufficient to inactivate catalase; (d) preferably drying the protein-containing liquid material derived from at least the oxidized whey protein solution of step (b); and wherein said drying comprises spray drying.

[0281] In the above particularly preferred embodiment, the pressure of the whey protein solution to be oxidized is typically from 0.5 to 99 bar, and most preferably from 1 to 30 bar.

[0282] The oxidized whey protein composition of the present invention is preferably obtainable according to the particularly preferred embodiments described above.

[0283] Instead of drying, the oxidized whey protein solution or protein concentrate thereof obtained in step (c) may be directly filled into a container, preferably a sterile container, by aseptic filling and sealing, or, if the oxidized whey protein solution or protein concentrate thereof obtained in step (c) is not pre-sterile, it may be subjected to heat sterilization as described herein.

[0284] A further particularly preferred embodiment of the method comprises the following steps (a) to (d): (a) treating a whey protein source (which is a WPI) to provide an oxidized whey protein solution comprising: an oxidizing agent capable of oxidizing the thiol group of cysteine, comprising a peroxide, most preferably hydrogen peroxide, in an amount of at least 90% mol / mol relative to the total amount of oxidizing agent capable of oxidizing the thiol group of cysteine, An oxidizing agent capable of oxidizing the thiol group of cysteine ​​having: a pH in the range of 7.5 to 9.5, most preferably 7.7 to 8.5; a total protein content of 2-9% w / w, most preferably 3-8% w / w, based on the weight of the whey protein solution to be oxidized; a β-lactoglobulin (BLG) content of at least 40% w / w of total protein, most preferably at least 50% w / w of total protein; a protein content of at least 86% w / w, most preferably at least 90% w / w, based on total solids; a total fat content of maximum 1% w / w, most preferably maximum 0.2% w / w, based on total solids; and wherein the oxidized whey protein solution further comprises: (i) having a temperature in the range of 0 to 65°C, most preferably 30 to 65°C; and here of the whey protein solution to be oxidized in step (a) an oxidizing agent capable of oxidizing the thiol group of cysteine; and Total amount of free thiol groups is preferably from 2:1 to 30:1, and most preferably from 4:1 to 15:1, (b) incubating the whey protein solution to be oxidized under one or more conditions capable of oxidizing at least a portion of the free thiols of the BLG molecules of the whey protein solution to be oxidized; wherein the one or more conditions include (I) the following: (I) the whey protein solution to be oxidized has a temperature in the range of 20 to 65°C, most preferably 30 to 65°C; wherein step (b) further comprises: carrying out step (b) to reduce the amount of free thiol groups in the oxidized whey protein solution to a maximum of 10 micromoles per gram of protein, and most preferably to a maximum of 5 micromoles per gram of protein; and Terminating the oxidation in step (b) by adding catalase; (c) subjecting the oxidized whey protein solution obtained in step (b) to a heat treatment step which comprises heating at a temperature of at least 75°C for a time sufficient to inactivate catalase, and most preferably at a temperature of between 80 and 95°C for a time sufficient to inactivate catalase; (d) preferably drying the protein-containing liquid material derived from at least the oxidized whey protein solution of step (b); and wherein said drying comprises spray drying.

[0285] In the above particularly preferred embodiment, the pressure of the whey protein solution to be oxidized is typically from 0.5 to 99 bar, and most preferably from 1 to 30 bar.

[0286] The oxidized whey protein composition of the present invention is preferably obtainable according to the particularly preferred embodiments described above.

[0287] Instead of drying, the oxidized whey protein solution or protein concentrate thereof obtained in step (c) may be directly filled into a container, preferably a sterile container, by aseptic filling and sealing, or, if the oxidized whey protein solution or protein concentrate thereof obtained in step (c) is not pre-sterile, it may be subjected to heat sterilization as described herein.

[0288] Another particularly preferred embodiment of the method comprises the following steps (a) to (d): (a) treating a whey protein source (which is a WPI) to provide an oxidized whey protein solution comprising: an oxidizing agent capable of oxidizing the thiol group of cysteine, comprising a peroxide, most preferably hydrogen peroxide, in an amount of at least 90% mol / mol relative to the total amount of oxidizing agent capable of oxidizing the thiol group of cysteine, An oxidizing agent capable of oxidizing the thiol group of cysteine ​​having: a pH in the range of 7.5 to 9.5, most preferably 7.7 to 8.5; a total protein content of 2-9% w / w, most preferably 3-8% w / w, based on the weight of the whey protein solution to be oxidized; a β-lactoglobulin (BLG) content of at least 40% w / w of total protein, most preferably at least 50% w / w of total protein; a protein content of at least 86% w / w, most preferably at least 90% w / w, based on total solids; a total fat content of maximum 1% w / w, most preferably maximum 0.2% w / w, based on total solids; and wherein the oxidized whey protein solution further comprises: (i) having a temperature in the range of 0 to 65°C, most preferably 30 to 65°C; and here of the whey protein solution to be oxidized in step (a) an oxidizing agent capable of oxidizing the thiol group of cysteine; Total amount of free thiol groups is preferably from 2:1 to 30:1, and most preferably from 4:1 to 15:1, (b) incubating the whey protein solution to be oxidized under one or more conditions capable of oxidizing at least a portion of the free thiols of the BLG molecules of the whey protein solution to be oxidized; wherein the one or more conditions include (I) the following: (I) the whey protein solution to be oxidized has a temperature in the range of 20 to 65°C, most preferably 30 to 65°C; wherein step (b) further comprises: carrying out step (b) to reduce the amount of free thiol groups in the oxidized whey protein solution to a maximum of 10 micromoles per gram of protein, and most preferably to a maximum of 5 micromoles per gram of protein; (d) preferably drying the protein-containing liquid material derived from at least the oxidized whey protein solution of step (b); and wherein said drying comprises spray drying.

[0289] In the above particularly preferred embodiment, the pressure of the whey protein solution to be oxidized is typically from 0.5 to 99 bar, and most preferably from 1 to 30 bar.

[0290] The oxidized whey protein composition of the present invention is preferably obtainable according to the particularly preferred embodiments described above.

[0291] Instead of drying, the oxidized whey protein solution or protein concentrate thereof obtained in step (b) may be directly filled into a container, preferably a sterile container, by aseptic filling and sealing, or, if the oxidized whey protein solution or protein concentrate thereof obtained in step (b) is not pre-sterile, it may be subjected to heat sterilization as described herein.

[0292] Another particularly preferred embodiment of the method comprises the following steps (a) to (d): (a) treating a whey protein source (which is a WPI) to provide an oxidized whey protein solution comprising: an oxidizing agent capable of oxidizing the thiol group of cysteine, comprising a peroxide, most preferably hydrogen peroxide, in an amount of at least 90% mol / mol relative to the total amount of oxidizing agent capable of oxidizing the thiol group of cysteine, An oxidizing agent capable of oxidizing the thiol group of cysteine ​​having: a pH in the range of 7.5 to 9.5, most preferably 7.7 to 8.5; a total protein content of 2-9% w / w, most preferably 3-8% w / w, based on the weight of the whey protein solution to be oxidized; a β-lactoglobulin (BLG) content of at least 40% w / w of total protein, most preferably at least 50% w / w of total protein; a protein content of at least 86% w / w, most preferably at least 90% w / w, based on total solids; a total fat content of maximum 1% w / w, most preferably maximum 0.2% w / w, based on total solids; and here of the whey protein solution to be oxidized in step (a) an oxidizing agent capable of oxidizing the thiol group of cysteine; and Total amount of free thiol groups is from 1:1.5 to 10:1, even more preferably from 1:1 to 8:1, and most preferably from 1:1 to 3:1; The oxidized whey protein solution further comprises: (i) having a temperature in the range of 0 to 65°C, most preferably 30 to 65°C; (b) incubating the whey protein solution to be oxidized under one or more conditions capable of oxidizing at least a portion of the free thiols of the BLG molecules of the whey protein solution to be oxidized; wherein the one or more conditions include (I) the following: (I) the whey protein solution to be oxidized has a temperature in the range of 20 to 65°C, most preferably 30 to 65°C; wherein step (b) further comprises: carrying out step (b) to reduce the initial amount of free thiol groups in the oxidized whey protein solution of step (a) to between 30 and 80% of the initial amount, and most preferably to between 50 and 75% of the initial amount; Optionally, terminating the oxidation of step (b) by adding catalase; (c) subjecting the oxidized whey protein solution obtained in step (b) to a heat treatment step comprising heating the solution to a temperature of 70 to 95°C for a period of 2 seconds to 40 minutes; (d) preferably drying the protein-containing liquid material derived from at least the oxidized whey protein solution of step (b); and wherein said drying comprises spray drying.

[0293] In the above particularly preferred embodiment, the pressure of the whey protein solution to be oxidized is typically from 0.5 to 99 bar, and most preferably from 1 to 30 bar.

[0294] The oxidized whey protein composition of the present invention is preferably obtainable according to the particularly preferred embodiments described above.

[0295] Instead of drying, the oxidized whey protein solution or protein concentrate thereof obtained in step (b) may be directly filled into a container, preferably a sterile container, by aseptic filling and sealing, or, if the oxidized whey protein solution or protein concentrate thereof obtained in step (b) is not pre-sterile, it may be subjected to heat sterilization as described herein.

[0296] A further particularly preferred embodiment of the method comprises the following steps (a) to (d): (a) treating a whey protein source (which is a WPI) to provide an oxidized whey protein solution comprising: an oxidizing agent capable of oxidizing the thiol group of cysteine, comprising a peroxide, most preferably hydrogen peroxide, in an amount of at least 90% mol / mol relative to the total amount of oxidizing agent capable of oxidizing the thiol group of cysteine, An oxidizing agent capable of oxidizing the thiol group of cysteine ​​having: a pH in the range of 7.5 to 9.5, most preferably 7.7 to 8.5; a total protein content of 2-9% w / w, most preferably 3-8% w / w, based on the weight of the whey protein solution to be oxidized; a β-lactoglobulin (BLG) content of at least 40% w / w of total protein, most preferably at least 50% w / w of total protein; a protein content of at least 86% w / w, most preferably at least 90% w / w, based on total solids; a total fat content of maximum 1% w / w, most preferably maximum 0.2% w / w, based on total solids; and here of the whey protein solution to be oxidized in step (a) an oxidizing agent capable of oxidizing the thiol group of cysteine; and Total amount of free thiol groups is from 1:1.5 to 10:1, even more preferably from 1:1.5 to 8:1, and most preferably from 1:1.5 to 3:1; The oxidized whey protein solution further comprises: (i) having a temperature in the range of 0 to 65°C, most preferably 30 to 65°C; (b) incubating the whey protein solution to be oxidized under one or more conditions capable of oxidizing at least a portion of the free thiols of the BLG molecules of the whey protein solution to be oxidized; wherein the one or more conditions include (I) the following: (I) the whey protein solution to be oxidized has a temperature in the range of 20 to 65°C, most preferably 30 to 65°C; wherein step (b) further comprises: carrying out step (b) in order to reduce the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a) to between 30 and 80% of the initial amount, and most preferably to between 50 and 75% of the initial amount; Optionally, terminating the oxidation of step (b) by adding catalase; (c) subjecting the oxidized whey protein solution obtained in step (b) to a heat treatment step comprising heating the solution to a temperature of 70 to 95°C for a period of 2 seconds to 40 minutes; (d) preferably drying the protein-containing liquid material derived from at least the oxidized whey protein solution of step (b); and wherein said drying comprises spray drying.

[0297] In the above particularly preferred embodiment, the pressure of the whey protein solution to be oxidized is typically from 0.5 to 99 bar, and most preferably from 1 to 30 bar.

[0298] The oxidized whey protein composition of the present invention is preferably obtainable according to the particularly preferred embodiments described above.

[0299] Instead of drying, the oxidized whey protein solution or protein concentrate thereof obtained in step (c) may be directly filled into a container, preferably a sterile container, by aseptic filling and sealing, or, if the oxidized whey protein solution or protein concentrate thereof obtained in step (c) is not pre-sterile, it may be subjected to heat sterilization as described herein.

[0300] Yet another particularly preferred embodiment of the method comprises the following steps (a) to (d): (a) treating a whey protein source (which is a WPI) to provide an oxidized whey protein solution comprising: an oxidizing agent capable of oxidizing the thiol group of cysteine, comprising a peroxide, most preferably hydrogen peroxide, in an amount of at least 90% mol / mol relative to the total amount of oxidizing agent capable of oxidizing the thiol group of cysteine, An oxidizing agent capable of oxidizing the thiol group of cysteine ​​having: a pH in the range of 7.5 to 9.5, most preferably 7.7 to 8.5; a total protein content of 2-9% w / w, most preferably 3-8% w / w, based on the weight of the whey protein solution to be oxidized; a β-lactoglobulin (BLG) content of at least 40% w / w of total protein, most preferably at least 50% w / w of total protein; a protein content of at least 86% w / w, most preferably at least 90% w / w, based on total solids; a total fat content of maximum 1% w / w, most preferably maximum 0.2% w / w, based on total solids; and here of the whey protein solution to be oxidized in step (a) an oxidizing agent capable of oxidizing the thiol group of cysteine; and Total amount of free thiol groups is from 1:1.5 to 10:1, even more preferably from 1:1 to 8:1, and most preferably from 1:1 to 3:1; The oxidized whey protein solution further comprises: (i) having a temperature in the range of 0 to 65°C, most preferably 30 to 65°C; (b) incubating the whey protein solution to be oxidized under one or more conditions capable of oxidizing at least a portion of the free thiols of the BLG molecules of the whey protein solution to be oxidized; wherein the one or more conditions include (I) the following: (I) the whey protein solution to be oxidized has a temperature in the range of 20 to 65°C, most preferably 30 to 65°C; wherein step (b) further comprises: carrying out step (b) in order to reduce the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a) to between 30 and 80% of the initial amount, and most preferably to between 50 and 75% of the initial amount; Optionally, terminating the oxidation of step (b) by adding catalase; (c) subjecting the oxidized whey protein solution obtained in step (b) to a heat treatment step comprising heating the solution to a temperature of 70-95° C. for a time sufficient to reduce the amount of free thiol groups in the oxidized whey protein solution to a maximum of 10 micromoles per gram of protein, and most preferably to a maximum of 5 micromoles per gram of protein; (d) preferably drying the protein-containing liquid material derived from at least the oxidized whey protein solution of step (b); and wherein said drying comprises spray drying.

[0301] In the above particularly preferred embodiment, the pressure of the whey protein solution to be oxidized is typically from 0.5 to 99 bar, and most preferably from 1 to 30 bar.

[0302] The oxidized whey protein composition of the present invention is preferably obtainable according to the particularly preferred embodiments described above.

[0303] Instead of drying, the oxidized whey protein solution or protein concentrate thereof obtained in step (c) may be directly filled into a container, preferably a sterile container, by aseptic filling and sealing, or, if the oxidized whey protein solution or protein concentrate thereof obtained in step (c) is not pre-sterile, it may be subjected to heat sterilization as described herein.

[0304] A further particularly preferred embodiment of the method comprises the following steps (a) to (d): (a) treating a whey protein source (which is a WPI) to provide an oxidized whey protein solution comprising: an oxidizing agent capable of oxidizing the thiol group of cysteine, comprising a peroxide, most preferably hydrogen peroxide, in an amount of at least 90% mol / mol relative to the total amount of oxidizing agent capable of oxidizing the thiol group of cysteine, An oxidizing agent capable of oxidizing the thiol group of cysteine ​​having: a pH in the range of 7.5 to 9.5, most preferably 7.7 to 8.5; a total protein content of 2-9% w / w, most preferably 3-8% w / w, based on the weight of the whey protein solution to be oxidized; a β-lactoglobulin (BLG) content of at least 40% w / w of total protein, most preferably at least 50% w / w of total protein; a protein content of at least 86% w / w, most preferably at least 90% w / w, based on total solids; a total fat content of maximum 1% w / w, most preferably maximum 0.2% w / w, based on total solids; and here of the whey protein solution to be oxidized in step (a) an oxidizing agent capable of oxidizing the thiol group of cysteine; and Total amount of free thiol groups is from 1:1.5 to 10:1, even more preferably from 1:1.5 to 8:1, and most preferably from 1:1.5 to 3:1; The oxidized whey protein solution further comprises: (i) having a temperature in the range of 0 to 65°C, most preferably 30 to 65°C; (b) incubating the whey protein solution to be oxidized under one or more conditions capable of oxidizing at least a portion of the free thiols of the BLG molecules of the whey protein solution to be oxidized; wherein the one or more conditions include (I) the following: (I) the whey protein solution to be oxidized has a temperature in the range of 20 to 65°C, most preferably 30 to 65°C; wherein step (b) further comprises: carrying out step (b) in order to reduce the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a) to between 30 and 80% of the initial amount, and most preferably to between 50 and 75% of the initial amount; Optionally, terminating the oxidation of step (b) by adding catalase; (c) subjecting the oxidized whey protein solution obtained in step (b) to a heat treatment step comprising heating the solution to a temperature of 70-95° C. for a time sufficient to reduce the amount of free thiol groups in the oxidized whey protein solution to a maximum of 10 micromoles per gram of protein, and most preferably to a maximum of 5 micromoles per gram of protein; (d) preferably drying the protein-containing liquid material derived from at least the oxidized whey protein solution of step (b); and wherein said drying comprises spray drying.

[0305] In the above particularly preferred embodiment, the pressure of the whey protein solution to be oxidized is typically from 0.5 to 99 bar, and most preferably from 1 to 30 bar.

[0306] The oxidized whey protein composition of the present invention is preferably obtainable according to the particularly preferred embodiments described above.

[0307] Instead of drying, the oxidized whey protein solution or protein concentrate thereof obtained in step (c) may be directly filled into a container, preferably a sterile container, by aseptic filling and sealing, or, if the oxidized whey protein solution or protein concentrate thereof obtained in step (c) is not pre-sterile, it may be subjected to heat sterilization as described herein.

[0308] A further particularly preferred embodiment of the method comprises the following steps (a) to (d): (a) treating a whey protein source (which is a WPI) to provide an oxidized whey protein solution comprising: an oxidizing agent capable of oxidizing the thiol group of cysteine, comprising a peroxide, most preferably hydrogen peroxide, in an amount of at least 90% mol / mol relative to the total amount of oxidizing agent capable of oxidizing the thiol group of cysteine, An oxidizing agent capable of oxidizing the thiol group of cysteine ​​having: a pH in the range of 7.5 to 9.5, most preferably 7.7 to 8.5; a total protein content of 2-9% w / w, most preferably 3-8% w / w, based on the weight of the whey protein solution to be oxidized; a β-lactoglobulin (BLG) content of at least 40% w / w of total protein, most preferably at least 50% w / w of total protein; a protein content of at least 86% w / w, most preferably at least 90% w / w, based on total solids; a total fat content of maximum 1% w / w, most preferably maximum 0.2% w / w, based on total solids; and here of the whey protein solution to be oxidized in step (a) an oxidizing agent capable of oxidizing the thiol group of cysteine; and Total amount of free thiol groups is from 1:1.5 to 10:1, even more preferably from 1:1 to 8:1, and most preferably from 1:1 to 3:1; The oxidized whey protein solution further comprises: (i) having a temperature in the range of 0 to 160°C, most preferably 0 to 65°C; (b) incubating the whey protein solution to be oxidized under one or more conditions capable of oxidizing at least a portion of the free thiols of the BLG molecules of the whey protein solution to be oxidized; wherein the one or more conditions include (I) the following: (I) the whey protein solution to be oxidized has a temperature in the range of 70 to 160°C, most preferably 75 to 100°C; wherein step (b) further comprises: carrying out step (b) to reduce the amount of free thiol groups in the oxidized whey protein solution to a maximum of 10 micromoles per gram of protein, and most preferably to a maximum of 5 micromoles per gram of protein; Preferably, wherein step (b) takes a maximum of 1 hour, and most preferably a maximum of 10 minutes; (d) preferably drying the protein-containing liquid material derived from at least the oxidized whey protein solution of step (b); and wherein said drying comprises spray drying.

[0309] In the above particularly preferred embodiment, the pressure of the whey protein solution to be oxidized is typically from 0.5 to 99 bar, and most preferably from 1 to 30 bar.

[0310] The oxidized whey protein composition of the present invention is preferably obtainable according to the particularly preferred embodiments described above.

[0311] Instead of drying, the oxidized whey protein solution or protein concentrate thereof obtained in step (b) may be directly filled into a container, preferably a sterile container, by aseptic filling and sealing, or, if the oxidized whey protein solution or protein concentrate thereof obtained in step (b) is not pre-sterile, it may be subjected to heat sterilization as described herein.

[0312] Another particularly preferred embodiment of the method comprises the following steps (a) to (d): (a) treating a whey protein source (which is a WPI) to provide an oxidized whey protein solution comprising: an oxidizing agent capable of oxidizing the thiol group of cysteine, comprising a peroxide, most preferably hydrogen peroxide, in an amount of at least 90% mol / mol relative to the total amount of oxidizing agent capable of oxidizing the thiol group of cysteine, An oxidizing agent capable of oxidizing the thiol group of cysteine ​​having: a pH in the range of 7.5 to 9.5, most preferably 7.7 to 8.5; a total protein content of 2-9% w / w, most preferably 3-8% w / w, based on the weight of the whey protein solution to be oxidized; a β-lactoglobulin (BLG) content of at least 40% w / w of total protein, most preferably at least 50% w / w of total protein; a protein content of at least 86% w / w, most preferably at least 90% w / w, based on total solids; a total fat content of maximum 1% w / w, most preferably maximum 0.2% w / w, based on total solids; and here of the whey protein solution to be oxidized in step (a) an oxidizing agent capable of oxidizing the thiol group of cysteine; and Total amount of free thiol groups is from 1:1.5 to 10:1, even more preferably from 1:1.5 to 8:1, and most preferably from 1:1.5 to 3:1; The oxidized whey protein solution further comprises: (i) having a temperature in the range of 0 to 160°C, most preferably 0 to 65°C; (b) incubating the whey protein solution to be oxidized under one or more conditions capable of oxidizing at least a portion of the free thiols of the BLG molecules of the whey protein solution to be oxidized; wherein the one or more conditions include (I) the following: (I) the whey protein solution to be oxidized has a temperature in the range of 70 to 160°C, most preferably 75 to 100°C; wherein step (b) further comprises: carrying out step (b) to reduce the amount of free thiol groups in the oxidized whey protein solution to a maximum of 10 micromoles per gram of protein, and most preferably to a maximum of 5 micromoles per gram of protein; Preferably, the time taken for step (b) is at most 1 hour, and most preferably at most 10 minutes; (d) preferably drying the protein-containing liquid material derived from at least the oxidized whey protein solution of step (b); and wherein said drying comprises spray drying.

