Low-lipid oat protein composition without trace amounts of organic solvents

Abstract

The present invention relates to the field of oat protein compositions and methods for their production. Specifically, the present invention relates to oat protein compositions having a low lipid content and free of trace amounts of organic solvents and methods for their production.

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of oat protein compositions and methods for their production. Specifically, the present invention relates to oat protein compositions having a low lipid content and free of trace amounts of organic solvents and methods for their production. BACKGROUND OF THE INVENTION

[0002] Oats are a well-known source of various useful products. Examples of such products are flour, starch, protein isolates and concentrates, protein-rich flour, bran, chewing gum base, and oil. Due to processing problems associated with the presence of lipids in oats, traditional techniques used in the cereal processing industry are generally difficult to use with oats. In addition, unless the oats are defatted before milling, the milling process will result in the formation of lipid-containing flour and protein fractions, which can lead to rancidity during storage of the flour and protein.

[0003] The most widely used techniques include a first defatting step by means of an organic solvent such as hexane or ethanol. Those skilled in the art are aware of, for example, EP0051943 from DUPONT, which teaches the use of aliphatic hydrocarbon solvents to remove lipids from oat flour. The main drawbacks of such techniques are the industrial use of organic solvents, the associated explosion risks and spoilage, and the residual amounts of lipids in the final product.

[0004] Such risks seem so important that the main commercial products currently known as are currently produced without defatting. EP1706001 is based solely on the use of amylase and centrifugation. As disclosed in the Examples section, such a method produces a composition having a lipid content higher than 10% by weight based on the total weight.

[0005] To address these drawbacks, several alternative methods have recently been proposed. Such methods are based on the use of supercritical CO 2 . Those skilled in the art are aware of EP2120604 from VALTION TEKNILLINEN. However, in order to achieve a high level of defatting, the flour needs to be processed and milled, resulting in an average particle size of the protein below 10 microns (see paragraph 0047 of EP2120604). This method produces an ultra-fine sized protein powder, which is undesirable in some applications and difficult to handle in industrial plants, mainly due to dust formation and explosion hazards. Another major industrial problem associated with particles smaller than 10 microns is that the cyclone separators and filtration systems required to recover such small particles are expensive and difficult to operate efficiently and / or effectively.

[0006] US 2009 / 0155444 A1 discloses an extrudate made from soy protein and oat flour. It does not describe an oat protein composition.

[0007] The document by Brückner - Gühmann et al., (Foaming characteristics of oat protein and modification by partial hydrolysis, European Food Research and Technology, Vol. 244, n°12, 28 August 2018, pages 2095 - 2106) describes the production of oat protein isolate using oat protein concentrate as the starting material, the steps of extracting the concentrate with alkali, separating the protein into the supernatant, and freeze - drying the supernatant to produce oat protein isolate powder. The foaming functionality of the obtained protein isolate was explored. This document does not disclose the average particle size of the obtained oat protein composition.

[0008] The object of this patent application is to overcome these problems and thus proposes a new method to improve the prior art, thereby providing a unique oat protein powder. Detailed Description

[0009] The first embodiment of the present invention is an oat protein composition, characterized in that the composition does not contain trace organic solvents, has a residual lipid content of less than 10% by weight based on the total dry weight of the oat protein composition in dry matter, and has an average particle size greater than 10 microns.

[0010] The second embodiment is a method for producing an oat protein composition, which, based on the total dry weight of the oat protein composition in dry matter, has a residual lipid content of less than 10% by weight. The oat protein composition can be the oat protein composition of the present invention as defined above, and is characterized in that the method comprises the following steps:

[0011] 1) Prepare oat seeds or provide protein - rich flour;

[0012] 2) In the case of using oat seeds in step 1, grind the oat seeds of step 1 until protein - rich flour is obtained;

[0013] 3) Mix the protein - rich flour of step 1 or 2 with water until a protein - rich suspension is obtained;

[0014] 4) Add amylase to the protein - rich suspension of step 3 to hydrolyze the protein - rich suspension;

[0015] 5) Optionally, separate the hydrolyzed protein-rich suspension of step 4 by centrifugation until a heavy layer containing fibers and a light layer containing proteins are obtained;

[0016] 6) Add polysorbate to the hydrolyzed protein-rich suspension of step 4 or optionally to the light layer containing proteins of step 5;

[0017] 7) Separate the polysorbate-containing protein-rich suspension or the light layer containing proteins of step 6 by centrifugation into a heavy layer containing proteins and a light layer containing soluble compounds including lipids; and

[0018] 8) Optionally dry the heavy layer containing the protein of step 7.

[0019] The third and last embodiment is the industrial use of the protein composition of the present invention, preferably in the fields of food, feed, medicine and cosmetics.

