Oat protein composition with low lipid content and no traces of organic solvents

Abstract

The present invention relates to the field of oat protein compositions and methods for producing the same. In particular, the present invention relates to oat protein compositions having a low lipid content and containing no traces of organic solvents, and methods for producing the same.

Description

[Technical field]

[0001] The present invention relates to the field of oat protein compositions and methods for producing the same. In particular, the present invention relates to oat protein compositions having a low lipid content and no traces of organic solvents and methods for producing the same. [Background technology]

[0002] Oats are a well-known source of a wide variety of useful products. Examples of such products include flours, starches, protein isolates and concentrates, protein-enriched flours, brans, gums, and oils. Conventional techniques used in the cereal grain processing industry are often difficult to use with oats due to process problems associated with the lipids present in oats. Furthermore, unless oats are defatted before milling, the milling process produces lipid-containing flour and protein fractions, which can lead to rancidity during storage of the flour and protein.

[0003] The most widely used technique consists of primary defatting with organic solvents such as hexane or ethanol. The skilled artisan knows the example of DuPont's European Patent No. 0051943, 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 risks of explosion and spoilage, and the residual levels of lipids in the final product.

[0004] Such risks appear to be significant, and the main current commercial product, called PROATEIN®, is currently produced without defatting. EP 1706001 is based solely on the use of amylase and centrifugation. As disclosed in the Examples section, such processes result in compositions with lipid contents of more than 10% by weight, based on the total weight.

[0005] To address these shortcomings, several alternative processes have been proposed recently. Such processes are based on the use of supercritical CO2. Those skilled in the art are aware of EP 2120604 to VALTION TEKNILLINEN. However, to reach a high level of defatting, the flour needs to be processed and milled, which results in an average protein particle size of less than 10 microns (see paragraph 0047 of EP 2120604). This process results in an ultra-fine size protein powder that is undesirable for some applications, and which is also difficult to handle in industrial facilities, mainly due to dust formation and explosion hazards. Another major industrial problem associated with particles with a size less than 10 microns is that the cyclone and filtration systems required to recover such small particles are expensive and difficult to operate efficiently and / or effectively.

[0006] US Patent Application Publication No. 2009 / 0155444(A1) discloses extrudates made from soy protein and oat flour. It does not describe an oat protein composition.

[0007] The document by Bruckner-Guhmann et al. (Foarming characteristics of oat protein and modification by partial hydrolysis, European Food Research and Technology, Vol. 244, no12, 28 August 2018, pages 2095-2106) describes the production of an oat protein isolate using an oat protein concentrate as starting material, alkaline extraction of this concentrate, separation of the protein in a supernatant, and freeze-drying this supernatant to produce a protein isolate flour. The paper studies the foaming functionality of the protein isolate obtained. The document does not disclose the average particle size of the obtained oat protein composition.

[0008] The aim of the present patent application is to overcome these problems and therefore propose a new process which improves upon the existing techniques in the prior art, thereby resulting in a unique oat protein flour. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0010] A second embodiment is a process for producing an oat protein composition having a residual lipid content of less than 10% by weight on dry matter, based on the total dry weight of the oat protein composition, which is the oat protein composition of the invention as defined above, comprising the following steps: 1) providing oat seeds or providing a protein-rich flour; 2) if oat seeds are used in step 1, grinding the oat seeds of step 1 until a 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 an amylase enzyme to the protein-rich suspension of step 3 to hydrolyze the protein-rich suspension; 5) Optionally, separating the hydrolyzed protein-rich suspension of step 4 by centrifugation until a heavy layer containing fiber and a light layer containing protein are obtained; 6) adding polysorbate to the hydrolyzed protein-rich suspension of step 4 or, optionally, to the protein-containing light phase of step 5; 7) centrifuging the polysorbate-containing protein-rich suspension or the protein-containing light layer of step 6 to separate it into a protein-containing heavy layer and a lipid-containing soluble compound-containing light layer; and 8) Optionally, drying the protein-containing heavy layer from step 7.

[0011] The third and final embodiment is the industrial use of the protein composition of the invention, preferably in the food, feed, pharmaceutical and cosmetic sectors.

[0012] For a better understanding of the present invention, the following detailed description is provided. Detailed Description of the Preferred Embodiments

[0013] A first embodiment of the present invention is an oat protein composition characterised in that the composition does not contain any traces of organic solvents, has a residual lipid content of less than 10% by weight on dry matter, based on the total dry weight of the oat protein composition, and has an average particle size of more than 10 microns.