[0313] In the above particularly preferred embodiment, the pressure of the whey protein solution to be oxidized is typically from 0.5 to 99 bar, and most preferably from 1 to 30 bar.

[0314] The oxidized whey protein composition of the present invention is preferably obtainable according to the particularly preferred embodiments described above.

[0315] Instead of drying, the oxidized whey protein solution or protein concentrate thereof obtained in step (b) may be directly filled into a container, preferably a sterile container, by aseptic filling and sealing, or, if the oxidized whey protein solution or protein concentrate thereof obtained in step (b) is not pre-sterile, it may be subjected to heat sterilization as described herein.

[0316] A further and particularly preferred embodiment of the method comprises the following steps (a) and (b): (a) treating a whey protein source (which is a WPI) to provide an oxidized whey protein solution comprising: an oxidizing agent capable of oxidizing the thiol group of cysteine, comprising a peroxide, most preferably hydrogen peroxide, in an amount of at least 90% mol / mol relative to the total amount of oxidizing agent capable of oxidizing the thiol group of cysteine, An oxidizing agent capable of oxidizing the thiol group of cysteine ​​having: a pH in the range of 7.5 to 9.5, most preferably 7.7 to 8.5; a total protein content of 2-9% w / w, most preferably 3-8% w / w, based on the weight of the whey protein solution to be oxidized; a β-lactoglobulin (BLG) content of at least 40% w / w of total protein, most preferably at least 50% w / w of total protein; a protein content of at least 86% w / w, most preferably at least 90% w / w, based on total solids; a total fat content of maximum 1% w / w, most preferably maximum 0.2% w / w, based on total solids; and here of the whey protein solution to be oxidized in step (a) an oxidizing agent capable of oxidizing the thiol group of cysteine; and Total amount of free thiol groups, is from 1:1.5 to 10:1, even more preferably from 1:1 to 8:1, and most preferably from 1:1 to 3:1; The oxidized whey protein solution further comprises: (i) having a temperature in the range of 0 to 160°C, most preferably 0 to 65°C; (b) incubating the whey protein solution to be oxidized under one or more conditions capable of oxidizing at least a portion of the free thiols of the BLG molecules of the whey protein solution to be oxidized; wherein the one or more conditions include (I) the following: (I) the whey protein solution to be oxidized has a temperature in the range of 100 to 160°C, most preferably 130 to 150°C, for a time sufficient to provide a sterile oxidized whey protein solution; wherein step (b) further comprises: carrying out step (b) to reduce the amount of free thiol groups in the oxidized whey protein solution to a maximum of 10 micromoles per gram of protein, and most preferably to a maximum of 5 micromoles per gram of protein; Preferably, wherein step (b) takes a maximum of 1 hour, and most preferably a maximum of 10 minutes; and where: The oxidized whey protein solution or protein concentrate thereof obtained in step (b) is filled into containers, preferably sterile containers, by aseptic filling and sealing to provide a sterile filled liquid oxidized whey protein solution.

[0317] In the above particularly preferred embodiment, the pressure of the whey protein solution to be oxidized is typically from 0.5 to 99 bar, and most preferably from 1 to 30 bar.

[0318] The oxidized whey protein composition of the present invention is preferably obtainable according to the particularly preferred embodiments described above.

[0319] A further particularly preferred embodiment of the method comprises the following steps (a) and (b): (a) treating a whey protein source (which is a WPI) to provide an oxidized whey protein solution comprising: an oxidizing agent capable of oxidizing the thiol group of cysteine, comprising a peroxide, most preferably hydrogen peroxide, in an amount of at least 90% mol / mol relative to the total amount of oxidizing agent capable of oxidizing the thiol group of cysteine, An oxidizing agent capable of oxidizing the thiol group of cysteine ​​having: a pH in the range of 7.5 to 9.5, most preferably 7.7 to 8.5; a total protein content of 2-9% w / w, most preferably 3-8% w / w, based on the weight of the whey protein solution to be oxidized; a β-lactoglobulin (BLG) content of at least 40% w / w of total protein, most preferably at least 50% w / w of total protein; a protein content of at least 86% w / w, most preferably at least 90% w / w, based on total solids; a total fat content of maximum 1% w / w, most preferably maximum 0.2% w / w, based on total solids; and here of the whey protein solution to be oxidized in step (a) an oxidizing agent capable of oxidizing the thiol group of cysteine; and Total amount of free thiol groups is from 1:1.5 to 10:1, even more preferably from 1:1.5 to 8:1, and most preferably from 1:1.5 to 3:1; The oxidized whey protein solution further comprises: (i) having a temperature in the range of 0 to 160°C, most preferably 0 to 65°C; (b) incubating the whey protein solution to be oxidized under one or more conditions capable of oxidizing at least a portion of the free thiols of the BLG molecules of the whey protein solution to be oxidized; wherein the one or more conditions include (I) the following: (I) the whey protein solution to be oxidized has a temperature in the range of 100 to 160°C, most preferably 130 to 150°C, for a time sufficient to provide a sterile oxidized whey protein solution; wherein step (b) further comprises: carrying out step (b) to reduce the amount of free thiol groups in the oxidized whey protein solution to a maximum of 10 micromoles per gram of protein, and most preferably to a maximum of 5 micromoles per gram of protein; Preferably, wherein step (b) takes a maximum of 1 hour, and most preferably a maximum of 10 minutes; and here The oxidized whey protein solution or protein concentrate thereof obtained in step (b) is filled into containers, preferably sterile containers, by aseptic filling and sealing to provide a sterile filled liquid oxidized whey protein solution.

[0320] In the above particularly preferred embodiment, the pressure of the whey protein solution to be oxidized is typically from 0.5 to 99 bar, and most preferably from 1 to 30 bar.

[0321] The oxidized whey protein composition of the present invention is preferably obtainable according to the particularly preferred embodiments described above.

[0322] Yet another aspect of the present invention relates to an oxidized whey protein composition comprising: A protein content of at least 30% w / w of total solids; a fat content preferably of maximum 3% w / w based on total solids; Up to 15 micromoles of free thiol groups per gram of protein; a tryptophan content, preferably of at least 0.7% w / w based on total protein; a methionine content preferably of at least 0.3% w / w based on total protein; preferably a kynurenine content of up to 0.2 micrograms per mg of protein; a content of protein-bound sulfur preferably in the range of 100 to 600 micromoles per gram of protein, a content of protein-bound cysteine ​​residues forming disulfide bonds preferably in the range of 150-400 micromoles per gram of protein; a protein weight average molecular weight preferably in the range of 18 kDa to 10,000 kDa, more preferably 50 to 8,000 kDa, and most preferably 80 to 5,000 kDa; having and Preferably, at least 60% w / w, more preferably at least 80% w / w, even more preferably at least 90% w / w, and most preferably at least 99% w / w of the protein has a molecular weight between 18 kDa and 10 000 kDa.

[0323] The oxidized whey protein composition typically has a pH in the range of 5.5 to 9.5.

[0324] In some preferred embodiments of the present invention, the oxidized whey protein composition has a pH in the range of 5.5 to 9.5, more preferably 6.0 to 8.5, even more preferably 6.2 to 8.0, and most preferably 6.5 to 7.5.

[0325] In some preferred embodiments of the invention, the oxidized whey protein composition has a total protein content of at least 30% w / w based on the total solids of the oxidized whey protein composition, more preferably at least 50% w / w based on the total solids of the oxidized whey protein composition, even more preferably at least 75% w / w, and most preferably at least 85% w / w.

[0326] Preferably, the oxidized whey protein composition has a total protein content in the range of 30-99% based on the total solids of the oxidized whey protein composition, more preferably 50-97% w / w based on the total solids of the oxidized whey protein composition, even more preferably 75-96% w / w, and most preferably at least 85-95% w / w.

[0327] Preferably, the oxidized whey protein composition has a fat content of up to 3% w / w based on total solids.

[0328] Even lower fat levels are typically preferred, and it is often preferred for the oxidized whey protein composition to have a total fat content of maximum 1% w / w of total solids, more preferably maximum 0.5% w / w of total solids, even more preferably maximum 0.2% w / w, and most preferably maximum 0.1% w / w.

[0329] The oxidized whey protein composition may contain varying amounts of carbohydrates.

[0330] However, it is often preferred that the oxidized whey protein composition has a carbohydrate content of up to 65% w / w based on total solids.

[0331] Even lower carbohydrate levels are typically preferred, and it is often preferred for the oxidized whey protein composition to have a carbohydrate content of up to 20% w / w of total solids, more preferably up to 8% w / w of total solids, even more preferably up to 2% w / w, and most preferably up to 0.2% w / w.

[0332] The oxidized whey protein composition preferably has an ash content of maximum 8% w / w based on total solids, more preferably maximum 6% w / w, even more preferably maximum 5%, and most preferably maximum 4.0%.

[0333] In some preferred embodiments of the invention, the oxidized whey protein composition has an ash content of from 0.4 to 8% w / w of total solids, more preferably from 0.5 to 6% w / w of total solids, even more preferably from 0.5 to 5% w / w, and most preferably from 0.6 to 4.0% w / w.

[0334] The oxidized whey protein composition preferably has a combined magnesium and calcium content of maximum 1% w / w based on total solids, more preferably maximum 0.7% w / w, even more preferably maximum 0.5%, and most preferably maximum 0.2%.

[0335] In some preferred embodiments of the invention, the oxidized whey protein composition has a combined magnesium and calcium content of 0.01-1% w / w of total solids, more preferably up to 0.001-0.7% w / w of total solids, even more preferably 0.01-0.5% w / w, and most preferably 0.01-0.2% w / w.

[0336] The inventors have found evidence to suggest that oxidized whey protein compositions containing up to 15 micromoles of free thiol groups per gram of protein are capable of reducing the level of off-flavors in a heat treated whey protein beverage containing 3% whey protein compared to non-oxidized whey protein.

[0337] In some preferred embodiments of the invention, the oxidized whey protein composition comprises free thiol groups in an amount of up to 15 micromoles per gram protein, more preferably up to 14 micromoles per gram protein, even more preferably up to 13 micromoles per gram protein, and most preferably up to 12 micromoles per gram protein.

[0338] In some preferred embodiments of the invention, the oxidized whey protein composition comprises free thiol groups in an amount of 0.001-15 micromoles per gram protein, more preferably 0.01-14 micromoles per gram protein, even more preferably 0.01-13 micromoles per gram protein, and most preferably 0.01-12 micromoles per gram protein.

[0339] However, it is often preferred that the oxidized whey protein composition comprises lower levels of free thiol groups, particularly when the oxidized whey protein composition is to be used in a heat treated high protein beverage (e.g., containing 6% or more whey protein).Thus, in some preferred embodiments of the invention, the oxidized whey protein composition comprises free thiol groups in an amount of at most 10 micromoles per gram protein, more preferably at most 8 micromoles per gram protein, more preferably at most 5 micromoles per gram protein, even more preferably at most 3 micromoles per gram protein, and most preferably at most 2 micromoles per gram protein.

[0340] Preferably, the oxidized whey protein composition comprises free thiol groups in an amount of 0.01 to 10 micromoles per gram protein, more preferably 0.01 to 8 micromoles per gram protein, more preferably 0.01 to 5 micromoles per gram protein, even more preferably 0.01 to 3 micromoles per gram protein, and most preferably 0.01 to 2 micromoles per gram protein.

[0341] Even lower levels of free thiol groups may be desired and in some preferred embodiments of the invention the oxidized whey protein composition comprises free thiol groups in an amount of at most 1 micromole per gram protein, more preferably at most 0.7 micromole per gram protein, even more preferably at most 0.5 micromole per gram protein, and most preferably at most 0.2 micromole per gram protein.

[0342] In some preferred embodiments of the invention, the oxidized whey protein composition has a tryptophan content of at least 0.7% w / w of total protein, more preferably at least 0.8% w / w of total protein, even more preferably at least 0.9% w / w, and most preferably at least 1.0% w / w.

[0343] Preferably, the oxidized whey protein composition has a tryptophan content of 0.7-3% w / w of total protein, more preferably 0.8-2.6% w / w of total protein, even more preferably 0.9-2.4% w / w, and most preferably 1.0-2.2% w / w.

[0344] Alternatively or preferably, the oxidized whey protein composition has a tryptophan content of 0.7-3% w / w of total protein, more preferably 0.8-3% w / w of total protein, even more preferably 0.9-3% w / w, and most preferably 1.0-3% w / w.

[0345] In some preferred embodiments of the invention, the oxidized whey protein composition has a methionine content of at least 0.3% w / w of total protein, more preferably at least 0.4% w / w of total protein, even more preferably at least 0.5% w / w, and most preferably at least 0.6% w / w.

[0346] Preferably, the oxidized whey protein composition has a methionine content of 0.3-3.3% w / w of total protein, more preferably 0.4-3.2% w / w of total protein, even more preferably 0.5-3.2% w / w, and most preferably 0.6-3.2% w / w.

[0347] A higher lower limit for methionine is often preferred and in some preferred embodiments of the invention the oxidized whey protein composition has a methionine content of 1.0-3.3% w / w of total protein, more preferably 1.3-3.2% w / w of total protein, even more preferably 1.6-3.2% w / w, and most preferably 1.8-3.2% w / w.

[0348] Preferably, the oxidized whey protein composition has a kynurenine content of at most 0.2 micrograms per mg protein, more preferably at most 0.05 micrograms per mg protein, even more preferably at most 0.01 micrograms per mg protein, and most preferably at most 0.001 micrograms per mg protein. It is particularly preferred that the oxidized whey protein composition contains no detectable kynurenine.

[0349] Kynurenine content is quantified according to Poojary et al., "Selective and sensitive UHPLC-ESI-Orbitrap MS method to quantify protein oxidation markers"; Talanta, Volume 234, Issue 1, November 2021 (available online; July 2021).

[0350] Kynurenine is believed by the inventors to be a useful marker of tryptophan oxidation and is partially responsible for the yellowing in heat sterilized whey protein beverages that results from over-oxidized proteins, and furthermore, kynurenine is undesirable from a health standpoint.

[0351] Preferably, the oxidized whey protein composition has a protein bound sulfur content in the range of 100-600 micromoles per gram protein, more preferably in the range of 200-500 micromoles per gram protein, and most preferably in the range of 250-500 micromoles per gram protein.

[0352] Preferably, the oxidized whey protein composition has a content of protein-bound cysteine ​​residues forming disulfide bonds in the range of 150-400 micromoles per gram protein, more preferably 160-350 micromoles per gram protein, and most preferably 170-300 micromoles per gram protein.

[0353] The inventors have discovered that it is beneficial for the protein particle size of the oxidized whey protein composition to be less than 10,000 kDa, preferably smaller, to avoid opacity in clear beverage applications and also to avoid viscosity increase and drying of the oxidized whey protein during concentration.

[0354] In some preferred embodiments of the present invention, the weight average molecular weight of the protein in the oxidized whey protein composition is in the range of 18 kDa to 10,000 kDa, more preferably 30 to 9,000 kDa, even more preferably 50 to 8,000 kDa, and most preferably 80 to 5,000 kDa.

[0355] Preferably, at least 60% w / w of the protein of the oxidized whey protein composition has a molecular weight of between 18 kDa and 10,000 kDa, more preferably at least 80% w / w, even more preferably at least 90% w / w, and most preferably at least 99% w / w.

[0356] More preferably, at least 60% w / w of the protein of the oxidized whey protein composition has a molecular weight of from 50 kDa to 8000 kDa, more preferably at least 80% w / w, even more preferably at least 90% w / w, and most preferably at least 99% w / w.

[0357] Even more preferably, at least 60% w / w, more preferably at least 80% w / w, even more preferably at least 90% w / w, and most preferably at least 99% w / w of the protein of the oxidized whey protein composition has a molecular weight between 80 kDa and 5000 kDa.

[0358] In another preferred embodiment of the present invention, the proteins of the oxidized whey protein composition have a weight average molecular weight in the range of 18 kDa to 200 kDa, more preferably 30 to 150 kDa, and most preferably 30 to 100 kDa.

[0359] The inventors have discovered that the lower the weight average molecular weight of the protein, the higher the total protein concentration possible upon concentration, for example by ultrafiltration or nanofiltration, prior to spray drying.

[0360] Preferably, at least 60% w / w of the protein of the oxidized whey protein composition has a molecular weight of between 18 kDa and 200 kDa, more preferably at least 80% w / w, even more preferably at least 90% w / w, and most preferably at least 99% w / w.

[0361] More preferably, at least 60% w / w of the protein of the oxidized whey protein composition has a molecular weight of between 18 kDa and 150 kDa, more preferably at least 80% w / w, even more preferably at least 90% w / w, and most preferably at least 99% w / w.

[0362] Even more preferably, at least 60% w / w, more preferably at least 80% w / w, even more preferably at least 90% w / w, and most preferably at least 99% w / w of the protein of the oxidized whey protein composition has a molecular weight between 18 kDa and 100 kDa.

[0363] The inventors have found evidence that it may be beneficial for the majority of the proteins in the oxidized whey protein composition to have a molecular weight of at least 30 kDa, which is likely due to dimerization of oxidized BLG.

[0364] Thus, preferably at least 60% w / w, more preferably at least 80% w / w, even more preferably at least 90% w / w, and most preferably at least 99% w / w of the protein of the oxidized whey protein composition has a molecular weight of between 30 kDa and 200 kDa.

[0365] More preferably, at least 60% w / w of the protein of the oxidized whey protein composition has a molecular weight of between 30 kDa and 150 kDa, more preferably at least 80% w / w, even more preferably at least 90% w / w, and most preferably at least 99% w / w.

[0366] Even more preferably, at least 60% w / w, more preferably at least 80% w / w, even more preferably at least 90% w / w, and most preferably at least 99% w / w of the protein of the oxidized whey protein composition has a molecular weight of between 30 kDa and 100 kDa.

[0367] The oxidized whey protein composition is preferably prepared by a process comprising the oxidation of a whey protein source, preferably an aqueous solution of the whey protein source. Preferred embodiments of the whey protein source are described herein. Whey protein isolate is particularly preferred as a whey protein source.

[0368] In some preferred embodiments of the present invention, the oxidized whey protein compositions of the present invention are obtainable by the methods described herein.

[0369] In some preferred embodiments of the invention, the oxidized whey protein composition is in liquid form, and preferably in the form of an aqueous liquid. The oxidized whey protein composition in liquid form preferably has a solids content of up to 0.1-50% w / w, more preferably 1-35% w / w, even more preferably 5-30% w / w, and most preferably 10-30% w / w.

[0370] In some preferred embodiments of the invention, the oxidized whey protein composition is in a solid form, preferably a powder, preferably prepared by spray drying. The oxidized whey protein composition in powder form preferably has a solids content of at least 90% w / w, more preferably at least 93% w / w, even more preferably at least 94% w / w, and most preferably at least 95% w / w.

[0371] The portion of the oxidized whey protein composition and the oxidized whey protein solution that does not contribute to the solids content is preferably water.

[0372] The portion of the oxidized whey protein composition that does not contribute to the solids content preferably comprises water in an amount of at least 80% w / w, more preferably at least 90% w / w, even more preferably 95% w / w, and more preferably at least 99% w / w.

[0373] In one particularly preferred embodiment of the invention, the oxidized whey protein composition comprises: a protein content of at least 86% w / w based on total solids, and most preferably at least 90% based on total solids; a fat content of maximum 1% w / w based on total solids, and most preferably a maximum of 0.2%; up to 10 micromoles free thiol groups per mg of protein, and most preferably up to 5 micromoles free thiol groups per mg of protein; a tryptophan content of 0.7-3% w / w based on total protein, and most preferably a tryptophan content of 1.0-3% w / w based on total protein, a methionine content of 0.3 to 3.3% w / w based on total protein, and most preferably a methionine content of 1.3 to 3.2% w / w based on total protein, A kynurenine content of maximum 0.2 micrograms per mg of protein, and most preferably maximum 0.01 micrograms per mg of protein.

[0374] In the above particularly preferred embodiments of the present invention, the oxidized whey protein composition preferably comprises: A content of protein-bound sulfur in the range of 100-600 micromoles per gram of protein; and Content of protein-bound cysteine ​​residues forming disulfide bonds in the range of 150-400 micromoles per gram of protein.

[0375] Furthermore, in the above particularly preferred embodiments of the present invention, the oxidized whey protein composition preferably comprises: A content of protein-bound sulfur in the range of 100-600 micromoles per gram of protein; and Content of protein-bound cysteine ​​residues forming disulfide bonds in the range of 150-400 micromoles per gram of protein.

[0376] It is often further preferred that at least 60% w / w of the protein in the oxidized whey protein composition in the above particularly preferred embodiments has a molecular weight of from 30 kDa to 9000 kDa, more preferably at least 80% w / w, even more preferably at least 90% w / w, and most preferably at least 99% w / w.

[0377] The pH of the above particularly preferred embodiments of the oxidized whey protein composition is preferably in the range of 6.2 to 8.0, and most preferably 6.5 to 7.5.

[0378] In some preferred embodiments of the present invention, the oxidized whey protein composition is a sterile oxidized whey protein composition, preferably a packaged sterile oxidized whey protein composition, preferably in sterile form, a liquid oxidized whey protein composition or a sterile powdered oxidized whey protein composition.

[0379] Yet another aspect of the present invention relates to a process for producing a food product comprising: processing the oxidized whey protein composition described herein; and / or combining the oxidized whey protein composition and / or the processed oxidized whey protein composition with one or more further ingredients, and optionally processing the combination.

[0380] Preferred examples of food products are heat treated beverages, and preferably heat sterilized beverages having a pH of 5.5 to 8.5.

[0381] Thus, a more specific aspect of the present invention relates to a process for producing a heat-treated, and preferably heat-sterilized, beverage having a pH of 5.5 to 8.5, more preferably a pH of 6.5 to 7.5, comprising the steps (1) and (2) of: (1) combining an oxidized whey protein composition as described herein with one or more ingredients to obtain a liquid mixture having a pH of 5.5 to 8.5, more preferably a pH of 6.5 to 7.5, The liquid mixture is a sufficient amount of the oxidized whey protein composition to contribute at least 0.5% w / w protein; and · Water, Including, A combining step; (2) filling the liquid mixture into containers, preferably sterile containers; and Here, the liquid mixture is heat treated, preferably heat sterilized, before and / or after filling.