[0020] The present invention will be better understood from the following detailed description. Detailed Description

[0022] The first embodiment of the present invention is an oat protein composition, characterized in that the composition does not contain trace organic solvents, has a residual lipid content of less than 10% by weight based on the total dry weight of the oat protein composition in dry matter, and has an average particle size greater than 10 microns.

[0023] The so-called "composition that does not contain trace organic solvents" refers to a composition containing less than 100 ppm of solvent, preferably less than 10 ppm of organic solvent, and more preferably a composition that does not contain organic solvent at all.

[0024] The so-called "organic solvent" refers to a solvent based on a carbon-containing compound. In the opposite case, the inorganic solvents allowed in the present invention do not contain carbon. A typical inorganic solvent allowed in the present invention is water.

[0025] "Oat" in the present application must be understood as a cereal plant belonging to the genus Avena. This genus can be divided into wild species and cultivated species, which have been cultivated for thousands of years as a food source for humans and livestock. The cultivated species include:

[0026] - Avena sativa - the most cultivated species, commonly known as "oat".

[0027] - Avena abyssinica – Native to Ethiopia, Eritrea, and Djibouti; transplanted to Yemen and Saudi Arabia

[0028] - Avena byzantina, a minor crop in Greece and the Middle East; introduced to Spain, Algeria, India, New Zealand, South America, etc.

[0029] - Avena nuda – Hulless oats or naked oats, which have the same role in Europe as Avena abyssinica in Ethiopia. It is sometimes included in Avena sativa and is widely grown in Europe, and then replaced by oats. Due to its slightly better nutrient content than common oats, the importance of Avena nuda has increased in recent years, especially in organic agriculture.

[0030] - Avena strigosa – Abnormal oats, rough oats or black oats, grown in some areas of Western Europe and Brazil for feed.

[0031] In a preferred embodiment, oats in this application must be understood as Avena nuda, hulless oats or naked oats.

[0032] In a preferred embodiment, the oat protein composition is a protein concentrate or a protein isolate. Thus, based on the total dry weight of the oat protein composition on a dry matter basis, the oat protein composition may have about 40% by weight or more of protein, for example, about 40% to 85%.

[0033] In this application, "protein concentrate" must be understood as an oat protein composition containing 40% to 70% by weight, preferably 50% to 60% by weight, of protein based on the total dry weight of the oat protein composition on a dry matter basis.

[0034] In this application, "protein isolate" must be understood as an oat protein composition containing more than 70% by weight, preferably more than 80% by weight, of protein based on the total dry weight of the oat protein composition on a dry matter basis.

[0035] Various schemes of the prior art can be used to quantify the protein content. In this application, the preferred method for quantifying the protein content includes 1) analyzing the nitrogen content in the composition using the Kjeldhal method and 2) multiplying the nitrogen content by a factor of 6.25 (which represents the average amount of nitrogen in proteins).

[0036] In the present application, "protein" must be understood as a molecule consisting of one or more long chains of amino acid residues. In the present application, the protein can be a natural protein or a modified protein, including hydrolyzed proteins. These proteins can be present in different concentrations, including protein isolates or protein concentrates. Oats are the only cereal containing avenalin as a globulin or legumin as the main storage protein (80% by weight). Globulins are characterized by their solubility in dilute salt solutions, which is contrary to more typical cereal proteins, such as glutenin and zein (which are prolamins). The minor protein of oats is the prolamin called avenin.

[0037] In the present application, "lipid" must be understood as a molecule soluble in non-polar solvents. Lipids include fatty acids, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E, and K), monoglycerides, diglycerides, triglycerides, and phospholipids. Oats, after corn, have the highest lipid content among all cereals, i.e., greater than 10% by weight for some oats and up to 17% by weight for some corn varieties, compared to approximately 2% - 3% by weight for wheat and most other cereals. The polar lipid content of oats (about 8% - 17% glycolipids and 10% - 20% phospholipids or about 33% total polar lipid content) is greater than that of other cereals because most of the lipid fraction is contained in the endosperm.

[0038] To quantify the residual lipids, various methods well-known to those skilled in the art can be used. Preferably, Test A based on the CEM method is used. The CEM method is based on NMR analysis and gives the extractable lipid content. In Test A based on the CEM method, the sample is simply introduced into the device, and the analysis is started according to the user manual and the results are obtained very quickly.

[0039] The oat protein composition advantageously exhibits an average particle size greater than 20 microns, preferably greater than 30 microns, more preferably greater than 40 microns. The oat protein composition advantageously exhibits an average particle size less than 300 microns, preferably less than 200 microns, more preferably less than 150 microns.

[0040] Based on the total dry weight of the oat protein composition on a dry matter basis, the oat protein composition can contain 0.1% - 10% by weight, preferably 0.5% - 6% by weight, more preferably 1% - 4% by weight of starch. The starch content of the composition can be determined using AOAC Official Method 996.11, Starch in Cereal Products (Total).