[0014] By "a composition that does not contain any traces of organic solvent" is meant a composition that contains less than 100 ppm of solvent, preferably less than 10 ppm of organic solvent, and more preferably a composition that does not contain any organic solvent.

[0015] By "organic solvent" is meant a solvent based on compounds containing carbon. In contrast, inorganic solvents acceptable in the present invention do not contain carbon. A typical inorganic solvent acceptable in the present invention is water.

[0016] By "oats" in this application it is to be understood a cereal plant belonging to the plant genus Avena. This genus can be divided into wild species and cultivated species that have been cultivated for thousands of years as a food source for humans and livestock. The cultivated species include: Avena sativa - the most cultivated species, commonly called "oats." Avena abyssinica - Ethiopian oat, native to Ethiopia, Eritrea, and Djibouti; endemic to Yemen and Saudi Arabia Avena byzantina, by-crop in Greece and the Middle East; introduced in Spain, Algeria, India, New Zealand, South America, etc. Avena nuda - Naked oat or shellless oat, used in Europe as Avena sativa in Ethiopia. It is sometimes included in A. sativa and was widely cultivated in Europe before being replaced by the latter. Its nutrient content is somewhat better than that of common oat, so A. nuda has become increasingly important in recent years, especially in organic farming. Avena strigosa - brome, bristle oat, or black oat, grown for animal feed in parts of Western Europe and Brazil.

[0017] In a preferred embodiment, oats are to be understood in the present application as Avena nuda, ie naked oats or hullless oats.

[0018] In a preferred embodiment, the oat protein composition is a protein concentrate or a protein isolate, and thus has about 40% or more protein by weight on dry matter, for example about 40-85%, based on the total dry weight of the oat protein composition.

[0019] In the present application, a "protein concentrate" is to be understood as an oat protein composition which contains 40% to 70% by weight, preferably 50% to 60% by weight, of protein by dry matter, based on the total dry weight of the oat protein composition.

[0020] In the present application, a "protein isolate" is to be understood as an oat protein composition which contains more than 70% by weight, preferably more than 80% by weight, of protein by dry matter, based on the total dry weight of the oat protein composition.

[0021] To determine the protein content, various protocols in the prior art can be used. In the present application, the preferred method for determining the protein content consists of 1) analyzing the nitrogen content in the composition using the Kjeldahl method, and 2) multiplying the nitrogen content by a factor of 6.25, which represents the average amount of nitrogen in the protein.

[0022] In this application, a "protein" is to be understood as a molecule consisting of one or more long chains of amino acid residues. In this application, a protein may be a native protein or a denatured protein, including hydrolyzed protein. These proteins may be present in various concentrations, including protein isolates or protein concentrates. Oats are the only cereal grain that contains avenin as a globulin or legume-like protein as the major storage protein (80% by weight). Globulins are characterized by their solubility in dilute saline, in contrast to more common cereal proteins such as gluten and zein, which are prolamines. A minor protein in oats is a prolamine called avenin.

[0023] In the present application, "lipids" should be understood as molecules that are 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 have the second highest lipid content of all cereals after corn, for example, more than 10% by weight in some oats and as much as 17% by weight in some corn cultivars, compared to about 2-3% by weight in wheat and most other cereals. The polar lipid content of oats (about 8-17% by weight glycolipids and 10-20% by weight phospholipids or about 33% by weight total polar lipid content) is greater than that of other cereals, since the majority of the lipid fraction is contained in the endosperm.

[0024] To quantify residual lipids, all methods known to those skilled in the art can be used.Preferably, Test A based on CEM method is used.CEM method is based on NMR analysis and gives extractable lipid content.In Test A based on CEM method, sample is simply put into the device, and analysis is started according to user manual, and result is obtained very quickly.

[0025] 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.

[0026] The oat protein composition comprises 0.1-10% by weight of starch on dry matter, preferably 0.5-6%, more preferably 1-4%, based on the total dry weight of the oat protein composition. The starch content of the composition can be determined using AOAC Official Method 996.11, Starch (Total) in Cereal Products.

[0027] The oat protein composition comprises 0.1-10% fiber by weight on dry matter, preferably 0.5-6%, more preferably 1-4% total dietary fiber, based on the total dry weight of the oat protein composition. In this application, the fiber content may be determined using AOAC Official Method 2017.16, Total Dietary Fiber in Foods and Food Ingredients. One type of dietary fiber commonly present in the composition is β-glucan.