[0382] The oxidized whey protein composition described herein is preferably the sole protein source of the food product or the heat sterilized beverage, and therefore the sole protein source of the liquid mixture.

[0383] The inventors have discovered that it is beneficial to keep the free thiol content of the liquid mixture low prior to heat treatment in order to prevent the development of an unpleasant odor similar to that of rotten eggs.

[0384] Thus, in some preferred embodiments of the invention, the liquid mixture comprises, prior to heat sterilization, at most 60 micromoles free thiol groups per 100 g of liquid mixture, more preferably at most 40 micromoles free thiol groups per 100 g of liquid mixture, even more preferably at most 30 micromoles free thiol groups per 100 g of liquid mixture, and most preferably at most 30 micromoles free thiol groups per 100 g of liquid mixture.

[0385] Even lower free thiol group contents are often required, and in some preferred embodiments of the invention, the liquid mixture contains, prior to heat sterilization, at most 20 micromoles of free thiol groups per 100 g of liquid mixture, more preferably at most 15 micromoles of free thiol groups per 100 g of liquid mixture, even more preferably at most 10 micromoles of free thiol groups per 100 g of liquid mixture, and most preferably at most 5 micromoles of free thiol groups per 100 g of liquid mixture.

[0386] The liquid mixture preferably contains a total amount of protein in the range of 0.5 to 15% w / w relative to the weight of the liquid mixture, more preferably 1 to 10% w / w relative to the weight of the liquid mixture, even more preferably 2 to 9% w / w relative to the weight of the liquid mixture, and most preferably 3 to 8% w / w relative to the weight of the liquid mixture.

[0387] Alternatively and preferably, the liquid mixture comprises a total amount of protein in the range of 4 to 15% w / w by weight of the liquid mixture, more preferably 5 to 14% by weight of the liquid mixture, even more preferably 6 to 13% w / w by weight of the liquid mixture, and most preferably 8 to 12% w / w by weight of the liquid mixture.

[0388] The oxidized whey protein composition of the present invention preferably contributes at least 30% w / w of the total protein of the liquid mixture, more preferably at least 50% w / w of the total protein of the liquid mixture, even more preferably at least 70% w / w of the total protein of the liquid mixture, and most preferably at least 80% w / w of the total protein of the liquid mixture.

[0389] Even higher contributions are often preferred and in some preferred embodiments of the invention, the oxidized whey protein composition of the invention contributes to at least 90% w / w of the total protein of the liquid mixture, more preferably at least 95% w / w of the total protein of the liquid mixture, even more preferably at least 99% w / w of the total protein of the liquid mixture, and most preferably 100% w / w of the total protein of the liquid mixture.

[0390] When the oxidized whey protein composition is used in combination with other protein sources, it is preferable to use sources that have a relatively low content of free thiol groups.

[0391] In some preferred embodiments of the invention, the liquid mixture comprises total protein in an amount of at least 15% w / w of total solids, more preferably at least 20% w / w of total solids, and most preferably at least 25% w / w, and most preferably at least 30% w / w.

[0392] For example, if the beverage is intended as a sports protein beverage, the total protein may comprise a greater proportion of the total solids.Thus, in some preferred embodiments of the present invention, the liquid mixture comprises total protein in an amount of at least 80% w / w of total solids, more preferably at least 90% w / w of total solids, even more preferably at least 92% w / w, and most preferably at least 94% w / w.

[0393] The liquid mixture typically has a solids content of from 0.5 to 50% w / w, more preferably from 1 to 35% w / w, even more preferably from 2 to 20% w / w, and most preferably from 3 to 10% w / w.

[0394] The portion of the liquid mixture not constituted by solids preferably comprises water. The portion of the liquid mixture not constituted by solids preferably comprises water in an amount of at least 80% w / w, more preferably at least 90% w / w, even more preferably 95% w / w, and more preferably at least 99% w / w.

[0395] In some preferred embodiments of the present invention, the caloric content of the liquid mixture is at most 100 kcal / 100g, more preferably at most 80 kcal / 100g, even more preferably at most 70 kcal / 100g, and most preferably at most 60 kcal / 100g. Preferably, the caloric content of the liquid mixture may be 2-100 kcal / 100g, more preferably 4-80 kcal / 100g, even more preferably 8-70 kcal / 100g, and most preferably 12-60 kcal / 100g. These embodiments are preferred, for example, for sports applications where the protein source is the main source of energy.

[0396] In other preferred embodiments of the invention, the caloric content of the liquid mixture is greater than 100 kcal / 100g, more preferably at least 120 kcal / 100g, even more preferably at least 140 kcal / 100g, and most preferably at least 150 kcal / 100g. Preferably, the caloric content of the liquid mixture may be between 101 and 300 kcal / 100g, more preferably between 120 and 280 kcal / 100g, even more preferably between 140 and 270 kcal / 100g, and most preferably between 150 and 260 kcal / 100g. These embodiments are preferred, for example, for clinical nutrition where the protein source is accompanied by significant amounts of carbohydrates and fat.

[0397] The compositional features and preferences described with respect to the heat treated beverage apply equally to the liquid mixture.

[0398] The pH of the liquid mixture may range from slightly acidic to slightly alkaline.

[0399] A liquid mixture with a near neutral pH is particularly preferred for producing a beverage with a near neutral pH. In some preferred embodiments of the present invention, the pH of the liquid mixture is in the range of 5.5 to 8.0, more preferably 6.0 to 7.5, even more preferably 6.2 to 7.3, and most preferably 6.3 to 7.2.

[0400] In another preferred embodiment of the present invention, the pH of the liquid mixture is in the range of 6.0 to 7.5, more preferably 6.2 to 7.5, and most preferably 6.3 to 7.5.

[0401] In a further preferred embodiment of the present invention, the pH of the liquid mixture is in the range of 6.0 to 8.0, more preferably 6.6 to 7.7, even more preferably 6.7 to 7.6, and most preferably 6.8 to 7.5.

[0402] Generally, any suitable food grade acid or food grade base may be used to adjust the pH of the liquid mixture. A person skilled in the art will understand suitable means for adjusting the pH. Suitable food grade bases include sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, or ammonium hydroxide. Alternatively, KOH or NaOH may be used to adjust the pH. Suitable food grade acids include, for example, citric acid, hydrochloric acid, malic acid, or tartaric acid, or phosphoric acid.

[0403] In some preferred embodiments of the present invention, the viscosity of the liquid mixture is -1 at a maximum of 200 cP, more preferably at 20° C. and a shear rate of 300 s -1 at a maximum of 100 cP, and even more preferably at 20° C. and a shear rate of 300 s-1 at a maximum of 50 cP, and most preferably at 20° C. and a shear rate of 300 s -1 The maximum is 20 cP.

[0404] The liquid mixture is typically prepared by mixing the appropriate ingredients with the oxidized whey protein composition. Where powdered ingredients are used, it is often preferable to hydrate these prior to heat treatment, as well as sometimes to homogenize the liquid mixture prior to heat treatment.

[0405] In some preferred embodiments, the oxidized whey protein composition is provided in powder form, and is preferably mixed with water or an aqueous liquid and is hydrated prior to heat treatment.

[0406] In other preferred embodiments, the oxidized whey protein composition is provided in liquid form, such as an oxidized whey protein solution obtained in step (b) or step (c). In some preferred embodiments, the oxidized whey protein composition is an oxidized whey protein solution obtained in step (b) that includes catalase used to remove residual peroxide oxidizing agent. The oxidized whey protein solution obtained in step (b) is not subjected to step (c), but is subjected to: mixing with one or more further ingredients required to produce said beverage; Optionally, homogenizing; Heat sterilization by heating at a temperature in the range of 140-150 degrees for 1-10 seconds; cooling the heat sterilized beverage; and The sterilized beverage is aseptically filled into suitable sterile containers which are then sealed.

[0407] The inventors have discovered that heat sterilization in such beverage processing can replace step (c) of the method described herein and also inactivates catalase, contributing to a further reduction in the content of free thiol groups.

[0408] The filling in step (2) may be by any suitable filling technique and any suitable container may be used to fill the liquid mixture.

[0409] However, in a preferred embodiment of the invention, the filling in step (2) is aseptic filling, i.e., the liquid mixture is filled under aseptic conditions. For example, the aseptic filling may be performed using an aseptic filling system and preferably involves filling the liquid mixture into one or more sterile containers.

[0410] Aseptic filling and sealing is particularly preferred where the liquid mixture is sterile or has a very low microbial presence prior to filling.

[0411] Examples of useful containers include bottles, cartons, bricks, and / or bags.

[0412] The heat step of the process preferably brings the liquid mixture to a temperature of at least 70°C.

[0413] In some preferred embodiments of the process of the present invention, the liquid mixture of step (1) is subjected to a heat treatment including at least pasteurization and then filled in step (2).

[0414] In another embodiment of the process of the present invention, the filled liquid mixture of step (2) is subjected to a heat treatment including at least pasteurization.

[0415] In some preferred embodiments, the heat treatment comprises heating the liquid mixture to a temperature in the range of 70-80°C.

[0416] In some preferred embodiments of the present invention, the temperature of the heat treatment is in the range of 70 to 80°C, preferably in the range of 70 to 79°C, more preferably in the range of 71 to 78°C, even more preferably in the range of 72 to 77°C, and most preferably in the range of 73 to 76°C (e.g., approximately 75°C).

[0417] Preferably, the heat treatment is carried out for a period of 1 second to 60 minutes when carried out at a temperature in the range of 70-80° C. The longest heating time is optimal for the lowest temperature within the temperature range, and vice versa.

[0418] In other preferred embodiments, the temperature of the heat treatment is 70° C. for at least 60 minutes, or preferably 75° C. for at least 45 minutes, or preferably 80° C. for at least 30 minutes, or preferably 85° C. for at least 22 minutes, or preferably 90° C. for at least 10 minutes.

[0419] In a particularly preferred embodiment of the present invention, the heat treatment is carried out at 70 to 78°C for 1 second to 30 minutes, more preferably at 71 to 77°C for 1 minute to 25 minutes, and even more preferably at 72 to 76°C for 2 minutes to 20 minutes.

[0420] In some preferred embodiments of the present invention, the heat treatment process comprises heating at a temperature of 85° C. to 95° C. for 1 to 30 minutes.

[0421] For example, the temperature of the heat treatment may be at least 81°C, preferably at least 91°C, preferably at least 95°C, more preferably at least 100°C, even more preferably at least 120°C, and most preferably at least 140°C.

[0422] In a particularly preferred embodiment of the invention, the heat treatment comprises heating the liquid mixture to a temperature in the range of 100-160° C. for a time sufficient to sterilize the liquid mixture. This preferably comprises heating the liquid mixture to a temperature in the range of 120-155° C. for a time sufficient to achieve sterility, typically 0.1 seconds to 10 minutes, and more preferably heating to a temperature in the range of 140-155° C. for a time sufficient to achieve sterility, typically 0.1 to 30 seconds. Liquid heat treatment to render a liquid sterile is also referred to as heat sterilization.

[0423] Another preferred type of heat treatment is a UHT type sterilization treatment, which typically involves heating to a temperature in the range of 135-146°C for a time sufficient to achieve sterility, with heating times typically in the range of 1-10 seconds.

[0424] Alternatively and preferably, the heat treatment involves heating at a temperature in the range of 145-180°C for a time sufficient to achieve sterility, typically for a time in the range of 0.01-2 seconds, and more preferably at a temperature in the range of 150-180°C for a time in the range of 0.01-0.3 seconds.

[0425] The implementation of the heat treatment may include the use of equipment such as plate or tubular heat exchangers, scraped surface heat exchangers or retort systems. Alternatively, direct steam heating may be used, for example, using direct steam injection, direct steam infusion or spray cooking, which is particularly preferred for heat treatments above 95°C. Furthermore, such direct steam heating is preferably used in combination with flash cooling. Suitable examples of the implementation of spray cooking are described in WO2009113858A1; this reference is incorporated herein for all purposes. Suitable examples of the implementation of direct steam injection and direct steam infusion are described in WO2009113858A1 and WO2010 / 085957A3; these references are incorporated herein for all purposes. High temperature processing in general is described, for example, in "Thermal technologies in food processing" (ISBN 185573558X); this reference is incorporated herein by reference for all purposes.

[0426] In some preferred embodiments of the invention, the heat treatment comprises or consists of a retort heat treatment, preferably carried out at a temperature of at least 80°C, and more preferably at least 95°C, even more preferably at least 100°C, and most preferably at least 120°C, and preferably for a time sufficient to render the treatment liquid sterile.

[0427] In another preferred embodiment of the invention, the heat treatment comprises or consists of steam injection or spray cooking, preferably carried out at a temperature of at least 100°C, and more preferably at least 120°C, even more preferably at least 130°C, and most preferably at least 140°C, and preferably for a time sufficient to render the treatment liquid sterile.

[0428] In some preferred embodiments of the present invention, pasteurization is combined with physical microbial reduction.

[0429] Useful examples of physical microbial reduction include one or more of sterile filtration, ultraviolet light, high pressure treatment, pulsed electric field treatment, and ultrasound.

[0430] In some preferred embodiments of the invention, the heat treatment is a sterilizing heat treatment, thereby resulting in a sterile liquid mixture and therefore a sterile beverage. Such sterilization may be achieved, for example, by combining sterile filtration with pasteurization, or by carrying out a heat treatment at at least 100° C. for a time sufficient for sterilization.

[0431] After the heat treatment, it is advantageous to cool the liquid mixture. According to a preferred embodiment of the process of the present invention, after the heat treatment, the heat treated liquid mixture is cooled, preferably to 0-70°C, preferably to 0-60°C, even more preferably to 0-30°C, and most preferably to 0-20°C.

[0432] If the heat treatment does not sterilize the liquid mixture, the heat-treated liquid mixture is preferably cooled to 0 to 15°C, more preferably 1 to 10°C, and most preferably 1 to 5°C after heat treatment.

[0433] The cooling may be before or after the filling step.

[0434] The cooling typically involves flash cooling and / or conventional heat exchangers.

[0435] At least partial cooling by flash cooling is often preferred, especially after a heat treatment for autoclave sterilization. Flash cooling typically results in the evaporation of some of the volatile compounds of the cooling liquid. Whey protein beverages having a pH in the range of 5.5 to 8.5 are particularly susceptible to the development of unpleasant odors during heat treatment, and these odors are in part evaporated from the heat-treated liquid and are released in the vicinity of the flash cooling system. This is disadvantageous; operators operating the heat treatment system are exposed to the off-odors, which may further pose health problems.

[0436] Advantageously, the inventors have discovered that flash cooling of heat treated beverages derived from the oxidized whey protein compositions results in little, and in some cases no, release of such objectionable odors.

[0437] The process of the present invention can be carried out as a batch process, a semi-batch process, or a continuous process.

[0438] Another particular aspect of the present invention relates to a process for producing a heat treated, and preferably heat sterilized, beverage, comprising carrying out steps (a), (b) and optionally step (c) of the method described herein to obtain the oxidized whey protein composition and then filling the oxidized whey protein composition according to step (2) as described herein.

[0439] When the oxidized whey protein composition is to be used directly as a beverage, it is preferred that step (b) and / or step (c) comprises a heat treatment for heat sterilization, ie a heat treatment for rendering the treatment liquid sterile.

[0440] As noted above, such heat treatments typically require heating the liquid to be treated to a temperature in the range of 100-160° C. for a time sufficient for sterilization. Suitable time / temperature combinations for such heat treatments are described herein.

[0441] Yet another aspect of the present invention relates to a food product comprising the oxidized whey protein composition of the present invention, preferably in an amount contributing at least 0.5% w / w protein by weight of the food product, said food product preferably further comprising at least one non-whey ingredient.

[0442] The term "non-whey ingredients" refers to ingredients that are not present in the oxidized whey protein composition or in the non-oxidized whey protein concentrate.

[0443] A narrower aspect of the invention relates to a heat treated, and preferably heat sterilized, beverage having a pH between 5.5 and 8.5 and comprising an oxidized whey protein composition as described herein in an amount sufficient for a protein contribution of at least 0.5% w / w.

[0444] The inventors have found that the heat treated beverages of the present invention are advantageous in that they have a better odor than comparable prior art beverages, and the H2S content of the beverages is unexpectedly low.

[0445] The heat treated beverage preferably has a pH of 5.5 to 8.5, more preferably a pH of 6.0 to 8.0, even more preferably a pH of 6.3 to 7.5, and most preferably a pH of 6.5 to 7.5.

[0446] Preferably, the heat treated beverage, and preferably the heat sterilized beverage, having a pH of 5.5 to 8.5, has an H2S content of at most 5 micromol / L, more preferably 3 micromol / L, even more preferably 1.0 micromol / L, and most preferably at most 0.7 micromol / L.

[0447] It is particularly preferred that the heat treated, and preferably heat sterilized, beverages, having a pH of 5.5 to 8.5, have an H2S content of at most 5 micromol / L, more preferably 3 micromol / L, even more preferably 1.0 micromol / L, and most preferably at most 0.7 micromol / L, one hour after production.

[0448] It is even more preferred that the heat treated beverage, and preferably the heat sterilized beverage, having a pH of 5.5 to 8.5, has an H2S content of at most 5 micromol / L, more preferably 3 micromol / L, even more preferably 1.0 micromol / L, and most preferably at most 0.7 micromol / L, 7 days after production.

[0449] The present inventors have discovered that the heat-treated beverage has a particularly pleasant odor compared to a pH-neutral whey protein-containing beverage that has been subjected to a similar heat treatment according to the prior art.

[0450] It is particularly preferred that the heat-treated beverage is sterile.

[0451] The heat-treated beverage is preferably a filled heat-treated beverage, preferably filled in a sealed container, such as, for example, a bottle, etc. Such filled heat-treated beverages are highly appealing to consumers, typically have a long shelf life at ambient temperature, and can be transported and consumed on demand by the consumer.

[0452] In some preferred embodiments of the present invention, the heat treated beverage has a shelf life at ambient temperature of at least six months, more preferably at least one year, and even more preferably at least two years.

[0453] Preferably, the heat-treated beverage contains a total protein amount in the range of 0.5 to 15% w / w relative to the weight of the beverage, more preferably 1 to 10% w / w relative to the weight of the beverage, even more preferably 2 to 9% w / w relative to the weight of the beverage, and most preferably 3 to 8% w / w relative to the weight of the beverage.

[0454] Alternatively and preferably, the heated-treated beverage contains a total protein amount in the range of 4 to 15% w / w relative to the weight of the heated-treated beverage, more preferably 5 to 14% w / w relative to the weight of the heated-treated beverage, even more preferably 6 to 13% w / w relative to the weight of the heated-treated beverage, and most preferably 8 to 12% w / w relative to the weight of the heated-treated beverage.

[0455] The oxidized whey protein composition of the present invention preferably contributes at least 30% w / w of the total protein of the heat treated beverage, more preferably at least 50% w / w of the total protein, even more preferably at least 70% w / w of the total protein, and most preferably at least 80% w / w of the total protein.

[0456] Even higher contributions are often preferred and in some preferred embodiments of the invention, the oxidized whey protein composition of the invention contributes at least 90% w / w of the total protein of the heat treated beverage, more preferably at least 95% w / w of the total protein, even more preferably at least 99% w / w of the total protein, and most preferably 100% w / w of the total protein.

[0457] When the oxidized whey protein composition is used in combination with other protein sources, it is preferable to use sources that have a relatively low content of free thiol groups.

[0458] In some preferred embodiments of the invention, the heat treated beverage preferably comprises total protein in an amount of at least 15% w / w of total solids, more preferably at least 20% w / w of total solids, and most preferably at least 25% w / w, and most preferably at least 30% w / w. The lower end of these ranges is particularly preferred for beverages for clinical nutrition, which often contain significant amounts of fat and carbohydrate in addition to protein.

[0459] For example, if the beverage is intended as a sports protein beverage, the total protein may contribute a greater proportion of the total solids. Thus, in some preferred embodiments of the present invention, the heat treated beverage comprises total protein in an amount of at least 80% w / w of total solids, more preferably at least 90% w / w of total solids, even more preferably at least 92% w / w, and most preferably at least 94% w / w.

[0460] The heat treated beverage preferably has a solids content of 0.5-50% w / w, more preferably 1-35% w / w, even more preferably 2-20% w / w, and most preferably 3-10% w / w.

[0461] The portion of the heat-treated beverage not constituted by solid matter preferably comprises water. The portion of the heat-treated beverage not constituted by solid matter preferably comprises water in an amount of at least 80% w / w, more preferably at least 90% w / w, even more preferably 95% w / w, and more preferably at least 99% w / w.

[0462] In some preferred embodiments of the present invention, the heat-treated beverage has a calorie content of at most 100 kcal / 100g, more preferably at most 80 kcal / 100g, even more preferably at most 70 kcal / 100g, and most preferably at most 60 kcal / 100g. Preferably, the heat-treated beverage may have a calorie content of 2-100 kcal / 100g, more preferably 4-80 kcal / 100g, even more preferably 8-70 kcal / 100g, and most preferably 12-60 kcal / 100g. These embodiments are preferred, for example, for sports applications where a protein source is the main energy source.

[0463] In other preferred embodiments of the present invention, the heat-treated beverage has a caloric content of more than 100 kcal / 100 g, more preferably at least 120 kcal / 100 g, even more preferably at least 140 kcal / 100 g, and most preferably at least 150 kcal / 100 g. Preferably, the heat-treated beverage may have a caloric content of 101-300 kcal / 100 g, more preferably 120-280 kcal / 100 g, even more preferably 140-270 kcal / 100 g, and most preferably 150-260 kcal / 100 g. These embodiments are preferred, for example, for clinical nutrition, where the protein source is accompanied by a significant amount of carbohydrates and fat.

[0464] The heat-treated beverage of the present invention may contain major nutrients other than protein (eg, carbohydrates and / or lipids, etc.).

[0465] In some embodiments of the present invention, the heat treated beverage further comprises carbohydrates. The total carbohydrate content in the heat treated beverage of the present invention depends on the intended use of the heat treated beverage.

[0466] The carbohydrate of the filled, heat treated beverage is preferably provided by one or more carbohydrate sources.

[0467] Useful carbohydrate sources may be selected from the group consisting of: Sucrose, maltose, dextrose, galactose, maltodextrin, corn syrup solids, sucromalt, glucose polymers, corn syrup, modified starch, resistant starch, carbohydrates derived from rice, isomaltulose, sucrose, glucose, fructose, lactose, high fructose corn syrup, honey, sugar alcohols, fructooligosaccharides, soy fiber, corn fiber, guar gum, konjac flour, polydextrose, Fibersol, and combinations thereof. In some embodiments of the present invention, the filled heat treated beverage comprises non-digestible sugars such as fructans, the fructans comprising inulin or fructooligosaccharides.