[0041] Based on the total dry weight of the oat protein composition on a dry matter basis, the oat protein composition may contain from 0.1% to 10% by weight, preferably from 0.5% to 6% by weight, more preferably from 1% to 4% by weight of total dietary fiber of fiber. In the present application, the fiber content can be determined using AOAC Official Method 2017.16, Total Dietary Fiber in Foods and Food Products. One dietary fiber present in the dietary fiber usually present in the composition is β-glucan.

[0042] Based on the total weight of the protein in the composition, the oat protein composition may contain less than 50% of proteins with a molecular weight of 10 kDa and smaller, advantageously less than 30%, preferably less than 10%. In one embodiment, based on the total weight of the protein in the composition, the oat protein composition comprises:

[0043] - from 0.5% to 30% of proteins with a molecular weight of 300 kDa and larger, advantageously from 5% to 15%,

[0044] - from 30% to 75% of proteins with a molecular weight between 50 kDa and 300 kDa, advantageously from 45% to 65%,

[0045] - from 10% to 50% of proteins with a molecular weight between 10 kDa and 50 kDa, advantageously from 25% to 45%,

[0046] - from 0.5% to 20% of proteins with a molecular weight of 10 kDa and smaller, advantageously from 1% to 10%,

[0047] with a sum total of 100%.

[0048] An advantage of this preferred embodiment of the invention is that, compared to low molecular weight oat protein compositions, the molecular weight of the oat protein composition is high, which can provide different protein functions, such as those described, for example, in the document Brückner-Gühmann et al.

[0049] The protein molecular weight (MW) distribution can be determined using size exclusion chromatography. The protocol for preparing the sample to be analyzed and measuring using size exclusion chromatography is included in the following Examples section.

[0050] In the present application, "particle size" must be understood as a concept introduced for comparing the sizes of solid, liquid or gaseous particles. The particle size distribution (PSD) of a powder, granular material or particles dispersed in a fluid is a list of values or a mathematical function that defines the relative amounts of particles present according to size, usually by mass. Several methods can be used to measure particle size and particle size distribution. Some of these methods are based on light, or ultrasound, or an electric field, or gravity or centrifugation. Using sieves is a common measurement technique. In the present application, the laser diffraction method is preferred. As for the "average particle size" (d50) determined by laser diffraction, this average particle size is a volume-weighted average particle size. A person skilled in the art will be able to select the laser diffraction method, which will allow him to obtain an accurate determination of the average particle size. Examples of such methods are indicated in the Examples section.

[0051] In the present application, "dry matter" must be understood as the relative weight percentage of solids based on the total weight of the sample. Each well-known method can be used, but the drying method is preferred, which consists of estimating the amount of water by heating a known amount of the sample. In the drying method:

[0052] - Prepare the sample and weigh its mass: m 1 (g),

[0053] - Place the sample in an oven to allow the water to evaporate until the sample mass stabilizes. Preferably, during this step, the temperature is 105 °C at normal atmospheric pressure.

[0054] - Weigh the final sample: m 2 (g)

[0055] - Calculate the dry matter according to the following formula: dry matter = (m 2 / m 1 ) * 100.

[0056] The second embodiment of the present invention is a method for producing an oat protein composition, based on the total dry weight of the oat protein composition in dry matter, the oat protein composition having a residual lipid content of less than 10% by weight, the oat protein composition may be the oat protein composition as defined above, characterized in that the method comprises the following steps:

[0057] 1) Prepare oat seeds or provide protein-rich oat flour;

[0058] 2) In the case of using oat seeds in step 1, grind the oat seeds of step 1 until a protein-rich flour is obtained;

[0059] 3) Mix the protein-rich flour of step 1 or 2 with water until a protein-rich suspension is obtained;

[0060] 4) Add amylase to the protein-rich suspension of step 3 to hydrolyze the protein-rich suspension;

[0061] 5) Optionally separate the hydrolyzed protein-rich suspension of step 4 by centrifugation until a heavy layer containing fibers and a light layer containing proteins are obtained;

[0062] 6) Add polysorbate to the hydrolyzed protein-rich suspension of step 4 or optionally to the light layer containing proteins of step 5;

[0063] 7) Separate the polysorbate-containing protein-rich suspension or the light layer containing proteins of step 6 by centrifugation into a heavy layer containing proteins and a light layer containing soluble compounds including lipids; and

[0064] 8) Optionally dry the heavy layer containing the protein of step 7.

[0065] Thus, the method of the present invention does not use organic solvents and allows the obtaining of a composition free of traces of organic solvents.

[0066] The first step aims to provide oat seeds in a state allowing further steps. Oat seeds can be cultivated and / or commercially available. Then the oat seeds can be prepared, including possible sieving or dehulling steps.