[0468] In some preferred embodiments of the present invention, the heat-treated beverage comprises carbohydrates in the range of 0-95% of the total energy content of the beverage, more preferably in the range of 10-85% of the total energy content of the beverage, even more preferably in the range of 20-75% of the total energy content of the beverage, and most preferably in the range of 30-60% of the total energy content of the beverage.

[0469] The assessment of the energy contribution of nutrients in nutritional products is well known to those skilled in the art and involves calculating the energy contribution of each group of nutrients to the total energy content. For example, carbohydrates are known to contribute 4.0 kcal per gram of carbohydrate; proteins to contribute 4.0 kcal per gram of protein; and fats to contribute 9.0 kcal per gram of fat. The total energy content is assessed by burning the composition in question using a bomb calorimeter.

[0470] An even lower carbohydrate content is often preferred, and therefore in some preferred embodiments of the invention, preferably in the range of 0-30% of the total energy content of the beverage, more preferably in the range of 0-20% of the total energy content of the beverage, and even more preferably in the range of 0-10% of the total energy content of the beverage.

[0471] In some preferred embodiments of the invention, the beverage is particularly useful as a sports beverage, for example comprising a total carbohydrate content of up to 75% of the total energy content (E%) of the beverage, more preferably up to 40E%, even more preferably up to 10E%, and most preferably up to 5E%.

[0472] In some preferred embodiments of the invention, the filled, heat-treated beverages are particularly useful as nutritionally incomplete dietary supplements, for example comprising a total carbohydrate content in the range of 70-95% of the total energy content (E%) of the beverage, preferably in the range of 80-90E%.

[0473] In some preferred embodiments of the present invention, the heat-treated beverage comprises a total carbohydrate content in the range of 30-60% of the total energy content of the beverage, and most preferably in the range of 35-50E%, making such beverages particularly useful for nutritionally complete beverages.

[0474] In some embodiments of the present invention, the heat treated beverage further comprises at least one additional ingredient selected from the group consisting of vitamins, flavorings, minerals, sweeteners, antioxidants, food grade acids, lipids, carbohydrates, prebiotics, probiotics, and combinations thereof.

[0475] The additional ingredients can be used to adjust the nutritional contribution as well as the taste and flavor characteristics of the beverage.

[0476] In one embodiment of the invention, the beverage comprises at least one high intensity sweetener (HIS), preferably selected from the group consisting of aspartame, cyclamate, sucralose, acesulfame salts, neotame, saccharin, stevia extract, steviol glycosides (such as rebaudioside A), or combinations thereof.

[0477] In some embodiments of the present invention, it is particularly preferred that the sweetener comprises or consists of one or more high intensity sweeteners.

[0478] HIS can be either natural or artificial sweeteners, but typically have a sweetening intensity at least 10 times that of sucrose.

[0479] When used, the total amount of HIS in the beverage is typically in the range of 0.001-2% w / w. Preferably, the total amount of HIS is in the range of 0.005-1% w / w. Most preferably, the total amount of HIS is in the range of 0.01-0.5% w / w.

[0480] The choice of sweetener may depend on the beverage to be produced; for example, in the case of beverages in which no energy contribution from the sweetener is desired, high intensity sweeteners (e.g., aspartame, acesulfame K or sucralose) may be used, whereas for beverages with a natural profile, natural sweeteners (e.g., steviol glycosides, sorbitol or sucrose) may be used.

[0481] Additionally, the sweetener may preferably comprise or consist of one or more polyol sweeteners.

[0482] Non-limiting examples of useful polyol sweeteners include reduced maltose, mannitol, lactitol, sorbitol, inositol, xylitol, threitol, galactitol, or combinations thereof. When using polyol sweeteners, the total amount of polyol sweetener in the beverage is typically in the range of 1-20% w / w. More preferably, the total amount of polyol sweetener in the beverage is in the range of 2-15% w / w. Even more preferably, the total amount of polyol sweetener in the beverage is in the range of 4-10% w / w.

[0483] In some preferred embodiments of the present invention, the heat treated beverage comprises: carbohydrates in a total amount of up to 1% w / w, more preferably up to 0.5% w / w, and most preferably up to 0.1% w / w; and A total amount of HIS in the range of 0.001-2% w / w, more preferably in the range of 0.005-1% w / w, and most preferably in the range of 0.01-0.5% w / w.

[0484] In some embodiments of the present invention, the heat-treated beverage further comprises lipids. The total lipid content of the heat-treated beverage of the present invention depends on the intended use of the heat-treated beverage.

[0485] In some preferred embodiments of the present invention, the lipid content of the heat-treated beverage is in the range of 0 to 50% of the total energy content of the beverage, or preferably in the range of 0 to 40% of the total energy content of the beverage, or preferably in the range of 0 to 30% of the total energy content of the beverage, or preferably in the range of 0 to 20% of the total energy content of the beverage, or preferably in the range of 0 to 10% of the total energy content of the beverage, or preferably in the range of 0 to 5% of the total energy content of the beverage.

[0486] In some preferred embodiments of the invention, the beverage comprises a total amount of lipids of at most 10E%, more preferably at most 5E%, and most preferably at most 1E%.

[0487] In some preferred embodiments of the invention, the heat-treated beverages are particularly useful as nutritionally incomplete dietary supplements, for example comprising a total lipid content of up to 10% of the total energy content of the beverage, preferably up to 1E%.

[0488] In some preferred embodiments of the invention, the beverage comprises a total carbohydrate content of at most 10E%, more preferably at most 5E%, and most preferably at most 1E%.

[0489] In some preferred embodiments of the present invention, the viscosity of the heat-treated beverage is -1At 20° C. and a shear rate of 300 s -1 at a maximum of 100 cP, and even more preferably at 20° C. and a shear rate of 300 s -1 at a maximum of 50 cP, and most preferably at 20° C. and a shear rate of 300 s -1 The maximum is 20 cP.

[0490] The inventors have found that the oxidized whey protein compositions of the present invention are useful in clear beverages, and in some preferred embodiments of the present invention, the turbidity of the heat treated beverage is at most 400 NTU, more preferably at most 100 NTU, even more preferably at most 50 NTU, and most preferably at most 20 NTU.

[0491] In some preferred embodiments of the present invention, the beverage, for example in the form of a sports drink, comprises: a total amount of protein in the range of 0.5 to 15% w / w by weight of the beverage, more preferably in the range of 1 to 10% w / w by weight of the beverage, even more preferably in the range of 2 to 9% w / w by weight of the beverage, and most preferably in the range of 3 to 8% w / w by weight of the beverage, a total carbohydrate content of at most 75% of the total energy content (E%) of said beverage, more preferably at most 40E%, even more preferably at most 10E%, and most preferably at most 5E%; and A total lipid content of at most 10E%, more preferably at most 6E%, even more preferably at most 3E%, and most preferably at most 1E%.

[0492] In another preferred embodiment of the invention, the beverage, for example in the form of a low sugar sports drink, comprises: a total amount of protein in the range of 0.5 to 15% w / w by weight of the beverage, more preferably in the range of 1 to 10% w / w by weight of the beverage, even more preferably in the range of 2 to 9% by weight of the beverage, and most preferably in the range of 3 to 8% w / w by weight of the beverage, a total carbohydrate content of at most 10E%, more preferably at most 6E%, even more preferably at most 3E%, and most preferably at most 1E%, a total lipid content of at most 5E%, more preferably at most 4E%, even more preferably at most 3E% and most preferably at most 1E%, and A total amount of HIS in the range of 0.001-2% w / w, more preferably in the range of 0.005-1% w / w, and most preferably in the range of 0.01-0.5% w / w.

[0493] In another preferred embodiment of the invention, the filled heat treated beverage, for example in the form of a nutritionally complete beverage, comprises: a total amount of protein in the range of 0.5 to 15% w / w by weight of the beverage, more preferably in the range of 1 to 10% w / w by weight of the beverage, even more preferably in the range of 2 to 9% w / w by weight of the beverage, and most preferably in the range of 3 to 8% w / w by weight of the beverage, a total carbohydrate content in the range of 30-60% and most preferably in the range of 35-50E% of the total energy content of the beverage; and A total fat content in the range of 20-50% of the total energy content, more preferably in the range of 25-45E% and most preferably in the range of 30-40E%.

[0494] In some preferred embodiments of the present invention, the heat-treated beverage has a pH in the range of 6.2 to 7.5, most preferably a pH in the range of 6.8 to 7.5; Also includes: a total amount of protein in the range of 0.5 to 15% w / w by weight of the beverage, more preferably in the range of 1 to 10% w / w by weight of the beverage, even more preferably in the range of 2 to 9% w / w by weight of the beverage, and most preferably in the range of 3 to 8% w / w by weight of the beverage, and wherein the protein of the oxidized whey protein composition provides at least 50% w / w of the total protein of the heat-treated beverage, more preferably at least 70% w / w of the total protein of the heat-treated beverage, even more preferably at least 90% w / w of the total protein of the heat-treated beverage, and most preferably 100% w / w of the total protein of the heat-treated beverage.

[0495] In another preferred embodiment of the present invention, the heat-treated beverage has a pH in the range of 6.2 to 7.5, most preferably in the range of 6.8 to 7.5; Also includes: a total amount of protein in the range of 4 to 15% w / w by weight of the beverage, more preferably in the range of 5 to 14% w / w by weight of the beverage, even more preferably in the range of 6 to 13% w / w by weight of the beverage, and most preferably in the range of 8 to 12% w / w by weight of the beverage, and wherein the protein of the oxidized whey protein composition provides at least 50% w / w of the total protein of the heat-treated beverage, more preferably at least 70% w / w of the total protein of the heat-treated beverage, even more preferably at least 90% w / w of the total protein of the heat-treated beverage, and most preferably 100% w / w of the total protein of the heat-treated beverage.

[0496] The carbohydrate and fat content of the heat treated beverage may vary depending on the application.

[0497] In some preferred embodiments of the present invention, the heat treated beverage, for example in the form of a sports drink, comprises: a total carbohydrate content of at most 75% of the total energy content (E%) of said beverage, more preferably at most 40E%, even more preferably at most 10E%, even more preferably at most 5E%, and most preferably at most 1E%, and A total lipid content of at most 10E%, more preferably at most 6E%, even more preferably at most 3E%, and most preferably at most 1E%.

[0498] In another preferred embodiment of the invention, the filled heat treated beverage, for example in the form of a nutritionally complete beverage, comprises: a total carbohydrate content in the range of 30-60% and most preferably in the range of 35-50E% of the total energy content of the beverage; and A total amount of lipids in the range of 20-50%, more preferably 25-45E% and most preferably 30-40E% of said total energy content.

[0499] Said food product, and in particular said heat treated beverage, is preferably obtainable by the process of the present invention.

[0500] Yet another aspect of the present invention relates to a food composition comprising: a solid of the oxidized whey protein composition described herein, and one or more ingredients, preferably selected from the following: dairy ingredients, preferably non-oxidized dairy ingredients; Plant-derived ingredients, Non-dairy carbohydrate sources, Flavoring agents, and / or · Sweeteners (sweet carbohydrates / polyols / HIS).

[0501] Further details regarding the food ingredients are described in the following sequential embodiments.

[0502] Yet another aspect of the present invention relates to the use of an oxidized whey protein composition, preferably an oxidized whey protein composition of the present invention as a food ingredient, having a pH in the range of 5.5 to 8.5, preferably having a whey protein content of at least 3% w / w and preferably for improving the odour and / or reducing the level of unpleasant odour similar to rotten egg odour, of a heat sterilised beverage, preferably heat sterilised using an indirect heat treatment.