[0067] Before use, the oat seeds can be dry-heated or wet-heated. The purpose of dry-heating or wet-heating is to destroy enzymes, including β-glucanase, lipase and lipoxygenase. In fact, the inactivation of lipase and lipoxygenase is indicated to prevent the product from becoming putrid. In the method of the present invention, heat treatment (especially steaming) should be avoided or at least kept as short as possible and / or carried out at as low a temperature as possible to keep the denaturation of oat proteins low.

[0068] The preferred raw materials for preparing oat seeds in step 1 in the present invention are naked oats, hulless oats or hull-less oats, or dry-milled oat flour that have not been heat-treated, especially not steamed. However, wet-milled oat flour that has not been heat-treated or dry-milled oat flour of any oat fraction can also be used. Particularly preferred raw materials are dry-milled non-heat-treated oats, non-heat-treated oat bran or non-steamed oats.

[0069] The second step aims to grind oat seeds in order to obtain protein-rich flour. To grind oat seeds, all well-known common techniques can be used, including stone mills, roller mills or knife mills. In this step, the preferred particle size distribution of the resulting protein-rich flour can be a D50 (50th percentile) above 30 microns, preferably above 40 microns, and even more preferably above 50 microns. In the present invention, the D50 is measured with the help of any technique known to those skilled in the art. In a preferred manner, laser granulometry is preferred.

[0070] Based on the dry solid content of the protein powder, the protein-rich flour can contain a protein content above 14%, for example above 16%.

[0071] Preferably, based on the dry solid content of the protein powder, the content of insoluble fiber in the protein-rich flour is less than 4%, preferably less than 2%. Within these preferred ranges, the viscosity is lower during the process, which makes the process easier to carry out.

[0072] Instead of steps 1 and 2, commercial oat flour can be used directly. This alternative embodiment allows for the combination of steps 1 and 2 according to claim 1, which are completed by a third party, and a quick start in step 3.

[0073] The third step aims to obtain a protein-rich suspension, which is an oat flour suspension. As water, each type of food-compatible water can be used, but tap water and de-carbonated water are preferred. The aim of this third step is to achieve a dry matter content included between 5% and 20% by weight, preferably between 10% and 15% by weight, and most preferably between 10% and 13% by weight, relative to the total weight of the suspension. Preferably, in step 3, the flour can be weighed and introduced into a tank containing water and equipped with agitation, pH and heating devices. Preferably, during step 3, the temperature is adjusted between 60 °C and 80 °C, preferably between 65 °C and 75 °C. Preferably, during step 3, the pH is adjusted to between 5 and 6, preferably 5.5. In the present application, the pH can be adjusted by adding well-known acidic or basic compounds such as hydrochloric acid, sodium hydroxide, citric acid, calcium hydroxide and potassium hydroxide. Agitation can be set to obtain a homogeneous suspension without foaming.

[0074] The fourth step aims to hydrolyze the starch contained in the protein-rich suspension with the help of amylase. Amylase is a class of enzymes that catalyze the hydrolysis of starch molecules into smaller sugar molecules. In step 4 of the present application, each type of amylase (such as β-amylase or amyloglucosidase) can be used, but α-amylase is preferred. In a preferred embodiment, heat-resistant α-amylase is preferred.

[0075] The purpose of step 4 is to effectively reduce the size of the starch contained in the protein-rich suspension by hydrolysis, thereby obtaining soluble dextrin or glucose syrup rather than starch. This soluble conversion of starch will allow for simpler separation from insoluble compounds in the subsequent steps. However, as illustrated below, based on the total dry weight of the protein composition, such separation known from the prior art cannot effectively obtain a protein composition having less than 10% by weight of lipids.

[0076] In a preferred embodiment, α-amylase is preferred. The activity of α-amylase is expressed as KNU units. In fact, ethylidene-G7-PNP (4,6-ethylidene(G7)-p-nitrophenyl(G1)-α,D-maltoheptoside) is used as a substrate to measure the α-amylase activity. The compound is hydrolyzed by LE399 α-amylase into G2-PNP and G3-PNP, where G means glucose and PNP means p-nitrophenol. G2-PNP and G3-PNP are then hydrolyzed by α-glucosidase added to the reaction mixture into glucose and p-phenol. Under standard reaction conditions, the absorbance is measured spectrophotometrically at 409 nm. One KNU(T) corresponds to the amount of α-amylase that hydrolyzes 672 micromoles of ethylidene-G7PNP per minute under standard conditions (pH 7.1, 37 °C). The quantitative limit of this method is about 0.3 KNU(T) / g. In step 4, the amylase added in step 4 can have an activity level including between 100 KNU / 100 g and 170 KNU / 100 g of flour, preferably between 110 KNU / 100 g and 160 KNU / 100 g of flour, even more preferably between 120 KNU / 100 g and 150 KNU / 100 g of flour. In other words, the amount of α-amylase units introduced to hydrolyze starch includes between 100 KNU / 100 g and 170 KNU / 100 g of flour, preferably between 110 KNU / 100 g and 160 KNU / 100 g of flour, even more preferably between 120 KNU / 100 g and 150 KNU / 100 g of flour. One thousand Novo α-amylase units (KNU) is a value known to those skilled in the art and is the amount of enzyme that decomposes a determined amount of starch per hour in the Novozymes standard method. This test involves determining the α-amylase activity relative to an α-amylase standard (Termamyl) of known activity and is expressed in thousand Novo α-amylase units (KNU). One KNU is the amount of α-amylase that dextrinizes 5.26 g of starch dry matter per hour under standard conditions (pH 7.1, 37 °C).

[0077] The fifth step includes optionally centrifuging the heavy layer containing the fibers and the light layer containing the proteins. In fact, since the fibers and the starch are insoluble and heavier than the proteins, sugars, and salts, they will be separated by means of a centrifuge, which preferably operates between 3000G and 4000G.

[0078] As illustrated below, after step 5, more than 70% of the dry matter obtained, preferably more than 80% of the dry matter, consists of proteins.

[0079] The sixth step includes adding polysorbate.

[0080] Polysorbate is a class of emulsifiers used in cosmetic, pharmaceutical, and food formulations. Polysorbate is an oily liquid derived from ethoxylated sorbitol (sorbitol derivative) esterified with fatty acids. Common trade names for polysorbate include Scattics, Alkest, Canarcel, and Tween. Commonly used polysorbates are polysorbate 20 (polyoxyethylene (20) sorbitan monolaurate), polysorbate 40 (polyoxyethylene (20) sorbitan monopalmitate), polysorbate 60 (polyoxyethylene (20) sorbitan monostearate), and polysorbate 80 (polyoxyethylene (20) sorbitan monooleate) (the number after "polyoxyethylene" refers to the total number of oxyethylene-(CH2CH2O)-groups present in the molecule, and the number after "polysorbate" is related to the type of fatty acid associated with the polyoxyethylene sorbitol part of the molecule). Preferably, the polysorbate is polysorbate 80 (polyoxyethylene (20) sorbitan monooleate), also known as Tween 80.

[0081] After the hydrolysis in step 4 and optionally after the removal of the internal fibers in step 5, and before adding the polysorbate in step 6, the pH can be adjusted to between 5.5 and 7.5, preferably 6.5. In step 6, the polysorbate can be added at a temperature including between 50°C and 80°C, preferably between 55°C and 75°C, and even more preferably 65°C.

[0082] Relative to the total weight of the protein-rich flour that is oat flour, the polysorbate can be added in a percentage including between 0.5% by weight and 5% by weight, preferably between 2% by weight and 4% by weight, and more preferably 3% by weight.

[0083] Polysorbate 80 is preferred, and an example of a commercial polysorbate 80 is Tween 80 from Croda.

[0084] Then the medium can be agitated with stirring, and preferably stirred for an average of one hour.

[0085] The seventh step involves centrifugation, thereby allowing the protein-rich suspension to be separated into a heavy layer mainly containing proteins and a light layer containing other compounds including lipids.

[0086] In a preferred embodiment, during step 7, the pH is first adjusted to between 4 and 6, preferably 6. By adjusting the pH at this range, the proteins will coagulate. In a preferred embodiment, heat can also be applied to assist coagulation. In this case, the temperature will be set between 40°C and 70°C, preferably between 50°C and 60°C. In all embodiments, the duration of step 7 is selected to achieve sufficient coagulation. Preferably, the duration of step 7 is set between 30 minutes and 2 hours, preferably between 45 minutes and 1 hour. Then the culture medium is fed into a centrifuge, which can operate between 3000G and 4000G. The precipitate, lower fraction or heavy layer containing proteins is collected. The supernatant, upper layer or light layer containing hydrolyzed starch and lipids is discarded.

[0087] In a preferred embodiment, the precipitate, lower fraction or heavy layer is mixed with water, agitated and then fed into a second centrifuge, which can operate between 3000G and 4000G. Again, the precipitate, lower fraction or heavy layer containing proteins is collected. The supernatant, upper layer or light layer containing hydrolyzed starch and lipids is discarded.

[0088] In the final optional eighth step, the oat proteins concentrated in the precipitate, lower fraction or heavy layer can be dried. To do this, a person skilled in the art can preferably use a spray dryer, preferably a multi-stage spray dryer. This will allow an oat protein composition with the average particle size defined above to be provided. Before spray drying, homogenization and UHT treatment steps can also be carried out.

[0089] The third and final embodiment of the present invention is the use of the protein composition of the present invention or the protein composition obtained by the method of the present invention, preferably in the fields of food, feed, medicine and cosmetics.

[0090] Such an oat protein composition is particularly suitable for ready-to-drink, beverages, and baking. Its low lipid content allows for an improved sensory experience during formulation, as the low lipid content and in the presence of oxygen, undesirable compounds cannot alter its sensory quality.

[0091] The present invention will be better understood by the following non-exhaustive examples.