[0503] Certain particularly preferred embodiments of the present invention are described in the following sequentially numbered embodiments. [Serial number embodiment 1] A method for producing an oxidized whey protein composition comprising: (a) treating a whey protein source to provide a whey protein solution to be oxidized, The whey protein solution to be oxidized is Contains an oxidizing agent capable of oxidizing the thiol group of cysteine, and pH in the range of 6.5 to 9.5, a total protein content of at least 1% w / w based on the weight of the whey protein solution to be oxidized, A beta-lactoglobulin (BLG) content of at least 10% w / w of total protein; a protein content, preferably of at least 30% w / w based on total solids; a total fat content, preferably up to 3% w / w based on total solids; having; and wherein the oxidized whey protein solution further comprises: (i) having a temperature in the range of 0 to 160°C; and / or (ii) pressurized to a pressure in the range of 20 to 4000 bar; processing a whey protein source; (b) incubating the whey protein solution to be oxidized under one or more conditions capable of oxidizing at least a portion of the free thiols of the BLG molecules of the whey protein solution to be oxidized, preferably with the aim of reducing the amount of free thiol groups of the whey protein solution to be oxidized to a maximum of 15 micromoles per gram of protein, wherein the one or more conditions are (I) the whey protein solution to be oxidized has a temperature in the range of 0 to 160°C; and / or (II) pressurizing the whey protein solution to be oxidized to a pressure in the range of 20 to 4000 bar; incubating the whey protein solution to be oxidized; (c) optionally, and more preferably, subjecting the oxidized whey protein solution or protein concentrate thereof obtained in step (b) to a heat treatment step comprising heating to a temperature of at least 60°C; (d) optionally, and more preferably, drying the protein-containing liquid material derived from at least the oxidized whey protein solution obtained in step (b); The method comprises steps (a) to (d). [Serial Number 1a] 1. A method for producing an oxidized whey protein composition, the method comprising: (a) treating a whey protein source to provide a whey protein solution to be oxidized, The whey protein solution to be oxidized is Contains an oxidizing agent capable of oxidizing the thiol group of cysteine, and pH in the range of 6.5 to 9.5, a total protein content of at least 1% w / w based on the weight of the whey protein solution to be oxidized, A beta-lactoglobulin (BLG) content of at least 10% w / w of total protein; a protein content, preferably of at least 30% w / w based on total solids; a total fat content, preferably up to 3% w / w based on total solids; having; and wherein the oxidized whey protein solution further comprises: (i) having a temperature in the range of 0 to 65°C; and / or (ii) pressurized to a pressure in the range of 100 to 4000 bar; processing a whey protein source; (b) incubating the whey protein solution to be oxidized under one or more conditions capable of oxidizing at least a portion of the free thiols of the BLG molecules of the whey protein solution to be oxidized, preferably with the aim of reducing the amount of free thiol groups of the whey protein solution to be oxidized to a maximum of 15 micromoles per gram of protein, wherein the one or more conditions are: (I) the whey protein solution to be oxidized has a temperature in the range of 0 to 65°C; and / or (II) pressurizing the whey protein solution to be oxidized to a pressure in the range of 100 to 4000 bar; incubating the whey protein solution to be oxidized; (c) optionally, and more preferably, subjecting the oxidized whey protein solution or protein concentrate thereof obtained in step (b) to a heat treatment step comprising heating to a temperature of at least 60°C; (d) optionally, and more preferably, drying the protein-containing liquid material derived from at least the oxidized whey protein solution obtained in step (b); The method comprises steps (a) to (d). [Serial Number Implementation 2] The method according to serial embodiment 1, wherein the oxidizing agent capable of oxidizing a thiol group of cysteine ​​comprises or consists of peroxide, ozone, dioxygen, or a combination thereof. [Serial Number 3] The method according to any of the preceding serial embodiments, wherein the oxidizing agent capable of oxidizing a thiol group of cysteine ​​is a peroxide selected from the group consisting of hydrogen peroxide, benzoyl peroxide, and mixtures thereof. [Serial number embodiment 4] The method according to any of the preceding serial embodiments, wherein the oxidant is generated electrochemically. [Serial Number 5] A method according to any of the preceding sequential embodiments, wherein the oxidizing agent is generated enzymatically. [Serial Number 6] A method according to any of the preceding serial embodiments, wherein the whey protein solution to be oxidized in step (a) an oxidizing agent capable of oxidizing the thiol group of cysteine; and Total amount of free thiol groups, is at least 1:2, more preferably at least 1:1, even more preferably at least 2:1, and most preferably at least 3:1. [Serial Number 7] A method according to any of the preceding serial embodiments, wherein the whey protein solution to be oxidized in step (a) an oxidizing agent capable of oxidizing the thiol group of cysteine; and Total amount of free thiol groups, is from 1:2 to 200:1, more preferably from 1:2 to 100:1, even more preferably from 1:1 to 30:1, and most preferably from 1:1 to 15:1. [Serial Number 8] A method according to any of the preceding sequential embodiments, wherein the pH of the whey protein solution to be oxidized in step (a) is in the range of 7.0 to 9.5, more preferably 7.1 to 8.5, even more preferably 7.2 to 8.5, and most preferably 7.4 to 8.2. [Serial Number 9] A method according to any of the preceding sequential embodiments, wherein the pH of the whey protein solution to be oxidized in step (a) is in the range of 6.5 to 8.5, more preferably 6.6 to 8.0, even more preferably 6.7 to 7.5, and most preferably 6.8 to 7.3. [Serial Number 10] A method according to any of the preceding serial embodiments, wherein the total protein content of the oxidized whey protein solution in step (a) is at least 2% w / w, more preferably at least 3% w / w, even more preferably at least 5% w / w, and most preferably at least 6% w / w of the weight of the oxidized whey protein solution. [Serial Number 11] A method according to any of the preceding sequential embodiments, wherein the total protein content of the oxidized whey protein solution in step (a) is in the range from 1 to 30% w / w, more preferably from 3 to 20% w / w, even more preferably from 4 to 15% w / w, and most preferably at least 6 to 10% w / w, based on the weight of the oxidized whey protein solution. [Serial Number 12] A process according to any of the preceding sequential embodiments, wherein the total protein content of the oxidized whey protein solution in step (a) is in the range from 1 to 12% w / w, more preferably from 3 to 11% w / w, even more preferably from 4 to 10% w / w, and most preferably from 5 to 9% w / w, based on the weight of the oxidized whey protein solution. [Serial Number 13a] A method according to any of the preceding serial embodiments, wherein the total protein content of the oxidized whey protein solution in step (a) is at least 30% w / w, based on the total solids of the oxidized whey protein solution, more preferably at least 50% w / w, even more preferably at least 75% w / w, and most preferably at least 85% w / w, based on the total solids of the oxidized whey protein solution. [Serial Number 13b] A method according to any of the preceding sequential embodiments, wherein the total protein content of the oxidized whey protein solution in step (a) is in the range of 30-99% w / w based on the total solids of the oxidized whey protein solution, more preferably 50-97% w / w, even more preferably 75-96% w / w, and most preferably in the range of at least 85-95% w / w based on the total solids of the oxidized whey protein solution. [Serial Number 14] A method according to any of the preceding serial embodiments, wherein the BLG content of the oxidized whey protein solution in step (a) is at least 20% w / w based on the total protein of the oxidized whey protein solution, more preferably at least 40% w / w, even more preferably at least 45% w / w, and most preferably at least 50% w / w based on the total protein of the oxidized whey protein solution. [Serial Number 15] A method according to any of the preceding serial embodiments, wherein the BLG content of the oxidized whey protein solution in step (a) is at least 55% w / w based on the total protein of the oxidized whey protein solution, more preferably at least 60% w / w, even more preferably at least 80% w / w, and most preferably at least 90% w / w based on the total protein of the oxidized whey protein solution. [Serial Number 16] A method according to any of the preceding sequential embodiments, wherein the BLG content of the oxidized whey protein solution in step (a) is in the range of 10-99% w / w based on the total protein of the oxidized whey protein solution, more preferably 45-98% w / w, even more preferably 80-96% w / w, and most preferably 90-95% w / w based on the total protein of the oxidized whey protein solution. [Serial Number 17] A method according to any of the preceding sequential embodiments, wherein the BLG content of the oxidized whey protein solution in step (a) is in the range of 10-90% w / w based on the total protein of the oxidized whey protein solution, more preferably 20-80% w / w, even more preferably 30-75% w / w, and most preferably 45-70% w / w based on the total protein of the oxidized whey protein solution. [Serial Number 18] A process according to any of the preceding serial embodiments, wherein the total fat content of the oxidized whey protein solution of step (a) is at most 1% w / w of total solids, more preferably at most 0.5% w / w, even more preferably at most 0.2% w / w, and most preferably at most 0.1% w / w of total solids. [Serial Number 19] A process according to any of the preceding sequential embodiments, wherein condition (i) comprises that the temperature of the whey protein solution to be oxidized in step (a) is in the range of 5 to 65°C, more preferably in the range of 10 to 65°C, even more preferably in the range of 30 to 60°C, and most preferably in the range of 40 to 55°C. [Serial Number 19a] A process according to any of the preceding sequential embodiments, wherein condition (i) comprises that the temperature of the whey protein solution to be oxidized in step (a) is in the range of 66 to 160°C, more preferably 70 to 145°C, even more preferably 75 to 120°C, and most preferably 80 to 100°C. [Serial Number 20] A process according to any of the preceding sequential embodiments, wherein condition (ii) comprises that the whey protein solution to be oxidized in step (a) is pressurized to a pressure in the range of from 100 to 4000 bar, more preferably from 200 to 3500 bar, even more preferably from 300 to 3000 bar, and most preferably from 500 to 2500 bar. [Serial Number Embodiment 20a] A process according to any of the preceding sequential embodiments, wherein condition (ii) comprises that the whey protein solution to be oxidized in step (a) is pressurized to a pressure in the range from 25 to 1000 bar, more preferably from 30 to 500 bar, even more preferably from 35 to 300 bar, and most preferably from 40 to 200 bar. [Serial Number 21] A method according to any of the preceding sequential embodiments, wherein step (a) comprises condition (i). [Serial Number 22] A method according to any of the preceding sequential embodiments, wherein step (a) comprises condition (ii). [Serial Number 23] A method according to any of the preceding serial embodiments, wherein step (a) includes both features (i) and (ii). [Serial Number 24] A method according to any of the preceding serial embodiments, wherein the treating of the whey protein source in step (a) comprises: (I) contacting, preferably by combining or mixing, said whey protein source with an oxidizing agent capable of oxidizing at least the thiols of cysteine, and optionally further ingredients; (II) adjusting the pH, if necessary, to a pH in the range of 6.5 to 9.5; (III) optionally pressurizing to a pressure in the range of 20 to 4000 bar; (IV) optionally adjusting the temperature to a temperature in the range of 0 to 160°C; A method comprising: [Serial Number 24a] A method according to any of the preceding serial embodiments, wherein the treating of the whey protein source in step (a) comprises: (I) contacting, preferably by combining or mixing, said whey protein source with an oxidizing agent capable of oxidizing at least the thiols of cysteine, and optionally further ingredients; (II) adjusting the pH, if necessary, to a pH in the range of 6.5 to 9.5; (III) optionally pressurizing to a pressure in the range of 100 to 4000 bar; (IV) optionally adjusting the temperature to a temperature in the range of 0 to 65°C; A method comprising: [Serial Number 25] A method according to any of the preceding sequential embodiments, wherein step (b) is carried out such that the initial amount of free thiol groups in the oxidized whey protein solution of step (a) is reduced or reduced to at most 80% of the initial amount, more preferably at most 76%, even more preferably at most 73%, and most preferably at most 70% of the initial amount. [Serial Number 26] A method according to any of the preceding sequential embodiments, wherein step (b) is carried out to reduce or such that the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a) is reduced to 20-80% of the initial amount, more preferably to 30-80%, even more preferably to 50-75%, and most preferably to 60-75% of the initial amount. [Serial Number 27] A method according to any of the preceding sequential embodiments, wherein step (b) is carried out such that the initial amount of free thiol groups in the oxidized whey protein solution of step (a) is reduced or decreased by at most 30% of the initial amount, more preferably at most 25%, even more preferably at most 20%, and most preferably at most 15% of the initial amount. [Serial Number 28] A method according to any of the preceding sequential embodiments, wherein step (b) is carried out such that the initial amount of free thiol groups in the oxidized whey protein solution of step (a) is reduced or decreased to a maximum of 10% of the initial amount, more preferably to a maximum of 5%, even more preferably to a maximum of 3%, and most preferably to a maximum of 1% of the initial amount. [Serial Number 29] A method according to any of the preceding sequential embodiments, wherein step (b) is carried out to reduce, or such that the amount of free thiol groups in the whey protein solution to be oxidized in step (a) is reduced from its initial amount to 0.01-30% of the initial amount, more preferably 0.02-25%, even more preferably 0.05-20%, and most preferably 0.1-10% of the initial amount. [Serial Number 30] A method according to any of the preceding serial embodiments, wherein step (b) reduces, or is carried out so as to reduce, the amount of free thiol in the whey protein solution to be oxidized to at most 10 micromoles per gram of protein, more preferably at most 8 micromoles per gram of protein, more preferably at most 5 micromoles per gram of protein, even more preferably at most 3 micromoles per gram of protein, and most preferably at most 2 micromoles per gram of protein. [Serial Number 31] A method according to any of the preceding serial embodiments, wherein step (b) reduces, or is carried out so as to reduce, the amount of free thiol in the whey protein solution to be oxidized to at most 1 micromoles per gram of protein, more preferably at most 0.7 micromoles per gram of protein, even more preferably at most 0.5 micromoles per gram of protein, and most preferably at most 0.2 micromoles per gram of protein. [Serial Number 32] A process according to any of the preceding sequential embodiments, wherein step (b) comprises adjusting the pH during oxidation to a pH in the range of from 6.5 to 9.5, more preferably from 7.0 to 8.5, even more preferably from 7.2 to 8.5, and most preferably from 7.5 to 8.5. [Serial Number 33] A method according to any of the preceding serial numbered embodiments, comprising: The amount of oxidant consumed in step (b) (excluding the amount of excess oxidant removed at the end of step (b)). and the initial amount of free thiol groups in step (a), is a molar ratio between 1:2 to 30:1, more preferably 1:2 to 25:1, even more preferably 1:1 to 20:1, and most preferably 1:1 to 15:1. [Serial Number 34] A method according to any of the preceding serial numbered embodiments, comprising: the amount of oxidizing agent capable of oxidizing the thiol groups of cysteines consumed in step (b), excluding the amount of excess oxidizing agent removed at the end of step (b); and the initial amount of free thiol groups in step (a), is from 2:1 to 30:1, more preferably from 3:1 to 25:1, even more preferably from 4:1 to 20:1, and most preferably from 5:1 to 15:1; method. [Serial Number 35] A method according to any of the preceding serial numbered embodiments, comprising: where the amount of oxidizing agent capable of oxidizing the thiol groups of cysteines consumed in step (b), excluding the amount of excess oxidizing agent removed at the end of step (b); and the initial amount of free thiol groups in step (a), is 1:4 to 15:1, more preferably 1:3 to 10:1, even more preferably 1:2 to 5:1, and most preferably 1:2 to 2:1; method. [Serial Number 36] A process according to any of the preceding sequential embodiments, wherein the process does not include the addition of sulfites and / or does not include sulfitolysis. [Serial Number 37] A process according to any of the preceding sequential embodiments, wherein the one or more conditions of step (b) comprise: (I) the oxidizing whey protein solution having a temperature in the range of from 5 to 65°C, more preferably from 10 to 65°C, even more preferably from 30 to 60°C, and most preferably from 40 to 60°C. [Serial Number 37a] A process according to any of the preceding sequential embodiments, wherein the one or more conditions of step (b) comprise: (I) oxidizing the whey protein solution having a temperature in the range of 66 to 160°C, more preferably 70 to 145°C, even more preferably 75 to 120°C, and most preferably 80 to 100°C. [Serial Number 38] A method according to any of the preceding sequential embodiments, wherein the temperature of the whey protein solution to be oxidized in step (b) is maintained within a desired temperature range for a time sufficient to reduce the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a) to at most 80% of said initial amount, more preferably at most 76% of said initial amount, even more preferably at most 73% of said initial amount, and most preferably at most 70% of said initial amount. [Serial Number 39] A method according to any of the preceding sequential embodiments, wherein the temperature of the whey protein solution to be oxidized in step (b) is maintained within a desired temperature range for a time sufficient to reduce the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a) to 20-80% of the initial amount, more preferably 30-80%, even more preferably 50-75%, and most preferably 60-75% of the initial amount. [Serial Number 40] A method according to serial embodiment 38, wherein the temperature of the whey protein solution to be oxidized in step (b) is maintained within a desired temperature range for a time sufficient to reduce the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a) to at most 30% of the initial amount, more preferably at most 25%, even more preferably at most 20%, and most preferably at most 15% of the initial amount. [Serial Number 41] A process according to any of the preceding sequential embodiments, wherein (II) the conditions of step (b) include pressurizing the whey protein solution to be oxidized to a pressure in the range of from 100 to 4000 bar, more preferably from 200 to 3500 bar, even more preferably from 300 to 3000 bar, and most preferably from 500 to 2500 bar. [Serial Number Implementation Example 41a] A process according to any of the preceding sequential embodiments, wherein (II) the conditions of step (b) include pressurizing the whey protein solution to be oxidized to a pressure in the range of from 25 to 1000 bar, more preferably from 30 to 500 bar, even more preferably from 35 to 300 bar, and most preferably from 40 to 200 bar. [Serial Number 42] A method according to any of the preceding sequential embodiments, wherein the pressure of the whey protein solution to be oxidized in step (b) is maintained within a desired pressure range for a time sufficient to reduce the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a) to at most 80% of the initial amount, more preferably at most 76% of the initial amount, even more preferably at most 73% of the initial amount, and most preferably at most 70% of the initial amount. [Serial Number 43] A method according to any of the preceding sequential embodiments, wherein the pressure of the whey protein solution to be oxidized in step (b) is maintained within a desired pressure range for a time sufficient to reduce the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a) to between 20 and 80% of the initial amount, more preferably between 30 and 80%, even more preferably between 50 and 75%, and most preferably between 60 and 75% of the initial amount. [Serial Number 44] A method according to serial embodiment 42, wherein pressure is applied to the whey protein solution to be oxidized in step (b) for a time sufficient to reduce the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a) to at most 30% of the initial amount, more preferably at most 25% of the initial amount, even more preferably at most 20%, and most preferably at most 15%. [Serial Number 45] A method according to any of the preceding serial embodiments, wherein step (b) comprises increasing the temperature of the whey protein solution to be oxidized in step (b) to the maximum oxidation temperature at a heating rate of at most 2°C / min, more preferably at most 1°C / min, even more preferably at most 0.3°C / min and most preferably at most 0.1°C / min. [Serial Number 46] The method according to any of the preceding sequential embodiments, wherein step (b) does not comprise further adding or generating an oxidizing agent capable of oxidizing a thiol group of a cysteine ​​in step (b). [Serial Number 47] The method according to any of the preceding sequential embodiments, wherein step (b) further comprises adding or generating an oxidizing agent capable of oxidizing a thiol group of cysteine ​​in step (b). [Serial Number 48] A process according to any of the preceding sequential embodiments, wherein the time taken for step (b) is at most 48 hours, more preferably at most 36 hours, even more preferably at most 30 hours, and most preferably at most 25 hours. [Serial Number 49] A process according to any of the preceding sequential embodiments, wherein the time taken for step (b) is from 0.1 to 48 hours, more preferably from 3 to 36 hours, even more preferably from 5 to 30 hours, and most preferably from 10 to 25 hours. [Serial Number 50] A method according to any of the preceding sequential embodiments, wherein the time taken for step (b) is up to 12 hours, more preferably up to 6 hours, even more preferably up to 3 hours, and most preferably up to 1 hour. [Serial Number Embodiment 50a] A method according to any of the preceding sequential embodiments, wherein the time taken for step (b) is at most 10 minutes, more preferably at most 6 minutes, even more preferably at most 3 minutes, and most preferably at most 2 minutes. [Serial Number 51] A process according to any of the preceding sequential embodiments, wherein the time required for step (b) is from 0.1 to 12 hours, more preferably from 0.1 to 6 hours, even more preferably from 0.1 to 3 hours, and most preferably from 0.1 to 1 hour. [Serial Number 51a] A method according to any of the preceding sequential embodiments, wherein the time taken for step (b) is from 0.1 seconds to 10 minutes, more preferably from 1 second to 6 minutes, even more preferably from 5 seconds to 3 minutes, and most preferably from 10 seconds to 2 minutes. [Serial Number 52] A method according to any of the preceding sequential embodiments, wherein step (b) comprises allowing the oxidation to proceed until substantially all of the oxidizing agent capable of oxidizing cysteine ​​thiol groups is used up. [Serial Number 53] A method according to any of the preceding sequential embodiments, wherein step (b) comprises terminating the oxidation by contacting the whey protein solution to be oxidized with a component, preferably catalase, which removes residual oxidizing agent capable of oxidizing cysteine ​​thiol groups. [Serial Number 54] A method according to any of the preceding serial embodiments, further comprising a step (c) comprising subjecting the oxidized whey protein solution obtained in step (b) to a heat treatment step. [Serial Number 55] A method according to any of the preceding serial embodiments, further comprising the step (d) of drying the liquid material comprising at least proteins derived from the oxidized whey protein solution obtained in step (b). [Serial Number 56] 1. An oxidized whey protein composition comprising: A protein content of at least 30% w / w of total solids; a fat content preferably of maximum 3% w / w based on total solids; Up to 15 micromoles of free thiol groups per gram of protein; a tryptophan content, preferably of at least 0.7% w / w based on total protein; a methionine content preferably of at least 0.3% w / w based on total protein; preferably a kynurenine content of up to 0.2 micrograms per mg of protein; a content of protein-bound sulfur preferably in the range of 100 to 600 micromoles per gram of protein, and a content of protein-bound cysteine ​​residues forming disulfide bonds preferably in the range of 150-400 micromoles per gram of protein; 1. An oxidized whey protein composition comprising: [Serial Number 57] An oxidized whey protein composition according to serial numbered embodiment 56, obtainable by oxidation of a whey protein source as described herein, preferably by a method according to one or more of serial numbered embodiments 1 to 49. [Serial Number 58] An oxidized whey protein composition according to any of the serial embodiments 56 to 57, which is in liquid or solid form, preferably in powder form. [Serial Number 59] A process for producing a food product; treating the oxidized whey protein composition; and / or combining an oxidized whey protein composition or a processed oxidized whey protein composition according to any one or more of serial embodiments 56 to 58 with one or more further ingredients, and optionally treating the combination; The process includes: [Serial Number 60] 1. A process for producing a heat treated, preferably heat sterilized, beverage having a pH of 5.5 to 8.5, more preferably a pH of 6.5 to 7.5, comprising: (1) combining an oxidized whey protein composition with one or more further ingredients according to one or more of the serial embodiments 50 to 52 to obtain a liquid mixture having a pH of 5.5 to 8.5, wherein the liquid mixture comprises: a sufficient amount of the oxidized whey protein composition to contribute at least 0.5% w / w protein; Preferably, sweeteners and / or flavouring agents, and · Water, Including, The combining step, (2) filling the liquid mixture into a container; Includes; wherein the liquid mixture is subjected to heat sterilization before and / or after filling; process. [Serial Number 61] The process according to serial embodiment 60, wherein the liquid mixture contains, prior to heat sterilization, at most 60 micromoles of free thiol groups per 100 g of liquid mixture, more preferably at most 40 micromoles of free thiol groups per 100 g of liquid mixture, even more preferably at most 30 micromoles of free thiol groups per 100 g of liquid mixture, and most preferably at most 30 micromoles of free thiol groups per 100 g of liquid mixture. [Serial Number 62] The process according to serial embodiment 60 or 61, wherein the liquid mixture contains, prior to heat sterilization, at most 20 micromoles of free thiol groups per 100 g of liquid mixture, more preferably at most 15 micromoles of free thiol groups per 100 g of liquid mixture, even more preferably at most 10 micromoles of free thiol groups per 100 g of liquid mixture, and most preferably at most 5 micromoles of free thiol groups per 100 g of liquid mixture. [Serial Number 63] A food product comprising an oxidized whey protein composition according to any one or more of serial embodiments 56 to 58, preferably in an amount such that the oxidized whey protein composition contributes at least 0.5% w / w protein by weight of the food product. [Serial Number 64] A heat-treated, preferably heat-sterilized, beverage having a pH of 5.5 to 8.5, and more preferably a pH of 6.5 to 7.5, comprising an oxidized whey protein composition according to one or more of serial embodiments 56 to 58 in an amount sufficient to contribute at least 0.5% w / w protein. [Serial Number 65] A heat-treated, preferably heat-sterilized, beverage according to serial embodiment 64, having an H2S content of up to 5 micromoles / L, more preferably 3 micromoles / L, even more preferably 1.0 micromoles / L, and most preferably up to 0.7 micromoles / L. [Serial Number 66] A heat-treated, preferably heat-sterilized, beverage according to serial embodiment 64 or 65, having an H2S content of at most 5 micromoles / L, more preferably 3 micromoles / L, even more preferably 1.0 micromoles / L, and most preferably at most 0.7 micromoles / L, one hour after production. [Serial Number 67] A heat-treated, preferably heat-sterilized, beverage according to any of serial embodiments 64-66, having an H2S content of up to 5 micromoles / L, more preferably 3 micromoles / L, even more preferably 1.0 micromoles / L, and most preferably up to 0.7 micromoles / L, 7 days after production. [Serial Number 68] A heat treated, preferably heat sterilized, beverage according to any of serial embodiments 64 to 67, comprising a total protein amount in the range of 0.5 to 15% w / w by weight of the beverage, more preferably in the range of 1 to 10% w / w by weight of the beverage, even more preferably in the range of 2 to 9% w / w by weight of the beverage, and most preferably in the range of 3 to 8% w / w by weight of the beverage. [Serial Number 69] A heat treated, preferably heat sterilized, beverage according to any of serial embodiments 64-68 comprises an oxidized whey protein composition according to one or more of serial embodiments 56-58 in an amount sufficient to contribute at least 30% w / w of the total protein of the heat treated beverage, more preferably at least 50% w / w of the total protein, even more preferably at least 70% w / w of the total protein, and most preferably at least 80% w / w of the total protein. [Serial Number 70] A heat treated, preferably heat sterilized, beverage according to any of serial embodiments 64-69 comprises an oxidized whey protein composition according to one or more of serial embodiments 56-58 in an amount sufficient to contribute at least 90% w / w of the total protein of the heat treated beverage, more preferably at least 95% w / w of the total protein, even more preferably at least 99% w / w of the total protein, and most preferably 100% w / w of the total protein. [Serial Number 71] A heat-treated, preferably heat-sterilized, beverage according to any of serial embodiments 64-70, comprising total protein in an amount of at least 50% w / w of total solids, more preferably at least 60% w / w of total solids, even more preferably at least 70% w / w of total solids, and most preferably at least 80% w / w of total solids. [Serial Number 72] A heat-treated, preferably heat-sterilized, beverage according to any of serial embodiments 64-71, comprising total protein in an amount of at least 80% w / w of total solids, more preferably at least 90% w / w of total solids, even more preferably at least 92% w / w of total solids, and most preferably at least 94% w / w of total solids. [Serial Number 73] A heat-treated, preferably heat-sterilized, beverage according to any of serial embodiments 64-72, having a solids content of 0.5-50% w / w, more preferably 1-35% w / w, even more preferably 2-20% w / w, and most preferably 3-10% w / w. [Serial Number 74] A food product according to any of serial numbered embodiments 63-73, obtainable according to a process according to one or more of serial numbered embodiments 60-62. [Serial Number 75] A food ingredient; a solid of an oxidized whey protein composition according to one or more of serial embodiments 56 to 58; and one or more ingredients, preferably: dairy ingredients, preferably non-oxidized dairy ingredients; Plant-derived ingredients, Non-dairy carbohydrate sources, Flavoring agents, and / or Sweeteners (sweet carbohydrates / polyols / HIS), An ingredient selected from A food ingredient, comprising: [Serial Number 76] A food ingredient according to serial numbered embodiment 75, wherein the one or more additional ingredients comprise a dairy component comprising one or more of micellar casein, non-oxidized whey protein, caseinomacropeptide, ultrafiltration permeate of milk or whey, denatured whey protein, and combinations thereof. [Serial Number 77] 77. The food ingredient according to serial embodiment 75 or 76, wherein the one or more further ingredients preferably comprise a plant-derived ingredient comprising one or more of soy protein, pea protein, plant-derived dietary fiber, and combinations thereof. [Serial Number 78] The food ingredient according to any one of serial embodiments 75 to 77, wherein the one or more further ingredients comprise a non-dairy carbohydrate source, preferably comprising one or more of sucrose, maltodextrin, non-dairy oligosaccharides, non-dairy polysaccharides. [Serial Number 79] The food ingredient according to any one of serial embodiments 75-78, wherein the one or more additional ingredients comprise a sweetener, preferably comprising one or more of a carbohydrate sweetener, a polyol, a high intensity sweetener, and combinations thereof. [Serial Number 80] A food composition according to any of serial embodiments 75 to 79, wherein the solids of an oxidized whey protein composition according to one or more of serial embodiments 56 to 58 contribute from 0.5 to 95% w / w of the weight of the food composition, more preferably from 1 to 90% w / w, even more preferably from 5 to 85% w / w, and most preferably from 10 to 80% w / w of the weight of the food composition. In the context of the present invention, the term "solids of the oxidized whey protein composition" relates to the solids (including proteins, carbohydrates, lipids, and minerals) remaining when all the water is removed from the oxidized whey protein composition. The "solids of the oxidized whey protein composition" may be provided, for example, by the oxidized whey protein composition in powder or liquid form. [Serial Number 81] A food composition according to any one of serial embodiments 75 to 80, wherein the solids of an oxidized whey protein composition according to one or more of serial embodiments 56 to 58 contribute from 0.5 to 60% w / w of the weight of the food composition, more preferably from 1 to 50% w / w, even more preferably from 5 to 40% w / w, and most preferably from 10 to 30% w / w of the weight of the food composition. [Serial Number 82] A food composition according to any one of serial embodiments 75 to 81, wherein the solids of an oxidized whey protein composition according to one or more of serial embodiments 56 to 58 contribute from 0.5 to 95% w / w of the protein of the food composition, more preferably from 1 to 90% w / w, even more preferably from 5 to 85% w / w, and most preferably from 10 to 80% w / w of the protein of the food composition. [Serial Number 83] A food composition according to any one of serial embodiments 75 to 82, wherein the solids of an oxidized whey protein composition according to any one or more of serial embodiments 56 to 58 contribute from 0.5 to 60% w / w of the protein of the food composition, more preferably from 1 to 50% w / w, even more preferably from 5 to 40% w / w, and most preferably from 10 to 30% w / w of the protein of the food composition. [Serial Number 84] A food ingredient according to any one of serial embodiments 75 to 83, comprising free thiol groups in an amount of at most 15 micromoles per gram of protein, more preferably at most 14 micromoles per gram of protein, even more preferably at most 13 micromoles per gram of protein, and most preferably at most 12 micromoles per gram of protein. [Serial Number 85] A food ingredient according to any one of serial embodiments 75 to 84, comprising free thiol groups in an amount of 0.001 to 15 micromoles per gram of protein, more preferably 0.01 to 14 micromoles per gram of protein, even more preferably 0.01 to 13 micromoles per gram of protein, and most preferably 0.01 to 12 micromoles per gram of protein. [Serial Number 86] A food ingredient according to any one of serial embodiments 75 to 85, comprising free thiol groups in an amount of at most 10 micromoles per gram of protein, more preferably at most 8 micromoles per gram of protein, more preferably at most 5 micromoles per gram of protein, even more preferably at most 3 micromoles per gram of protein, and most preferably at most 2 micromoles per gram of protein. [Serial Number 87] A food ingredient according to any one of serial embodiments 75 to 86, comprising free thiol groups in an amount of 0.01 to 10 micromoles per gram of protein, more preferably 0.01 to 8 micromoles per gram of protein, more preferably 0.01 to 5 micromoles per gram of protein, even more preferably 0.01 to 3 micromoles per gram of protein, and most preferably 0.01 to 2 micromoles per gram of protein. [Serial Number 88] A food ingredient according to any one of serial embodiments 75 to 87, preferably in liquid form using water as the primary solvent, and more preferably using water as the only solvent. [Serial Number 89] A food ingredient according to any one of serial embodiments 75 to 87, preferably in powder form containing water in an amount of up to 6% w / w. [Serial Number 90] A food ingredient according to serial numbered embodiment 89, comprising: A food ingredient, wherein the powder is in powder form prepared by dry mixing of an oxidized whey protein composition according to one or more of serial embodiments 56 to 58, together with one or more further ingredients in powder form. [Serial Number 91] A food ingredient according to serial numbered embodiment 89, comprising: A food ingredient wherein the powder is prepared by drying a liquid, preferably by spray drying, according to serial embodiment 88. [Serial Number 100] Use of an oxidized whey protein composition as a food ingredient, preferably an oxidized whey protein composition according to one or more of serial embodiments 56 to 58, in a heat sterilized beverage having a pH in the range of 5.5 to 8.5, preferably having a whey protein content of at least 3% w / w, and preferably heat sterilized using an indirect heat treatment, preferably to improve the odor and / or reduce an unpleasant odor similar to that of rotten eggs.

[0504] The present invention has been described above with reference to specific embodiments, however, other embodiments than those described above may equally fall within the scope of the present invention. Unless expressly stated otherwise, the different features and steps of the various embodiments and aspects of the invention may be combined in ways other than those described herein.

[0505] Working Example Analysis method Analysis A: Total Protein The total protein content (true protein) of a sample is determined by: (1) Determine the total nitrogen of the sample according to ISO 8968-1 / 2|IDF020-1 / 2-Milk-. Determination of nitrogen content - part 1 2: Determination of nitrogen content using the Kjeldahl method. (2) Determine the non-protein nitrogen of the sample according to ISO 8968-4 | IDF020-4-Milk-. Determination of nitrogen content – ​​part 4: Determination of protein nitrogen content. (3) (m total nitrogen - m non-protein nitrogen) * 6.38 The total protein amount is calculated as:

[0506] Analysis B: pH All pH values ​​are measured using a glass pH electrode and normalized to 25°C.

[0507] Glass pH electrodes (with temperature compensation) are carefully pre-rinsed and calibrated before use.

[0508] If the sample is in liquid form, the pH of the solution is measured directly and normalized to 25°C.

[0509] If the sample is a powder, 10 grams of powder are dissolved in 90 ml of demineralized water at room temperature with vigorous stirring. The pH of the solution is then measured and normalized to 25°C.

[0510] Analysis C: Viscosity The viscosity was estimated at 22°C using Gilson's Viscoman and was approximately 300 s -1 The shear rate is reported as

[0511] Analysis D: Quantification of H2S using an H2S sensor The levels of H2S were measured by a microsensor (SULF-NPLR, needle type, Unisense A / S, Denmark) coupled to a single channel amplifier (Monometter-9514, Unisense A / S, Denmark). The acquired H2S signal, expressed in millivolts, can be used as an indicator of the H2S level in the sample and is recorded by the "LOGGER" software provided by Unisense A / S. The microsensor was calibrated the day before each use using a H2S calibration kit provided by the manufacturer (Calkit-H2S, Unisense A / S, Denmark). The highest concentration of H2S in the calibration kit was further diluted 10-fold according to section 7 of the manual (November 2020 version, Unisense A / S). The concentration of H2S can be automatically converted to μM by the software.

[0512] To measure the simulated UHT or pilot scale UHT samples, the samples were equilibrated at 20°C for 30 minutes and the sensor needle was inserted into the liquid phase of the sample by piercing the silicone seal. Three replicates were performed for each sample.

[0513] Analysis E: Free and total thiol groups The free thiol content and total thiol content in whey protein samples were quantified using the same method and equipment as described by Kurz et al. (2020). The free thiol (SH) content in the samples is reported in micromoles per gram of protein, with the protein content typically determined by the Total Protein method in Analysis A. Kurz, F., Hengst, C., & Kulozik, U. (2020). RP-HPLC method for simultaneous determination of free and total thiol groups in native and heat-aggregated whey proteins. Method X, 101112.

[0514] Analysis F1: Amino acid quantification Amino acids were quantified as described in Zainudin MAM, Poojary MM, Jongberg S, Lund MN, "Light exposure accelerates oxidative protein polymerization in beef stored in high oxygen atmosphere," Food Chem. 299 (2019) 125132.

[0515] All samples were frozen at −80°C immediately after preparation, transferred onto dry ice and kept at −80°C until analysis.

[0516] 0.5 mg of protein was hydrolyzed with degassed 4 M methanesulfonic acid (containing 0.2% w / v tryptamine) in a PICO TAG hydrolysis vial at 110° C. for 17 hours and 30 minutes under vacuum.

[0517] The neutralized dried hydrolysate was mixed with aminocaproic acid (internal standard) and derivatized with o-phthalaldehyde / 3-mercaptopropionic acid and fluorenylmethyloxycarbonyl chloride. The derivatized amino acids were analyzed using a UHPLC-FLD system equipped with an Agilent AdvanceBio AAA column. Quantification of each amino acid (internal standard calibration) was performed based on an 8-point calibration curve generated using true standards.

[0518] Analysis F2: Quantitation of amino acid oxidation Protein oxidation was measured by a method described by Mahesha M. Poojary, Brijesh K. Tiwari, and Marianne N. Lund ("Selective and sensitive UHPLC-ESI-Orbitrap MS method to quantify protein oxidation markers"; Talanta, Vol. 234 (2021), 122700).

[0519] All samples assayed were frozen at -80°C immediately after preparation, transferred onto dry ice and kept at -80°C until analysis.

[0520] 0.5 mg of protein was hydrolyzed with degassed 4 M methanesulfonic acid (containing 0.2% w / v tryptamine) in a PICO TAG hydrolysis vial at 110° C. for 17 hours and 30 minutes under vacuum.

[0521] The neutralized dried hydrolysates were mixed with 5-methyltryptophan (internal standard) and analyzed using a UHPLC-FLD system equipped with a Waters Aquity HSS T3 column.

[0522] Quantification of each amino acid (internal standard calibration) was performed based on an eight-point calibration curve constructed using authentic standards.

[0523] Analysis G: Determination of molecular weight and intrinsic viscosity after oxidation by GPC analysis The molecular weights of protein species in the whey protein samples were analyzed by size exclusion chromatography using a SEC-MALS-IV-RI HPLC system consisting essentially of a Thermo ISO 3100SD pump, a WPS-3000TSL autosampler and a Refractomax 521 refractive index detector. The system was further equipped with a Wyatt miniDawn TREOS II light scattering detector and a WYATT VISCOSTAR online viscometer.

[0524] All samples were diluted to 1% protein in eluent (10 mM phosphate, 30 mM NaCl (pH 7.0) and 0.1% poroclean) and 10 μl was separated using 1x Bio-SEC-5 guard + 2x300Å BioSEC-5 at 0.75 ml / min in eluent. This instrument gives good results within 10% of the αLA, BLG and BSA standards.

[0525] Data Analysis: Weight average molecular weight and weight average intrinsic viscosity were determined using Astra software [v7.3.2.19] by integrating all signals eluting before the void volume, i.e., signals for both monomers and oligomers and larger aggregate species.

[0526] Analysis H: Evaluation of residual hydrogen peroxide Residual hydrogen peroxide was measured by quantitative colorimetric analysis using a SYNERGY MX microplate reader; measurements were performed as described by the manufacturer (ABCAM AB102500 Hydrogen Peroxide Assay Kit (Colorimetric / Fluorometric; Version 6; last updated January 8, 2019).

[0527] To ensure that the concentration of residual H2O2 in the 50 μl samples was within the linear range of the assay (i.e., 0–5 nmol H2O2 per well; H2O2 standards provided in the assay kit were used), all samples were diluted with 10 mM phosphate (pH 7.0) relative to the amount of H2O2 initially added.

[0528] A calibration curve containing 0–5 nmol H2O2 per well was generated using H2O2 standards provided with the assay kit according to the manufacturer's instructions.

[0529] The concentration of H2O2 in the samples was determined by a calibration curve and sample dilution.

[0530] Analysis I: Determination of non-reducing lanthionine and lysinoalanine cross-links in whey protein samples The amount of lanthionine in WPI samples was determined using a modified method as described in Mahesha M. Poojary et al., "Liquid chromatography quadrupole-Orbitrap mass spectrometry for the simultaneous analysis of advanced glycation end products and protein-derived cross-links in food and biological matrices," Journal of Chromatography A, Vol. 1615, 2020, using columns and solvents from Analysis F2.

[0531] All samples analyzed by Analysis I were frozen at −80°C immediately after preparation, transferred onto dry ice and kept at −80°C until analysis.

[0532] Briefly, samples corresponding to 0.5 mg of protein were hydrolyzed with degassed 6 M hydrochloric acid (containing thioglycolic acid) in PICO TAG hydrolysis vials at 110° C. for 22 hours under vacuum.

[0533] The dried hydrolysates were mixed with lysine-d4 (internal standard) and analyzed using an LC-MS system equipped with a Waters Aquity HSS T3 column. Quantification of LAL and LAN (internal standard calibration) was performed based on an 8-point calibration curve generated with authentic standards.

[0534] Analysis J: Evaluation of non-H2S odors from heat-treated samples Whey protein beverages were analyzed for non-H2S odors using dynamic headspace sampling techniques coupled with gas chromatographic separation and mass spectrometry identification. All non-H2S odors in the beverages were measured in triplicate.

[0535] The above samples were subjected to UHT treatment (ultra-high temperature treatment) as described in Example 1, and the H2S content was determined according to Analysis D. Samples were removed from the heat treatment vials and 5 mL of the sample was transferred to a 100 mL blue cap flask. 1.5 μL of 100 ppm 2-hexanone-5-methyl internal standard solution was added to give a final concentration of 30 ppb.

[0536] The bottles were fitted with sorbent traps (Tenax TA / Graphitized Carbon / Carboxen 1000, Restek Corp.) and the beverages were placed in a thermostatically controlled 20° C. water bath and sparged with nitrogen at 100 ml / min for 1 hour with stirring.

[0537] Desorption from the adsorption trap (Turbomatrix ATD 350, Perkin Elmer) was carried out at 300°C for 15 min using a hydrogen flow of 50 ml / min into a cold trap (Perkin Elmer) packed with Tenax TA 60 / 80 (Sigma-Aldrich) and Carbopack X (Sigma Aldrich). Using a 3:1 split technique, the desorbed volatiles were focused at 4°C for 15 min and then injected through the transfer line into the gas chromatograph column by increasing the trap temperature to 300°C. The gas chromatograph (Agilent Technologies, 7890A GC-MS) was equipped with a DB-Wax column (30m x 250 μm; film thickness, 0.25 μm; Agilent technologies).

[0538] The gradient program included a 10 min isothermal step at 35 °C, a gradient at 8 °C / min to 240 °C, followed by a 5 min isothermal step. The GC was coupled to a single quadrupole mass spectrometer (5975C Agilent Technologies). The MS transfer line temperature was 250 °C and the ion source temperature was 200 °C. The mass spectrometer was scanned over the mass to charge (m / z) range of 20 to 400 and spectra were acquired using a fragmentation voltage of 70 eV.

[0539] Volatile compounds were identified using the MS database (NIST MS search version 2.0). Further confirmation of all compounds was performed by comparing mass spectral data and retention times with authentic reference compounds. The amounts of identified volatile compounds were calculated by a semi-quantitative approach using the concentration and peak area of ​​the internal standard 2-hexanone-5-methyl.

[0540] Analysis K: Sensory evaluation of UHT-treated whey protein isolates. Sensory analysis of UHT (ultra-high temperature treated) beverages was carried out at the Department of Food Science at Aarhus University.

[0541] An attribute list was created prior to the final tasting / smelling session. Attributes were rated on a 15 cm scale from 0=low intensity to 15=high intensity.

[0542] Odor evaluation Due to the volatility of the odorous compounds of the products, the samples were provided in the original bottles. The panelists had to open the bottles themselves to evaluate the odor. New bottles were used for every panelist and for every different repetition.

[0543] Flavor and mouthfeel evaluation The flavor of the beverages was evaluated by eliminating the nasal aroma effect. In this test, the samples were left open for one hour to ensure that only slight volatile substances were present during the evaluation. Furthermore, the samples were served in small plastic cups with straws. In this way, the panellists did not directly smell the samples when tasting. Furthermore, in this flavor evaluation of the samples, the panellists used a spittoon / spit cup.

[0544] Statistical analysis was performed using three-way analysis of variance (ANOVA) in the "Panelcheck" software on 30 replicates, with samples fixed but panels randomized.

[0545] Significant differences between samples were assessed using Duncan's test (software used: XLSTAT), which shows the least significant difference values ​​(pairwise comparisons between groups associated with a letter).

[0546] Analysis L: Quantification of natural BLG / ALA / CMP by RP-HPLC analysis Protein samples / powders were prepared by diluting to 2% protein with MQ water. The solution was filtered through a 0.22 μm filter to remove protein aggregates. For each sample, the same volume was loaded onto a UPLC system (ACQUITY UPLC H-Class, WATERS) with a UPLC column (Protein BEH C4; 300 Å; 1.7 μm; 150 x 2.1 mm) and detection was performed at 214 nm.

[0547] The samples were analyzed using the following conditions: Buffer A: Milli-Q water, 0.1% w / w TFA Buffer B: HPLC grade acetonitrile, 0.1% w / w TFA Flow rate: 0.4ml / min Gradient: 0–6.00 min, 24–45% B; 6.00–6.50 min, 45–90% B; 6.50–7.00 min, 90% B; 7.00–7.50 min, 90–24% B; and 7.50–10.00 min, 24% B.

[0548] The area of ​​the BLG / ALA / CMP peak was used to quantitate the amount of BLG / ALA / CMP protein using a standard curve generated using pure BLG / ALA / CMP protein standards (BLG Sigma L0130).

[0549] If outside the linear range, the sample was further diluted and re-injected.

[0550] Analysis M: Total Solids Determination The total solids of the solution may be determined according to NMKL [110, 2nd edition, 2005 (Total Solids (Water) - Gravimetric Determination of Milk and Dairy Products)]. NMKL is the abbreviation for "Nordisk Metodikkomite for Naeringsmidler".

[0551] The water content of a solution can be calculated as 100% minus the relative amount of total solids (% w / w).

[0552] Analysis N: Determination of fat content The amount of lipids was determined according to ISO 1211:2010 (Determination of fat content - Rose-Gottlieb gravimetric method).

[0553] Analysis O: Quantitative determination of lactose content Total lactose was determined according to ISO 5765-2:2002 (IDF 79-2:2002) "Dried milk, dried ice-mixes and processed cheese-Determination of lactose content-Part 2: Enzymatic method utilizing the galactose moiety of the lactose".

[0554] Analysis P: Characterization of mineral composition The total amounts of calcium, magnesium, sodium, potassium, and phosphorus are determined using a method that first uses microwave digestion to digest the sample and then uses an ICP instrument to measure the total mineral amounts.

[0555] Device The microwave instrument is from Anton Paar and the ICP is a PerkinElmer Optima 2000DV. material 1M HNO3 Yttrium (2% in HNO3) Suitable standards for calcium, magnesium, sodium, potassium, and phosphorus (in 5% HNO3)

[0556] Pretreatment Weigh out 0.2 grams of powdered sample or 1 g of liquid sample and transfer the powder to a microwave digestion tube. Add 5 mL of 1 M HNO3. Digest the sample in a microwave according to the microwave instructions. Place the digestion tube in a fume hood and remove the lid to allow volatile odors to evaporate.

[0557] Measurement method The pretreated sample is transferred to the DigiTUBE using a known amount of Milli-Q water. A solution of yttrium in 2% HNO3 is added to the digestion tube (approximately 0.25 mL / 50 mL of diluted sample) and diluted with a known volume of Milli-Q water. The sample is analyzed by ICP using the method described by the manufacturer.

[0558] Preparation of the blind samples is performed by diluting a mixture of 10 mL of 1 M HNO3 and 0.5 mL of yttrium solution (in 2% HNO3) with Milli-Q water to a final volume of 100 mL.

[0559] Prepare at least three standards with concentrations surrounding the expected sample concentrations.

[0560] The detection limits for liquid samples are 0.005g / 100g for Ca, Na, K and Phosphorus, and 0.0005g / 100g for Mg. The detection limits for powder samples are 0.025g / 100g for Ca, Na, K and Phosphorus, and 0.0005g / 100g for Mg.

[0561] Analysis Q: Determination of turbidity Turbidity is the cloudiness or cloudiness of a liquid caused by numerous particles that are generally not visible to the naked eye (similar to smoke in air).

[0562] Turbidity is measured in Nephelometric Turbidity Units (NTU).

[0563] 20 mL of beverage / sample was added to an NTU glass and placed in a Turbiquant® 3000IR turbidity meter. After stabilization, the NTU value was measured and repeated twice.

[0564] Example 1: Mild thiol oxidation at pH 8.0 and low temperature In this experiment, the inventors discovered and demonstrated for the first time that it is feasible to reduce or eliminate the unpleasant odor similar to that of rotten eggs in UHT (ultra-high temperature treated) whey protein beverages at neutral pH by mild low-temperature oxidation of whey protein free thiols at pH 8.0.

[0565] In this and subsequent examples, the expression "unpleasant odor" means an unpleasant odor similar to the odor of rotten eggs.

[0566] Materials and Methods Solutions containing 10% w / w or 6% w / w protein were prepared from powders WPI-A (99.6% native BLG) and WPI-B (50% BLG), respectively; the powders were mixed with ultrapure water (18.2 milliohms) and the mixture was then allowed to hydrate for 1 hour at approximately 20°C with gentle stirring, resulting in a clear solution with no remaining powder particles. The properties of the powders used in this study are listed in Table 1.

[0567] [Table 1]

[0568] The pH of the whey protein solutions was measured and adjusted to pH 8.0 at 20°C with 3M NaOH. A 15 mL sample in a 20 mL Duran GL 18 glass vial (with screw cap) containing the aliquot was kept for reference purposes. The WPI samples in the vials were thermally equilibrated to 10, 25, 40, 50 or 60°C in a water bath. Hydrogen peroxide (H2O2) was added to achieve a H2O2:BLG molar ratio of 5:1 or 8:1 as described in Table 2, based on the molar concentration of a 30% w / w H2O2 solution, with a density of BLG of 1.11 g / mL, molar weight of 34.01 g / mol, and molar concentration of 9.79 M, and a molecular weight of BLG of 18.4 kDa obtainable in analytical L. A similar set of 6% WPI-B samples was prepared that was adjusted to pH 6.5 and incubated at 10° C. and 25° C. in the presence of 8:1 H2O2:BLG.

[0569] BLG typically comprises about 50% or more of whey protein, and is also the primary source of free thiols in whey proteins (BLG contains one free thiol group per molecule). The molar concentration of native BLG in a whey protein composition is therefore a very close approximation of the molar free thiol group content of the whey protein composition. It is therefore meaningful to select the amount of oxidizing agent to be used based on the native BLG content of the whey protein composition.

[0570] Table 2 shows a summary of the reaction conditions at the start of the 18-hour incubation, after which a sample was set aside for analysis of residual H2O2 (according to assay H) and catalase (3.65 mL of Catazyme 25L per 150 L of liquid product) was added to stop further H2O2 oxidation of the WPI samples by H2O2 disproportionation.

[0571] The residual free thiol groups in the proteins and potential aggregates of the oxidized whey protein composition remaining as a result of treatment were analyzed by GPC-MALS according to analyses E and G, respectively.

[0572] UHT Simulation To assess the effect of the oxidative treatment on the development of unpleasant odors, samples were subjected to a UHT-like treatment as described below.

[0573] The pH of the samples was adjusted to 7.0 and diluted to 6% protein. 1.0 mL of the oxidized whey protein solution was transferred to 2 mL GC vials (Mikrolab no ML 33003VU) and crimped sealed using aluminum caps (Mikrolab ML 33032) and an electronic crimping tool (Thermo Scientific CRMA60180-ECRH11KI). Samples were visually inspected for signs of cloudiness and monitored while inverting the vials as a first indication of flow characteristics.

[0574] The above (room temperature) sealed vials were transferred to an aluminium heating block of a Mikrolab supertherm system (control unit ML306228 and heating unit ML3062409, Mikrolab A / S, Denmark) with holes drilled and prepared by the manufacturer with dimensions to fit 2 ml GC vials. The block was preheated to 160°C and the samples were kept in the block for 160 seconds. After about 40 seconds the temperature reached 100°C, in 65 seconds it reached about 120°C, after 100 seconds incubation it reached 140°C and after 160 seconds it reached 150°C. After incubation in the heating block the samples were transferred to an ice / water bath to quickly stop the reaction which leads to the development of an unpleasant odour. According to analysis D, H2S was measured directly in the sealed vials.

[0575] The inventors have shown that a simulated UHT process in which samples are incubated in an aluminum block at 160°C for 160 seconds closely mimics a conventional UHT process using indirect heating (143°C) for 4 seconds with a plate heat exchanger. The inventors further discovered that the aluminum block at 160°C produces the same amount of unpleasant odors in 160 seconds, as judged by the H2S content of the indirect UHT process at 143°C for 4 seconds.

[0576] We sensorily evaluated the samples 24 hours after simulated UHT treatment and ranked them for perceived unpleasant sulfur / spoiled odor. Just before evaluation, the vials were uncapped and the "unpleasant sulfur odor" was rated on a scale of 0 to 15, with water being a low intensity and 10 μM H2S standard prepared according to Analysis D being a high intensity of 15.

[0577] [Table 2]

[0578] result The present inventors have investigated the development of unpleasant odors in whey protein isolates (WPIs) subjected to harsh heat treatments at neutral pH (such as at 143°C for 2-16 seconds) and, by using an H2S-selective electrode, have unexpectedly discovered that the strong sulfur-like off-flavors developed in such whey protein isolate beverage compositions consist primarily of hydrogen sulfide, which is likely to result from β-elimination of cysteine ​​to hydrogen sulfide and dehydroalanine. Indeed, by utilizing detection by gas chromatography / mass spectrometry and gas chromatography / flame photometry, the present inventors have confirmed that the unpleasant odors consist primarily of H2S.

[0579] As shown in Table 3, the inventors have unexpectedly discovered specific conditions that allow for the oxidation of whey protein isolate and have demonstrated a direct relationship between the consumption of hydrogen peroxide in the process and the reduction in residual thiols, and the resulting reduction in the development of an unpleasant odor similar to that of rotten eggs in UHT treated samples.

[0580] It was particularly surprising to the inventors that exemplary WPI samples (WPI-A and WPI-B in Table 2) needed to be heated above ambient temperature, such as 40° C., such that the reaction between free thiols and hydrogen peroxide could proceed even when incubated at a higher pH of 8.0 for at least up to 18 hours. Indeed, no reduction in free thiol content was observed in the WPI-B sample of 6% WPI incubated with 8:1 H2O2:BLG at 10° C. or 25° C., pH 6.5, and thus thiol oxidation would not be expected to occur efficiently under typical industrial processing conditions where microbial growth is expected to cease at low temperatures.

[0581] A strong H2S odor was detected in the UHT-treated (ultra-high temperature treated) non-oxidized sample WPI-A1, and the inventors found that the strongly perceived rotten egg-like odor (sensory score of 10) was further associated with a high measured electrode potential of 92 mV.