[0092] Examples

[0093] Method for Determining MW Distribution :

[0094] Dissolve the sample in 200 mM phosphate buffer, pH = 7.6, vortex initially for 1 minute and later for 10 minutes and store overnight at 4 °C. Centrifuge the solution at 7000 g for 10 minutes, measure the soluble protein content of the supernatant the next day, and dilute the sample to 10 mg / mL with phosphate buffer.

[0095] Use 2 SEC columns (400 and 300 Agilent Advanced Bio SEC columns, 5000 - 1,250,000 MW range) and chromatograph the sample sequentially using phosphate buffer, pH = 7.6 as the mobile phase at 0.5 mL / min. Detection is at UV = 280 nm.

[0096] Analyze several protein molecular weight standards (lysozyme, carbonic anhydrase, BSA, HSA, B - amylase, apoferritin, thyroglobulin) from 14300 Da to 669000 Da to identify retention times and calibrate the chromatographic equipment.

[0097] For sample analysis, determine the chromatographic peak or peak apex (group) and the range of the peak (start and end), and determine the molecular weight for the range and peak apex. The molecular weight percentages are determined as: >300 kDa, 300 kDa to 50 kDa, 50 kDa to 10 kDa, and <10 kDa.

[0098] Example 1: Prior Art Method Involving Starch Hydrolysis

[0099] Weigh 2.5 kg of No. 70 oat flour, from Grain Millers, batch number 1802150. Fill the feed tank with 25 L of water at 40 °C - 50 °C. Mix the flour into the water. Adjust the pH to 5.4 to 5.5 with 1 N HCl while agitating for 10 minutes. Add 25 g of Liquozyme supra (from Novozyme). Heat on a hot plate at 70 °C, 300 rpm for 2 hours. Lower the pH to 5.0 with 1 N HCl and stir for 30 minutes. Feed through a Lemitec centrifuge at 500 mL / min, 580 G, 10 rpm differential. Add 12.5 L of 50 °C water to the curd. Adjust the pH to 5.0 with 1 N HCl. Feed through a Lemitec at 500 mL / min, 3600 rpm, 10 rpm differential. Dry the washed curd with a spray dryer.

[0100] The sample is designated as "S1: Prior art without polysorbate"

[0101] Example 2: Method of the Invention Involving Starch Hydrolysis and Use of Polysorbate

[0102] Weigh 2.5 kg of oat flour No. 70 from Grain Millers, batch number 1802150. Fill the feed tank with 25 L of water at 40 °C - 50 °C. Mix the flour into the water. Adjust the pH to 5.4 to 5.5 with 1N HCl while stirring for 10 minutes. Add 25 g of Liquozyme supra (from Novozyme). Heat on a hot plate at 70 °C, 300 rpm for 2 hours. Add 75 g of Tween 80. Adjust the pH to 6.5 and allow to cool to 65 °C, holding for 60 minutes. Lower the pH to 5.0 with 1N HCl and stir for 30 minutes. Feed through a Lemitec centrifuge at 500 mL / min, 580G, 10 rpm differential. Add 12.5 L of 50 °C water to the curd. Adjust the pH to 5.0 with 1N HCl. Feed through Lemitec at 500 mL / min, 3600 rpm, 10 rpm differential. Dry the washed curd with a spray dryer.

[0103] The sample is designated as "S2: Invention with Polysorbate".

[0104] Example 3: Importance of Selecting Polysorbate as Surfactant

[0105] Compare the polysorbate with sodium dodecyl sulfate (another well-known food surfactant).

[0106] Weigh 2.5 kg of oat flour No. 70 from Grain Millers, batch number 1802150. Fill the feed tank with 25 L of water at 40 °C - 50 °C. Mix the flour into the water. Adjust the pH to 5.4 to 5.5 with 1N HCl while stirring for 10 minutes. Add 25 g of Liquozyme supra (from Novozyme). Heat on a hot plate at 70 °C, 300 rpm for 2 hours. Add 75 g of SDS. Adjust the pH of the SDS sample to 6, allow to cool to 65 °C, holding for 60 minutes. Lower the pH to 5.0 with 1N HCl and stir for 30 minutes. Feed through a Lemitec centrifuge at 500 mL / min, 580G, 10 rpm differential. Add 12.5 L of 50 °C water to the curd. Adjust the pH to 5.0 with 1N HCl. Feed through Lemitec at 500 mL / min, 3600 rpm, 10 rpm differential. Dry the washed curd with a spray dryer.

[0107] The sample is designated as "S3: Comparative Example with SDS".