[0582] In contrast, WPI-A4 sample subjected to treatment at pH 8.0 and 40°C with 5:1 H2O2:BLG resulted in 93% consumption of added H2O2 and 81% reduction in free thiols. Oxidation was found to significantly reduce unpleasant odor after UHT simulation down to a score of 4, which is similar to the level of the unheated 6% WPI-A sample. After UHT simulation, WPI-A4 sample further demonstrated a H2S electrode potential of only 9mV, confirming a significant reduction in H2S generation and a significant reduction in unpleasant odor. Samples treated at 10-25°C (samples WPI-A2 and WPI-A3, respectively) did not show any measurable unpleasant odor and were not evaluated. However, based on the consumption of H2O2 and the associated reduction in remaining free thiols, the inventors discovered that the use of higher temperatures is preferred to more efficiently remove thiols and thereby reduce H2S after nUHT treatment (ultra-high temperature treatment).

[0583] The same pattern was observed for WPI-B samples exposed to oxidizing agents at 10°C to 60°C with a molar ratio of 8:1 H2O2:BLG (samples WPI-B2 to WPI-B6, respectively). The non-oxidized samples produced a strong and unpleasant odor (sensory score of 9) similar to that of rotten eggs as indicated by the high electrode potential of 214 mV (known to correspond to a concentration of 10.4 μM). When the incubation temperature was gradually increased (10°C to 60°C; WPI-B2 to WPI-B6, see Table 3), the perceived unpleasant odor decreased to a score of 4, which was found to be similar to the unheated 6% WPI-B in samples WPI-B4 to WPI-B5. Similarly, these samples also had low levels of H2S measured. Similar to the WPI-A based samples, a relationship between consumed H2O2, residual thiols, and unpleasant odor upon subsequent UHT treatment was also observed for the WPI-B based samples.

[0584] In addition to the requirement to use higher temperatures, we unexpectedly discovered that efficient oxidation as observed in samples WPI-B4 to WPI-B6 also leads to protein aggregation, as indicated by an increase in weight average molecular weight (Mw) from 75 to 5590 kDa (corresponding to a molecular weight (Mw) of BLG molecules of about 4 to about 300) with increasing temperature from 40 to 60° C. (see Table 3). The high molecular weight of the protein in sample WPI-B6 is visually detectable by the slight cloudiness and viscous behavior when the sample is inverted.

[0585] We further observed that little or no aggregation was observed in samples treated at lower temperatures, WPI-B2 (29.3 kDa) and WPI-B3 (44.1 kDa), clearly indicating that some degree of protein denaturation is required for the oxidation process to proceed. If sufficient denaturation is reached (e.g., WPI-A4 and WPI-B4), oxidation can proceed with minimal aggregation, whereas increased denaturation leads to increased or excessive aggregation (e.g., WPI-B5 and WPI-B6).

[0586] The inventors have demonstrated that oxidation of WPI preparations can reduce and eliminate unpleasant odors for a wide range of whey protein isolate compositions having BLG contents ranging from about 100% to about 50% of total protein, as exemplified by samples WPI-A4, WPI-B4 to WPI-B6 (see Table 3).

[0587] [Table 3]

[0588] conclusion The inventors have found that UHT treatment (ultra-high temperature treatment) of samples previously subjected to oxidation under conditions allowing a significant reduction of free thiols reduces the level of an unpleasant odor similar to that of rotten eggs.

[0589] A significant reduction in unpleasant odor levels was detected in samples characterized by a free thiol content of 10 micromoles SH per gram of protein in a 6% whey protein beverage composition; unpleasant odor levels at or below 5.0 micromoles H2S were detected as significantly reduced in the sensory analysis compared to the non-oxidized reference; and unpleasant odor levels below 2 micromoles H2S were barely or not detected in the sensory analysis.

[0590] The inventors have demonstrated that the oxidation of free thiols in whey proteins and in particular BLG (the major source of free thiol groups in whey proteins) can be reduced under controlled conditions.

[0591] The inventors have further discovered that a combination of specific pH and temperature ranges is beneficial for efficient oxidation of free thiols of whey proteins.

[0592] Example 2a: Testing the effect of the level of oxidizing agent used In the experiments described in these Examples, the inventors investigated the effect of the amount of oxidizing agent used over the course of a 20 hour incubation at an incubation temperature of 40°C.

[0593] method An 8.6% WPI solution (20°C, pH 8.0) containing 43.2 g / L BLG (approximately 2.35 mM) was prepared from WPI-B by a method identical to that outlined in Example 1, except that 30% HO2 was added and mixed with varying molar ratios of HO2:BLG ranging from 0:1 to 178:1 (HO2:BLG). All solutions were incubated at 40°C for 20 hours.

[0594] After incubation, the residual H2O2 was measured according to the assay.

[0595] For further analysis and to avoid excessive oxidation in subsequent processing steps, catalase (3.65 mL Catazyme 25L per 150 L liquid whey protein product) was added to the samples for removal of residual H2O2. Residual free thiols were measured according to analysis E.

[0596] The loss of individual amino acids upon oxidation was measured and the abundance of amino acids in the oxidized whey protein samples was assessed according to assays F1 and F2.

[0597] H2S-related odor generation was evaluated after heat treatment (160 seconds using an aluminum block at 160°C) as described in Example 1. All samples were stored at room temperature for 24 hours prior to H2S analysis.

[0598] The level of non-native crosslinks resulting from conversion of cysteine ​​to dehydroalanine by β-elimination and further reaction with lysine or cysteine ​​residues was assessed on oxidized samples after UHT treatment by decapping the vials using an electronics crimper with decapper (Thermo Scientific CRMA60180-ECRH11KI) and performing Analysis I.

[0599] The perception of unpleasant odors was evaluated as described in Example 1.

[0600] result As can be seen from Table 4, the amount of residual H2O2 increases with increasing usage amount, and the inventors discovered that the ratio of residual peroxide to the amount initially added rapidly increases beyond the stoichiometric ratio of 10:1 (sample WPI-B16) to as much as 29% to 49% of the initially added H2O2 remains even after 20 hours of incubation at a constant temperature of 40°C at molar ratios of 17:1 to 178:1 (samples WPI-B18 to WPI-B21).

[0601] It was further demonstrated that the oxidation step essentially depleted free thiols, as evidenced by the fact that the amount of SH was approximately 2.2 μmol / g protein or less at a H2O2:BLG molar ratio of 8:1 (sample WPI-B15) or higher (samples WPI-B16 to WPI-B21), suggesting that residues responsible for the development of an unpleasant odor similar to that of rotten eggs were efficiently removed.

[0602] However, the inventors found that even when the amount of SH was reduced to 7.5 micromoles per gram of protein (which was found to result in 1.35 micromoles of H2S after simulated UHT treatment in sample WPI-B12), it was still perceived as being comparable to the unheated, unoxidized 6% WPI-B reference, which received a score of 4 on a scale of 0 to 15. The unoxidized 6% WPI-B9 sample, which produced high levels of H2S, was rated a score of 9.

[0603] In particular, samples WPI-B12 to WPI-B21 showed a maximum content of 10 micromoles of free thiol groups per gram of protein, resulting in a maximum of approximately 5 micromoles of H2S after simulated UHT, indicating significantly reduced unpleasant odor levels compared to the heat-treated reference WPI-B9 and similar levels to the unheated, unoxidized 6% WPI-B reference.

[0604] [Table 4]

[0605] conclusion The inventors have discovered that a certain level of oxidation is required for sufficient free thiol removal to significantly reduce the development and perception of an unpleasant odor similar to rotten egg odor during and after UHT processing of whey protein beverages. The inventors have discovered that the reduction in the level of unpleasant odor, as assessed analytically and by sensory, is consistently associated with a residual free thiol content of about 10 micromoles SH or less, and therefore about 5 micromoles H2S or less, per gram of protein.

[0606] Example 2b: Testing for Oxidative Damage The inventors have observed that prior art whey protein oxidation processes for producing beverages (see US2016 / 0235082A1) result in, inter alia, the development of turbidity and / or yellowing, resulting in an unattractive looking beverage.

[0607] The inventors speculate that these undesirable characteristics may be the result of harsh heat treatment (such as UHT) in the presence of high concentrations of oxidizing agents.

[0608] method A 13.5% w / w WPI solution was prepared by mixing WPI-B powder with Milli-Q water, adjusting the pH to 6.5 with 5% HCl, and then diluting with Milli-Q water to a final protein concentration of 13% w / w. The BLG content was 65 g / L (approximately 3.54 mM) as determined by Assay L. An aliquot of the 13% WPI-B (pH 6.5) sample was kept for reference purposes.

[0609] 30% hydrogen peroxide (H2O2) was mixed into the WPI solution in various amounts corresponding to molar ratios of H2O2:BLG ranging from 0:1 to 174:1 (see Table 5).

[0610] A 1.0 mL aliquot of the 13% WPI sample was subjected to simulated UHT treatment (160 seconds with an aluminum block at 160° C.) as described in Example 1. After cooling, the vials were visually inspected, the caps removed and the remaining unreacted H2O2 was assessed using Analysis H. Analysis E was used to measure the remaining thiols. The loss of individual amino acids in the process was determined and the abundance of amino acid oxides was assessed according to Analysis F1 and F2, respectively. The level of unnatural lanthionine crosslinks resulting from the conversion of cysteine ​​to dehydroalanine by β-elimination and further reaction with cysteine ​​residues was assessed in Analysis I for the oxidized samples after UHT treatment.

[0611] result Table 5 shows an overview of the experimental results, and Fig. 1 shows photographs of samples WPI-B22 to WPI-B30.

[0612] Turbidity was observed in most samples, and further yellowing was observed in certain samples WPI-B26, WPI-B27, WPI-B29, and WPI-B30 that had high levels of H2O2 subjected to UHT treatment, suggesting that excessive amounts of H2O2 in combination with UHT treatment could cause excessive and undesirable amino acid oxidation, resulting in, for example, such color changes.

[0613] Furthermore, the inventors found that the presence of 85:1 H2O2:BLG during UHT treatment of 13% WPI-B (WPI-B29) caused significant and undesirable loss of tryptophan residues, as well as the formation of oxides from both tyrosine and tryptophan residues (see Table 7). The inventors found evidence suggesting that the yellowing was due to the detected tryptophan oxides, dioxyindolylalanine (DiOia) and kynurenine (kyn).

[0614] Furthermore, oxidation of tyrosine to oxotyrosine (o-Tyr) and dityrosine (Di-Tyr) is considered an indicator of overoxidation.

[0615] In contrast to sample WPI-B29, Table 7 shows that in WPI-B15 (Example 2A), after a milder oxidation step of 8:1 molar ratio (H2O2:BLG) at 40° C. and subsequent disproportionation of excess oxidant with catalase, there are no significant changes in tyrosine or tryptophan residues in WPI-B15. No oxidation products of tyrosine (e.g., di-tyr and o-tyr) or tryptophan (e.g., kynurenine and DiOia-2) were observed in samples WPI-B22 (untreated WPI-B) or WPI-B9 (no H2O2 added).

[0616] It was further shown that WPI-B15 had significantly lower levels of lanthionine after UHT treatment (ultra-high temperature treatment) compared to both WPI-B9 and WPI-B29 (UHT in the presence of H2O2) (non-oxidized forms), which was surprisingly close to the levels of unmodified, unheated WPI-B (Table 7). This clearly suggests that the oxidation process reduces the formation of proteolytic products that would otherwise lead to the formation of non-native lanthionine crosslinks.

[0617] Interestingly, sample WPI-B20 (40°C / 20h, 89:1) showed no degradation of tyrosine and tryptophan, most likely a result of the addition of catalase before UHT treatment, clearly indicating that high levels of H2O2 at high temperatures are undesirable. However, the undesirable formation of the tryptophan decomposition product kynurenine was detected, highlighting the need to adjust the amount of H2O2 used.

[0618] [Table 5]

[0619] [Table 6]

[0620] [Table 7]

[0621] conclusion The inventors have observed that processing involving direct UHT (ultra-high temperature) processing of WPI solutions in the presence of high levels of H2O2 followed by bottling causes undesirable oxidation of amino acids (such as tryptophan) leading to the formation of degradants such as kynurenine and DiOia. Furthermore, the inventors have observed the formation of turbidity or yellowing in such solutions and have found evidence suggesting that this coloration may be related to the formation of amino acid degradants.

[0622] In contrast, by careful selection of the appropriate pH and temperature ranges that allow for exposure and selective oxidation of the free thiols in BLG, as described in Example 2A, it becomes feasible to produce modified whey protein compositions and beverage products containing them that have lower free thiol group contents and significantly reduced levels of oxidative damage.

[0623] Example 3: Effect of pH on enabling thiol oxidation In this experiment, we investigated the effect of pH on enabling free thiol oxidation of whey proteins.

[0624] Materials and Methods Aqueous samples of dissolved WPI-B (containing enough WPI-B powder to give a protein content of 8.4% w / w) were prepared by mixing the powder with demineralized water as described in Example 1. The pH of the samples was adjusted to 6.5, 7.0, 7.5, 8.0, and 8.5, respectively, using 10% HCl or 3M NaOH, respectively. Unless otherwise noted, pH-adjusted WPI-B samples were incubated at 40-55°C for 20 hours after addition of H2O2 at a molar ratio of 8:1 H2O2:BLG (see Table 8). After incubation, residual H2O2 was measured using an assay H.

[0625] Catalase (3.65 mL of Catazyme 25 L per 150 L of liquid product) was added to remove residual H2O2.

[0626] To estimate the average molecular weight and intrinsic viscosity of the obtained product, the sample was analyzed by gel permeation chromatography (GPC) according to analysis G. The residual free thiol was measured according to analysis E.

[0627] A sub-sample was subjected to a UHT-like heat treatment as described in Example 1 (with an aluminium block at a temperature of 160° C. for 160 seconds) and the H2S content was assessed according to Analysis D.

[0628] The perceived unpleasant odor was evaluated as described in Example 1.

[0629] result Table 8 shows that certain temperature / pH combinations are required to allow free thiol oxidation.

[0630] Untreated WPI-B31 and WPI-B32 incubated at pH 8.0 and 40°C in the absence of added H2O2 showed high levels of free SH, 21.6 and 21.5 μmol SH / g protein, and showed high levels of unpleasant odor after UHT treatment (ultra-high temperature treatment), as shown in WPI-B31.

[0631] However, we found that gradually increasing the temperature increased H2O2 consumption, resulting in a reduction in free thiols to 2.2 micromoles SH / g protein at pH 8.0, and therefore reduced the level of H2S produced during UHT treatment.

[0632] The reaction requires a pH of about 8.0 at 40° C., but the inventors have further discovered that the reaction can proceed at a pH below 8.0 if the temperature is simultaneously increased to promote partial denaturation of the protein, meaning that certain temperatures are required for certain pH levels.

[0633] Indeed, as can be seen from sample WPI-B38, it was found that efficient removal of unpleasant odors at pH 7.0 required an incubation temperature of at least about 50°C; and at pH 6.5, a temperature of at least about 55°C was required.

[0634] As evidenced by samples WPI-B35 through WPI-B39, the inventors further noticed that as a result of efficient oxidation and removal of unpleasant odors, the weight average molecular weight of the modified WPI products increased from 51 (WPI-B35) to 1142 kDa (WPI-B39) compared to 22.4 kDa for the untreated WPI-B raw material.

[0635] The inventors further noticed that, although the measured level of unpleasant odor generated during UHT treatment of samples characterized by a content of free thiols below 7.4 micromoles SH per gram of protein was found to be higher than the measured sensory threshold of 1-2 micromoles H2S, the unpleasant odor of WPI-B35 had already decreased the next day (24 hours at ambient temperature) to a level similar to that of the unheated, unoxidized 6% WPI-B sample. No unpleasant odor was detected at all in samples WPI-B36 to WPI-B39.

[0636] [Table 8]

[0637] conclusion The inventors found that increasing pH enhances the reduction of free thiols in whey proteins. As further evident from Table 8, increasing from pH 6.5 to pH 7.0 and also from pH 7.0 to pH 7.5 dramatically enhances the reduction of "SH groups per gram of protein" per H2O2 consumption. Without being limited by theory, the inventors speculate that increasing pH loosens the molecular structure of BLG, thus allowing the oxidizing agent to more easily access the free thiols of BLG, increasing the specificity of the oxidation reaction.

[0638] The method of the invention may be carried out at pH 6.5, but will preferably require higher temperatures (e.g., 50° C.) and longer incubation times to accelerate the process by partial denaturation of the protein to facilitate access of the oxidizing agent to the free thiols.

[0639] The inventors further observe a tendency for the average molecular weight to increase as the temperature increases during heat treatment.With regard to the production of oxidized whey protein powders, the inventors have discovered that it is advantageous to keep the aggregate size as small as possible, as this allows for the processing of higher protein concentration streams without the problem of increased viscosity.

[0640] Example 4: Production of a pH neutral UHT whey protein beverage for sports nutrition In this example, the inventors have demonstrated the feasibility of scaling up the process to a pilot scale for oxidized whey protein with surprisingly low levels of off-flavors after UHT treatment at neutral pH.

[0641] Materials and Methods In pilot plants using powders of WPI-B or WPI-C type as raw materials, instant beverages were produced with neutral pH and low levels of unpleasant odors after UHT treatment. The powder composition of WPI-B is shown in Example 1 and WPI-C is shown in Table 9.

[0642] [Table 9]

[0643] In the experimental treatment, 12 kg of solution containing 6% w / w protein (WPI-B or WPI-C) was prepared, followed by 30 min of rehydration. The pH was adjusted to 8.0 at 20°C with 10% NaOH. The solution was then transferred to a Scanima mixer (SPM-100V, Scanima A / S, Denmark) and the temperature of the solution was raised to 40°C under gentle stirring. 35% H2O2 was then added to the solution to achieve a molar ratio between H2O2 and BLG of WPI-B or WPI-C of 8:1. The solution was kept at 40°C for 18 h, and catalase was added at the end of the 18 h incubation to remove excess H2O2, as described in Example 1. The solution was left at room temperature for 60 min and the pH was adjusted to 7.0 with 1 M HCl before UHT. The UHT heat treatment was carried out using a plate heat exchanger (PHE) (HT320-20, OMVE, The Netherlands) with a tap water flow of 80 L / h, a product flow of 20 L / h, preheating to 70°C, followed by heating to 143°C for 4 seconds. At the outlet, the heat-treated beverage was cooled to 10°C and poured into 100 ml sterile plastic bottles and immediately sealed for further analysis. Additionally, samples for H2S level analysis were filled at the UHT outlet. Then, 1 ml samples (three replicates for each sample) were poured into 2 ml glass vials and immediately capped and crimp-sealed as described in Example 1.

[0644] Several analyses were performed to evaluate the beverages. Residual free thiols were measured according to analysis E on samples after 18 hours of oxidation. The beverages were analyzed for H2S levels within 2 hours of production (analysis D). All samples were stored at room temperature before H2S measurement. Turbidity analysis was performed by analysis Q.

[0645] Sensory evaluation was performed on the same day as the beverage was produced, with the 100 ml plastic bottles stored at room temperature before opening. The bottles were opened and directly evaluated by 3-5 people (2 bottles per person). A scale of 0-15 was used.

[0646] result The results clearly show that the amount of free thiols was significantly reduced by oxidation of WPI-B or WPI-C at a molar ratio of 8:1 H2O2 to BLG compared to untreated samples as shown in Table 10. Furthermore, UHT treatment increased the H2S levels in the beverages in both WPI-B37 and WPI-C1 without H2O2 addition. However, when H2O2 was added (samples WPI-B38 and WPI-C2), the unpleasant odors after 24 hours of storage at room temperature were at levels below the measured sensory threshold.

[0647] The low turbidity and low levels of unpleasant odor observed in the 6% WPI-B beverage clearly demonstrate the preference for the use of pre-treated WPI products for producing clear whey protein beverages with good palatability.

[0648] [Table 10]

[0649] conclusion The inventors have demonstrated that the oxidation process can be successfully used on a pilot scale to produce a clear, neutral pH UHT whey protein beverage that is free of unpleasant odors similar to that of rotten eggs, which may be particularly attractive for sports nutrition.

[0650] Example 5: Production of neutral pH UHT whey protein powder for sports nutrition In this example, the inventors demonstrated the feasibility of using the conditions described in Example 4 in the production of a powder product process involving concentration and spray drying to produce a modified whey protein isolate that exhibits surprisingly low levels of off-flavors after rehydration and UHT treatment at neutral pH.

[0651] Removing water is particularly advantageous in the following cases: If such products are transported over long distances (avoiding water transport), To reduce the risk of microbial growth during storage.

[0652] Materials and Methods A 150 kg solution containing 10.3% or 7.9% protein WPI-C (properties as described in Example 4, Table 9) was prepared by hydrating WPI-C with water for 30 minutes. The pH of the solution was adjusted to 8 (20° C.) before heating the solution to 40° C. For the above heated solutions, the pH was adjusted to 7.7 (measured at 40° C.) before adding H2O2 using a molar H2O2:BLG stoichiometric ratio of 7.5:1 or 13:1.

[0653] After 20 h incubation at 40° C., 96 U of catalase (Sigma C9322) per g protein was added to inactivate residual H2O2. The oxidized WPI was then concentrated to 12% protein in a pilot-scale MMS NF / RO unit equipped with two Koch HFK328 (3838 / 31) membranes and operated in UF mode at an average pressure differential of 0.9 bar at 10° C. The UF retentate was then dried in an SPX Anhydro pilot-scale spray dryer (temperature: 185° C. inlet / 85° C. outlet).

[0654] The produced oxidized WPI powder was mixed with demineralized water to obtain whey protein beverages (WPI-C4 and WPI-C5) containing 5.9% protein. The pH of the solution was adjusted to 7.0 (20°C) using 3% HCl. The WPI-C4 solution was subjected to UHT at 143°C for 4 seconds using an OMVE HT320-20 equipped with a PHE as described in Example 4. In the same way, a reference beverage was prepared from WPI-C powder (without oxidation pretreatment, WPI-C3).

[0655] The WPI-C5 solution was thermally treated using a tubular heat exchanger (THE) utilizing a UHT APV / SPX 5010026 system operated at 100 L / hr and consisting of two stages of pre-heating (i.e., first at 80° C. and then at 100° C.) followed by heating at 143° C. for 10 seconds (high temperature, short time (HTST)). The beverage composition was then cooled in three stages, first to 78° C., then to 40° C. and finally to 10° C., and poured into 100 mL sterile bottles which were immediately sealed.

[0656] The UHT treated beverage was analyzed for free thiol group content in analysis E; and its H2S in analysis D; its turbidity in analysis Q; its viscosity in analysis C; and its sensory properties in analysis K.

[0657] result In the WPI-C4 and WPI-C5 beverages, the free thiol levels per gram of protein were reduced to 2.0 and 0.3 micromoles per gram of protein, respectively. As can be seen from Table 11, oxidation of thiols in WPI-C4 and WPI-C5 resulted in UHT-treated beverages with similar viscosity, slightly lower turbidity, and importantly, significantly reduced H2S levels compared to WPI-C3 (non-oxidized reference). The sensory panel observed reduced sulfur / rancid odor in the oxidized WPI-C5 beverage compared to the reference beverage (WPI-C3) shown in Table 12. The above characteristics were rated (Analysis K) with a score of 0 (low intensity) to 15 (high intensity). The sensory score of the WPI-C5 beverage approaches that of the unheated whey protein solution with a score of 1.7.

[0658] [Table 11]

[0659] [Table 12]

[0660] conclusion It was demonstrated that a powdered oxidized WPI-C4 / C5 product can be produced by specific oxidation of free thiol groups, inactivation of excess oxidizing agent, followed by concentration by ultrafiltration and spray drying. Having the oxidized WPI-C4 / C5 in powder form improves the logistics and shelf life of this product. Furthermore, the produced oxidized WPI-C4 / C5 powder was shown to be completely free of the sulfurous / rancid odors strongly perceived in UHT-processed beverages containing 6% WPI-C4 / C5 protein, approaching the sensory score of unheated whey protein solution.

[0661] The beverage has a low viscosity and low turbidity compared to a non-oxidized WPI reference beverage that has been subjected to a similar UHT treatment.

[0662] Example 6: Advantages of keeping pH constant during oxidation In previous studies, the inventors found that the oxidation process can lower the pH by as much as 0.5 pH units or more.

[0663] In this example, the inventors have demonstrated that it can be particularly advantageous to keep the pH constant using a pH stat in order to reduce the processing time required for the oxidation step.

[0664] Part 1: Possible improvement of reaction rate by readjusting pH during oxidation Materials and Methods 150 kg of WPI-C solution (9% protein; properties as described in Example 4, Table 9) was hydrated, pH adjusted and heated as described in Example 5, but oxidation was performed with a 10:1 molar ratio of H2O2 to BLG. 20 minutes after H2O2 addition, two 100 ml samples were poured into beakers, closed and placed in a 40°C water bath with stirring. One of the two samples had no pH adjustment during the oxidation course (WPI-C8), the other had the pH readjusted to 7.7 (measured at 40°C) after 3 hours (WPI-C7). The remaining 150 kg solution was kept at 40°C and the pH readjusted every 20 minutes for 5 hours to a static pH of 7.7, after which oxidation was continued but the pH was allowed to drop, for a total of 22 hours (WPI-C6). Samples were taken from each beaker at 3 hours (3h), 5 hours (5h), and 7 hours (7h) after H2O2 addition, as well as from the large volume in which static pH was maintained. Residual H2O2 in the samples was measured according to Assay H before adding 5 U catalase per ml to disproportionate the residual H2O2. All samples were then analyzed for free thiols according to Assay E.

[0665] result It was found that a static pH of 7.7 during oxidation significantly improved the reaction rate, allowing a free thiol content of 2.0 micromoles per gram of protein after only 7 hours, whereas neither WPI-C7 nor WPI-C8 reached that level at 24 hours. A single pH readjustment in WPI-C7 after 3 hours of oxidation also improved the rate. These results highlight the influence of pH in promoting thiol oxidation.

[0666] [Table 13]

[0667] Part 2: Effect of H2O2:BLG ratio during oxidation at static pH Materials and Methods A 10% protein solution of WPI-C was prepared and its pH was adjusted to pH 8.0 (20°C). 400 g of the solution was distributed to each of the four reactors of a BioXplorer 400 (HEL) instrument equipped with temperature control, mechanical stirrer, pH sensor, and liquid dosing system for base addition (7% NaOH) and controlled by the WINBIO software control system. The system was programmed to heat the solution to 40°C before pH adjustment to pH 7.7 and to keep the pH constant at 7.7 for 14 hours at 40°C by adding 7% NaOH solution. When the pH and temperature were stable, H2O2 was added manually to the reactors according to the following scheme: 6 ml samples were taken at intervals of 1-1.5 hours during the course of oxidation. Residual H2O2 in the samples was measured according to the assay H and the remaining samples were added with 10 U of catalase per ml of sample. The samples were adjusted to pH 7 (20°C) and diluted to 6% protein. All samples were analyzed for free thiols according to analysis E. 1 ml of each sample was subjected to UHT-like heat treatment as described in Example 1 (160 seconds with an aluminium block at a temperature of 160°C) and analyzed for H2S according to analysis D. Viscosity was measured according to analysis C.

[0668] result

[0669] [Table 14]

[0670] It was found that increasing the dose of added H2O2 decreased the time required for thiol oxidation, with a dose of 18:1 molar ratio being able to eliminate unpleasant odors within the first 5 hours when using a static pH, compared to approximately 8 hours required when using a 9:1 molar ratio of H2O2:BLG.

[0671] conclusion These experiments demonstrated that maintaining a favorable constant pH allowed for faster reaction rates (compared to WPI-C7 and WPI-C8), likely as a result of maintaining a partially denatured state determined by the temperature / pH combination.

[0672] Furthermore, the above experiments showed that the reaction time could be shortened by using higher dosages, and the process time could be significantly shortened by using a pH stat and higher H2O2:BLG dosages in combination. For example, the unpleasant odor generated by UHT treatment could be eliminated by performing oxidation pretreatment at pH 8.0 (20°C) with a H2O2:BLG ratio of 18:1 for 3 hours or a H2O2:BLG ratio of 9:1 for 5 hours.

[0673] Example 7: Effect of fat content of whey protein source The experiments described in this Example investigated the effect of fat content on the development of undesirable odors from volatile organic compounds (in addition to the unpleasant odors mentioned above).

[0674] Materials and Methods

[0675] [Table 15]

[0676] 8% protein solutions were prepared from WPI-B and WPC, respectively, by hydrating the powders for 1 hour at room temperature with gentle stirring. The pH was adjusted to 8.0 (20°C). 30% hydrogen peroxide was added to give a molar stoichiometry of 8:1, and both samples were incubated at 40°C for 20 hours at pH 8.0.

[0677] The above samples were subjected to UHT treatment as described in Example 1 to assess H2S content according to Analysis D. 5 mL samples were taken from the heat treatment vials and transferred to 100 mL blue cap flasks. 1.5 μL of 100 ppm 2-hexanone-5-methyl internal standard solution was added for a final concentration of 30 ppb. Samples were analyzed for volatile organic compounds according to Analysis J.

[0678] result WPC and WPI beverages treated with 8:1 H2O2 at pH 8.0 and 40°C for 20 hours were analyzed for volatile organic compound content. Dynamic headspace sampling gas chromatography with mass spectrometry for identification was used. The analysis revealed that all organic compounds detected were significantly more abundant in the headspace of the WPC beverage. Aldehydes, especially hexanal, heptanal, 2-4 nonadienal (E,E), nonanal, and benzaldehyde, were present in significantly higher amounts compared to the WPI. These aldehydes are derived from the oxidation of lipids, and since WPC contains significantly more lipids than WPI, the formation of aldehydes also occurs at a higher rate from WPC. To avoid the formation of volatile aldehyde substances, it is preferable to use protein sources with as little fat as possible. In addition, WPC also contains more of the ketone 2-butanone and organic acids (acetic acid, formic acid, and benzoic acid).

[0679] The combined effect of the increased presence of total volatile organic compounds in the headspace of the WPC beverages was an undesirable and significantly stronger odor compared to the WPI, as confirmed by a simple sensory evaluation, which revealed an even stronger and more complex odor in the WPC samples compared to the WPI, likely due to the generation of detected volatile organic compounds.

[0680] [Table 16]

[0681] conclusion The inventors have discovered that whey protein sources with as little fat as possible are preferred for the preparation of oxidized whey protein products and their palatable production.

[0682] Example 8: Use of thermal gradients The inventors have found that removal of free thiols can be particularly efficient when a different temperature profile is used to partially denature proteins, aiming at oxidizing the free thiols to sulfenic acids and then reacting the sulfenic acids with the exposed thiols in a second temperature step to form disulfide bonds between the proteins.

[0683] method Protein solutions of 1%, 2%, 3%, 4%, 5%, and 6% w / w were prepared from WPI-A (see Example 1) by hydrating the powder with 10 mM phosphate buffer (pH 7.0) at room temperature for 1 hour with gentle stirring.

[0684] 30% hydrogen peroxide was diluted to 0.3% in Milli-Q water and added to the protein solution at a molar stoichiometry of 2:1. The samples were then heat treated in a PCR machine (Esco Healthcare SwiftMax Pro) using a temperature / time step gradient (25°C to 99°C in 5°C intervals with a 10.5 min hold time for a total time of 176 min). Samples were cooled to 25°C before analysis.

[0685] All samples were subjected to free thiol analysis (analysis E) and particle size analysis by GPC-HPLC (analysis G).

[0686] result Surprisingly, it was found that it was possible to reduce the free thiol content by 95% using only a 2:1 molar stoichiometry at protein concentrations between 1% and 6%. The measured free thiols are shown in Table 15.

[0687] [Table 17]

[0688] At higher protein concentrations as shown in Table 15, aggregation increased, but surprisingly, protein aggregation at high protein concentrations may be limited.

[0689] conclusion Removal of free thiols can be achieved at very low HO:BLG ratios by careful design of a thermal profile that (1) allows exposure and oxidation of free thiols to the sulfenic acid state at a low temperature range selected by one of skill in the art to result in minimal aggregation, and (2) then allows reaction between the sulfenic acid and non-oxidized free thiol residues at higher temperatures.

[0690] In the practice of the invention in this example, the inventors have found evidence suggesting that the selectivity of cysteine ​​oxidation is enhanced, thereby reducing, for example, methionine oxidation.

[0691] Example 9: Use of low dose oxidizing agents in combination with post-oxidation heat treatment The inventors have demonstrated that the use of low dose oxidizing agents in combination with heat treatment can reduce free thiol levels to a desired range such that H2S concentrations are below the sensory threshold.

[0692] Mild oxidation using low levels of oxidizing agent and short incubation times (e.g., 1 hour) can oxidize partially denatured protein molecules to form sulfenic acids. Sulfenic acids are transient intermediates generated during the reaction of cysteine ​​residues with peroxide, which can be further oxidized to form sulfinic or sulfonic acids in the presence of desired levels of peroxide and / or long reaction times (e.g., 8:1 for 18 hours in Examples 1 and 2). On the other hand, in the presence of free thiols, sulfenic acids can be consumed by disulfide bond formation. In this example, we used low levels of oxidizing agent (e.g., 2:1 for short reaction times, e.g., 1 hour). The oxidizing agent oxidizes some free thiols to form sulfenic acids, which then promote disulfide bond formation with the remaining free thiols in the second heating or UHT treatment.

[0693] Materials and Methods The pH of a 6% (w / w; with respect to protein) WPI-C solution (details on WPI-C powder are given in Example 4) was adjusted to 8.0 at 20°C (analysis B) and placed in a water bath at 40°C. After the temperature of the protein solution reached 40°C, 30% H2O2 was slowly added at 2:1 (molar ratio between H2O2 and BLG) while stirring. An incubation at 40°C for 1 hour was then performed. The oxidized protein solution was then removed from the wa...

Claims

1. A method for producing an oxidized whey protein composition, comprising: (a) A step of processing a whey protein source to provide a whey protein solution to be oxidized, Here, the whey protein solution to be oxidized is • Contains an oxidizing agent capable of oxidizing the thiol group of cysteine, and pH in the range of 6.5 to 9.5 - A total protein content of at least 1% w / w relative to the weight of the whey protein solution to be oxidized. • A β-lactoglobulin (BLG) content of at least 10% w / w relative to total protein. Preferably, the protein content is at least 30% w / w relative to the total solids. Preferably, a total fat content of up to 3% w / w relative to total solids. Having; And the whey protein solution to be oxidized here is further: (i) Having a temperature in the range of 0 to 160°C, and / or (ii) Pressurized to a pressure in the range of 20 to 4000 bar, Process for processing whey protein sources; (b) Preferably, for the purpose of reducing the amount of free thiol groups in the whey protein solution to a maximum of 15 micromoles per gram of protein, the step of incubating the whey protein solution to be oxidized under one or more conditions that allow for the oxidation of at least a portion of the free thiols of the BLG molecules in the whey protein solution to be oxidized, Here, one or more of the above conditions (I) The whey protein solution to be oxidized has a temperature in the range of 0 to 160°C. and / or (II) Pressurize the whey protein solution to be oxidized to a pressure in the range of 20 to 4000 bar. A step of incubating the whey protein solution to be oxidized, including the following: (c) Optionally, and more preferably, subjecting the oxidized whey protein solution or protein concentrate obtained in step (b) to a heat treatment step, which includes heating to a temperature of at least 60°C; (d) Optionally, more preferably, a step of drying a liquid material containing protein derived from the oxidized whey protein solution obtained in step (b), A method comprising steps (a) to (d).

2. A method according to claim 1, wherein the oxidizing agent capable of oxidizing the thiol group of cysteine ​​comprises or consists of a peroxide, ozone, dioxygen, or a combination thereof.

3. The method according to Claim 1, wherein the oxidizing agent capable of oxidizing the thiol group of cysteine ​​is a peroxide selected from the group consisting of hydrogen peroxide, benzoyl peroxide, and mixtures thereof.

4. The method according to Claim 1, Here, the whey protein solution to be oxidized in step (a) - An oxidizing agent capable of oxidizing the thiol group of cysteine; and • Total amount of free thiol groups, A method in which the molar ratio between them is at least 1:2, more preferably at least 1:1, even more preferably at least 2:1, and most preferably at least 3:

1.

5. The method according to Claim 1, Here, the whey protein solution to be oxidized in step (a) - An oxidizing agent capable of oxidizing the thiol group of cysteine; and • Total amount of free thiol groups, A method wherein the molar ratio between them is 1:2 to 15:1, more preferably 1:1.5 to 10:1, even more preferably 1:1 to 8:1, and most preferably 1:1 to 3:

1.

6. The method according to claim 1, wherein the pH of the whey protein solution to be oxidized in step (a) is in the range of 7.0 to 9.5, more preferably 7.1 to 8.5, even more preferably 7.2 to 8.5, and most preferably 7.4 to 8.

2.

7. The method according to claim 1, wherein the total fat content of the whey protein solution to be oxidized in step (a) is at most 1% w / w, more preferably at most 0.5% w / w, more preferably at most 0.2% w / w, and most preferably at most 0.1% w / w, relative to the total solids.

8. A method according to Claim 1, wherein condition (i) comprises the oxidizing whey protein solution of step (a) having a temperature in the range of 5 to 65°C, more preferably 10 to 65°C, even more preferably 30 to 60°C, and most preferably 40 to 55°C.

9. A method according to Claim 1, wherein condition (i) comprises the oxidizing whey protein solution of step (a) having a temperature in the range of 66 to 160°C, more preferably 70 to 145°C, even more preferably 75 to 120°C, and most preferably 80 to 100°C.

10. A method according to claim 1, wherein condition (ii) is to pressurize the whey protein solution to be oxidized in step (a) with a pressure in the range of 20 to 4000 bar, more preferably 200 to 3500 bar, even more preferably 300 to 3000 bar, and most preferably 500 to 2500 bar.

11. A method according to claim 1, wherein condition (ii) is to pressurize the whey protein solution to be oxidized in step (a) with a pressure in the range of 25 to 1000 bar, more preferably 30 to 500 bar, even more preferably 35 to 300 bar, and most preferably 40 to 200 bar.

12. The method according to claim 1, wherein step (b) reduces or is carried out to reduce the initial amount of free thiol groups in the whey protein solution to be oxidized in step (a) to 20-80%, more preferably 30-80%, even more preferably 50-75%, and most preferably 60-75% of the initial amount.

13. A method according to Claim 1, wherein step (b) reduces or is carried out to reduce the amount of free thiols in the whey protein solution to be oxidized to a maximum of 10 micromoles per gram of protein, more preferably a maximum of 8 micromoles per gram of protein, more preferably a maximum of 5 micromoles per gram of protein, even more preferably a maximum of 3 micromoles per gram of protein, and most preferably a maximum of 2 micromoles per gram of protein.

14. The method according to Claim 1, wherein - The amount of oxidizing agent consumed in process (b), excluding the amount of excess oxidizing agent removed at the end of process (b), and - Initial amount of free thiol groups in process (a), A method in which the molar ratio between is 1:2 to 30:1, more preferably 1:2 to 25:1, even more preferably 1:1 to 20:1, and most preferably 1:1 to 15:

1.

15. The method according to Claim 1, wherein - The amount of oxidizing agent capable of oxidizing the thiol groups of cysteine ​​consumed in step (b), excluding the amount of excess oxidizing agent removed at the end of step (b), and - Initial amount of free thiol groups in process (a), A method in which the molar ratio between is 1:4 to 15:1, more preferably 1:3 to 10:1, even more preferably 1:2 to 5:1, and most preferably 1:2 to 2:

1.

16. A method according to Claim 1, wherein the time required for step (b) is a maximum of 12 hours, more preferably a maximum of 6 hours, even more preferably a maximum of 3 hours, and most preferably a maximum of 1 hour.

17. A method according to Claim 1, wherein step (b) is to stop the oxidation by contacting a component, preferably catalase, that removes a residual oxidizing agent capable of oxidizing the thiol group of cysteine ​​with the whey protein solution to be oxidized.

18. A method according to claim 1, further comprising step (c), which includes subjecting the oxidized whey protein solution obtained in step (b) to a heat treatment step.

19. A composition of oxidized whey protein; • Protein content of at least 30% w / w relative to total solids, - Up to 15 micromoles of free thiol groups per gram of protein. - Tryptophan content of at least 0.7% w / w relative to total protein, • Methionine content of at least 0.3% w / w relative to total protein, • Maximum kynurenine content of 0.2 micrograms per mg of protein. Preferably, the fat content is up to 3% w / w relative to the total solids. Preferably, the content of protein-bound sulfur is in the range of 100 to 600 micromoles per gram of protein. Preferably, the content of protein-bound cysteine ​​residues that form disulfide bonds is in the range of 150 to 400 micromoles per gram of protein. A whey protein composition having the following properties.

20. An oxidized whey protein composition according to claim 19, wherein the weight-average molecular weight of the protein is in the range of 18 kDa to 10,000 kDa, more preferably 50 to 8,000 kDa, and most preferably 80 to 5,000 kDa.

21. An oxidized whey protein composition according to claim 19, wherein at least 60% w / w, more preferably at least 80% w / w, even more preferably at least 90% w / w, and most preferably at least 99% w / w of the protein has a molecular weight of 18 kDa to 10,000 kDa.

22. An oxidized whey protein composition according to claim 19, wherein the protein content is at least 86% w / w of the total solids, and most preferably at least 90% of the total solids.

23. An oxidized whey protein composition according to claim 19, wherein the fat content is up to 1% w / w and most preferably up to 0.2% relative to the total solids.

24. An oxidized whey protein composition according to claim 19, comprising a maximum of 10 micromoles of free thiol groups per gram of protein, and most preferably a maximum of 5 micromoles of free thiol groups per gram of protein.

25. An oxidized whey protein composition according to claim 19, wherein the tryptophan content is 0.7 to 3% w / w of total protein, and most preferably 1.0 to 3% w / w of total protein.

26. An oxidized whey protein composition according to claim 19, wherein the methionine content is 0.3 to 3.3% w / w, and most preferably 1.3 to 3.2% w / w, relative to the total protein.

27. An oxidized whey protein composition according to claim 19, having a kynurenine content of up to 0.2 micrograms per mg of protein, and most preferably up to 0.01 micrograms per mg of protein.

28. An oxidized whey protein composition according to claim 19, wherein the oxidized whey protein composition is in powder form.

29. An oxidized whey protein composition according to claim 19, wherein the oxidized whey protein composition is in liquid form.

30. An oxidized whey protein composition according to claim 19, which can be obtained by the method described in claim 1.

31. A heat-treated, preferably heat-sterilized, beverage having a pH of 5.5 to 8.5, more preferably 6.5 to 7.5, and containing in an amount sufficient to contribute at least 0.5% w / w of the oxidized whey protein composition described in one or more of claims 19 to 30 to the protein, and preferably the H of the beverage 7 days after production. ２ A heat-treated beverage having a sulfur content of up to 5 micromoles / L, more preferably 3 micromoles / L, even more preferably 1.0 micromoles / L, and most preferably up to 0.7 micromoles / L.

32. Food ingredients, The food ingredient in question is: - Solid matter of the oxidized whey protein composition according to one or more of claims 19 to 30, and • One or more additional components, preferably: • Milk components, preferably non-oxidized milk components, • Plant-derived ingredients, • Non-dairy carbohydrate sources, Flavoring and odor-correcting agents, and / or • Sweeteners (sweetened carbohydrates / polyols / HIS), Ingredients selected from, Food ingredients that include this.

33. A food component according to claim 32, wherein the solids of the oxidized whey protein composition according to one or more of claims 19 to 30 contribute 0.5 to 95% w / w of the weight of the food component, more preferably 1 to 90% w / w, even more preferably 5 to 85% w / w, and most preferably 10 to 80% w / w of the weight of the food component.

34. A food component according to claim 32, wherein the solids of the oxidized whey protein composition according to one or more of claims 19 to 30 contribute 0.5 to 95% w / w of the protein of the food component, more preferably 1 to 90% w / w, even more preferably 5 to 85% w / w, and most preferably 10 to 80% w / w of the protein of the food component.

35. A food component according to claim 32, comprising a maximum of 15 micromoles per gram of protein, more preferably a maximum of 14 micromoles per gram of protein, even more preferably a maximum of 13 micromoles per gram of protein, and most preferably a maximum of 12 micromoles per gram of protein, of free thiol groups.

36. A food component according to claim 32, comprising a maximum of 10 micromoles per gram of protein, more preferably a maximum of 8 micromoles per gram of protein, more preferably a maximum of 5 micromoles per gram of protein, even more preferably a maximum of 3 micromoles per gram of protein, and most preferably a maximum of 2 micromoles per gram of protein, of free thiol groups.

37. A food component according to claim 32, wherein the food component is in powder form and preferably contains up to 6% w / w of water.

Images