[0108] Example 4: Importance of Reacting with Polysorbate Parameters

[0109] Weigh 2.5 kg of oat flour No. 70 from Grain Millers, batch number 1802150. Fill the feed tank with 25 L of water at 40 °C - 50 °C. Mix the flour into the water. Adjust the pH to 5.4 to 5.5 with 1N HCl while stirring for 10 minutes. Add 25 g of Liquozyme supra (from Novozyme). Heat on a hot plate at 70 °C, 300 rpm for 2 hours. Add 75 g of Tween 80. Adjust the pH to 6.5 and allow to cool to 35 °C, holding for 60 minutes. Lower the pH to 5.0 with 1N HCl and stir for 30 minutes. Feed through a Lemitec centrifuge at 500 mL / min, 580G, 10 rpm differential. Add 12.5 L of 50 °C water to the curd. Adjust the pH to 5.0 with 1N HCl. Feed through a Lemitec at 500 mL / min, 3600 rpm, 10 rpm differential. Dry the washed curd with a spray dryer.

[0110] The sample is designated as "S4: Polysorbate treatment under sub - optimal conditions"

[0111] Example 5: Preferred Embodiment of Using Fiber Centrifugation before Using Polysorbate

[0112] Weigh 2.5 kg of oat flour No. 70 from Grain Millers. Fill the feed tank with 25 L of water at 40 °C - 50 °C. Mix the flour into the water. Adjust the pH to 5.4 to 5.5 with 1N HCl while stirring for 10 minutes. Add 25 g of Liquozyme supra (from Novozyme). Heat on a hot plate at 70 °C, 300 rpm for 2 hours. Adjust the pH to 7.0 with 1N NaOH. Centrifuge with a Lemitec centrifuge at 580G, 10 rpm, 500 ml / min, with a 60 / 10 weir differential. Add 75 g of Tween 80 to the overflow. Adjust the pH to 6, allow to cool to 65 °C, holding for 60 minutes. Lower the pH to 5.0 with 1N HCl. Feed through a Lemitec centrifuge at 580G, 3600 rpm, 10 rpm differential. Add 12.5 L of 50 °C water to the curd. Adjust the pH to 5.0 with 1N HCl. Feed through a Lemitec at 500 mL / min, 3600 rpm, 10 rpm differential. Dry the washed curd with a spray dryer.

[0113] The sample is designated as "S5: Fiber centrifugation before using polysorbate"

[0114] Example 6: Comparison of Previous Examples

[0115] The results are presented in Table 1 below. In Table 1, percentages are expressed as weight percentages using the above method.

[0116] D50 was measured by a laser particle size analyzer (Mastersizer 3000, from Malvern), which measures the intensity of scattered light over a range of scattering angles on dry powder without a dispersion buffer using forward scattering measurement, and uses the software of the device with a Mie scattering model to fit the distribution to the measured scattering pattern.

[0117] [Table 1]

[0118]

[0119] Example 7: Production of Oat Protein Composition on Pilot Scale

[0120] The protein composition was produced using the following protocol:

[0121] Weigh 12.5 kg of oat flour (No. 70, Grain miller), fill a 50 - gallon jacketed tank with approximately 88 L of water at 50 °C, and mix the flour into the water, adjusting to reach 12% solids. Adjust the pH to 5.4 - 5.5 with HCl while agitating for 10 minutes, and add 125 g of Liquozyme supra (from Novozymes). Heat to 70 °C using a recirculation pump with a heat exchanger over a 2 - hour period. Then adjust the pH to 7.0 with NaOH and centrifuge at 5000 rpm, 10 rpm, 2000 ml / min differential, feed at 60 / 10 weir to a Lemitec decanter centrifuge, and collect the overflow in a 50 - gallon tank. Add 210 g of a 30% solution of Tween 80 to the tank (62.5 g of pure T80) and heat to 65 °C and hold for 60 minutes. Fill the tank with water to a certain volume, heat back to 60 °C and lower the pH to 5.0 with HCl. Centrifuge on a Clara 20 disc centrifuge at 0.45 m 3 / h, 9,000 rpm. Resuspend the underflow fraction in a 50 - gallon jacketed tank, fill with water to a certain volume and heat to 60 °C, repeat the centrifugation step and store the underflow fraction in a 5 - gallon bucket in the refrigerator overnight. Heat to 40 °C, adjust to pH 7.0 and pass through an ultra - high temperature device (maintain the temperature at 154 °C, flash temperature at 71 °C, hold time of 15 s (380 ml / min, pp speed 200, long cycle). Dry with a spray dryer.

[0122] The oat protein composition contains 82.8% protein, 6.1% lipids, 1.5% insoluble fiber, 1.6% soluble fiber, 1.7% β-glucan, and 3.3% moisture. The starch content was determined to be approximately 2% - 3%. The MW distribution is shown in Table 2 below.

[0123] Table 2 :

[0124]

Claims

1. Oat protein composition, characterized in that, said composition comprises, based on the total dry weight of said composition on a dry matter basis: 40% to 70% by weight of oat protein, or more than 70% by weight of oat protein; and based on the total weight of the oat protein in said composition: 5% to 15% of proteins with a molecular weight of 300 kDa and greater, 45% to 65% of proteins with a molecular weight between 50 kDa and 300 kDa, 25% to 45% of proteins with a molecular weight between 10 kDa and 50 kDa, 1% to 10% of proteins with a molecular weight of 10 kDa and less, the sum being 100%, and said composition does not contain trace organic solvents, has a residual lipid content of less than 10% by weight based on the total dry weight of said oat protein composition on a dry matter basis, and has an average particle size (d50) greater than 10 microns and less than 300 microns as determined by laser diffraction.

2. The oat protein composition according to claim 1, wherein based on the total dry weight of said oat protein composition on a dry matter basis, said composition comprises 50% to 60% by weight of oat protein.

3. The oat protein composition according to claim 1, wherein based on the total dry weight of said oat protein composition on a dry matter basis, said composition comprises more than 80% by weight of oat protein.

4. The oat protein composition according to claim 1, wherein based on the total dry weight of said oat protein composition on a dry matter basis, said composition comprises 0.1% to 10% by weight of starch.

5. The oat protein composition according to claim 4, wherein based on the total dry weight of said oat protein composition on a dry matter basis, said composition comprises 0.5% to 6% by weight of starch.

6. The oat protein composition according to claim 5, wherein based on the total dry weight of said oat protein composition on a dry matter basis, said composition comprises 1% to 4% by weight of starch.

7. The oat protein composition according to claim 1, wherein based on the total dry weight of said oat protein composition on a dry matter basis, said composition comprises 0.1% to 10% by weight of total dietary fiber of fiber.

8. The oat protein composition according to claim 7, wherein based on the total dry weight of said oat protein composition on a dry matter basis, said composition comprises 0.5% to 6% by weight of total dietary fiber of fiber.

9. The oat protein composition according to claim 8, wherein based on the total dry weight of said oat protein composition on a dry matter basis, said composition comprises 1% to 4% by weight of total dietary fiber of fiber.

10. The oat protein composition according to claim 1, wherein said composition exhibits: - an average particle size greater than 20 microns; and - an average particle size less than 200 microns.

11. The oat protein composition according to claim 10, wherein said composition exhibits: - an average particle size greater than 30 microns; and - an average particle size less than 200 microns.

12. The oat protein composition according to claim 11, wherein the composition exhibits: - an average particle size greater than 40 microns; and - an average particle size less than 150 microns.

13. A method for producing the oat protein composition according to any one of claims 1 to 12, characterized in that the method comprises the following steps: 1) preparing oat seeds or providing protein-rich flour; 2) in the case of using oat seeds in step 1, grinding the oat seeds of step 1 until protein-rich flour is obtained; 3) mixing the protein-rich flour of step 1 or 2 with water until a protein-rich suspension is obtained; 4) adding amylase to the protein-rich suspension of step 3 to hydrolyze the protein-rich suspension; 5) separating the hydrolyzed protein-rich suspension of step 4 by centrifugation until a heavy layer containing fibers and a light layer containing proteins are obtained; and, 6A) adding polysorbate to the light layer containing proteins of step 5 at a temperature between 50 °C and 80 °C, wherein after hydrolysis in step 4 and after removing internal fibers, the pH is adjusted to between 5.5 and 7.5 before adding the polysorbate; Or, 6B) adding polysorbate to the hydrolyzed protein-rich suspension of step 4 at a temperature between 50 °C and 80 °C, wherein after hydrolysis in step 4, the pH is adjusted to between 5.5 and 7.5 before adding the polysorbate; 7) separating the protein-rich suspension or the light layer containing proteins containing polysorbate of step 6A or step 6B by centrifugation into a heavy layer containing proteins and a light layer containing soluble compounds including lipids, wherein the pH is first adjusted to between 4 and 6.

14. The method according to claim 13, wherein in step 6A or step 6B, the pH is adjusted to 6.5 before adding the polysorbate.

15. The method according to claim 13, further comprising: 8) drying the heavy layer containing proteins of step 7.

16. The method according to claim 13, wherein in step 6A or step 6B, polysorbate is added at a temperature between 55 °C and 75 °C.

17. The method according to claim 16, wherein in step 6A or step 6B, polysorbate is added at a temperature of 65 °C.

18. The method according to claim 13, wherein the amylase in step 4 is a heat-resistant amylase.

19. The method according to claim 13, wherein the amylase added in step 4 has an activity level between 100 KNU / 100 g and 170 KNU / 100 g of flour.

20. The method according to claim 19, wherein the amylase added in step 4 has an activity level between 110 KNU / 100 g and 160 KNU / 100 g of flour.

21. The method according to claim 20, wherein the amylase added in step 4 has an activity level ranging from 120 KNU / 100 g to 150 KNU / 100 g of flour.

22. Use of the protein composition according to any one of claims 1 to 12 in the fields of food, feed, pharmaceuticals and cosmetics.

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