[0028] The oat protein composition comprises less than 50%, advantageously less than 30%, preferably less than 10%, of proteins having a molecular weight of 10 kDa or less, based on the total weight of protein in the composition. In one embodiment, the oat protein composition comprises less than 50%, advantageously less than 30%, preferably less than 10%, of proteins having a molecular weight of 10 kDa or less, based on the total weight of protein in the composition. 0.5 to 30%, preferably 5 to 15%, of proteins having a molecular weight of 300 kDa or more; 30 to 75%, preferably 45 to 65%, of proteins having a molecular weight of 50 to 300 kDa; 10 to 50%, preferably 25 to 45%, of a protein having a molecular weight of 10 to 50 kDa; Contains 0.5 to 20%, preferably 1 to 10%, of a protein having a molecular weight of 10 kDa or less; Here the total is 100%.

[0029] An advantage of this preferred embodiment of the invention is that the oat protein composition has a high molecular weight, which can provide different protein functions compared to low molecular weight oat protein compositions, e.g. as described in the Bruckner-Guhmann et al. document.

[0030] The molecular weight (MW) distribution of proteins can be determined using size exclusion chromatography. Protocols for preparation of samples for analysis and measurement using size exclusion chromatography are included in the Examples section below.

[0031] In this application, "particle size" should be understood as a concept introduced to compare the dimensions of solid, liquid, or gaseous particles. The particle size distribution (PSD) of a powder, or a granular material, or particles dispersed in a fluid is a list of values ​​or a mathematical function that defines the relative amount of particles present according to size, generally by mass. Several methods can be used to measure the size and size distribution of particles. Some of them are based on light, or ultrasound, or electric fields, or gravity, or centrifugation. The use of sieves is a common measurement technique. In this application, the use of laser diffraction methods is preferred. For the "mean particle size" (d50) determined by laser diffraction, this mean particle size is the volume-weighted mean particle size. The skilled person can select a laser diffraction method that allows accurate measurements of the mean particle size to be obtained. Examples of such methods are given in the Examples section.

[0032] In this application, "dry matter" is to be understood as the relative weight percentage of solids based on the total weight of the sample. All known methods can be used, but the drying method, which consists in estimating the amount of water by heating a known amount of sample, is preferred. In the drying method: Prepare a sample and weigh its mass: m1 (g); The sample is placed in an oven to evaporate the water until the mass of the sample stabilizes. Preferably, the temperature during this step is 105° C. at normal atmospheric pressure. The final sample was weighed: m2 (g), Calculate the dry matter according to the following formula: dry matter = (m2 / m1)*100.

[0033] A second embodiment of the present invention is a process for producing an oat protein composition having a residual lipid content of less than 10% by weight on dry matter, based on the total dry weight of the oat protein composition, which is an oat protein composition as defined above, comprising the following steps: 1) providing oat seeds or providing protein-rich oat flour; 2) if oat seeds are used in step 1, grinding the oat seeds of step 1 until a 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 an amylase enzyme to the protein-rich suspension of step 3 to hydrolyze the protein-rich suspension; 5) Optionally, separating the hydrolyzed protein-rich suspension of step 4 by centrifugation until a heavy layer containing fiber and a light layer containing protein are obtained; 6) adding polysorbate to the hydrolyzed protein-rich suspension of step 4 or, optionally, to the protein-containing light phase of step 5; 7) centrifuging the polysorbate-containing protein-rich suspension or the protein-containing light layer of step 6 to separate it into a protein-containing heavy layer and a lipid-containing light layer containing soluble compounds; and 8) Optionally, the method further comprises a step of drying the heavy layer containing the protein of step 7.

[0034] Thus, the process of the present invention does not use organic solvents and can result in compositions that do not contain traces of organic solvents.

[0035] The first step is aimed at providing oat seeds in a state ready for further processing. The oat seeds may be cultivated and / or commercially available. The oat seeds are then prepared, possibly including sieving or hulling.

[0036] The oat seeds may be dry or wet heated before use. The purpose of dry or wet heating is to destroy enzymes including β-glucanase, lipase, and lipoxygenase. In fact, it has been shown that inactivation of lipase and lipoxygenase prevents spoilage of the product. In the process of the present invention, heat treatment, especially steam treatment, should be avoided or at least performed for at least the shortest possible time and / or at the lowest possible temperature so as to reduce denaturation of oat proteins.

[0037] The preferred raw materials used in the present invention for the preparation of the oat seeds in step 1 are Avena nuda, naked oats or hullless oats, or dry-milled oat flour that is not heat-treated, in particular not steam-treated. However, it is also possible to use wet-milled oat flour that is not heat-treated, or dry-milled flour of any oat fraction. Particularly preferred raw materials are dry-milled oats that are not heat-treated, oat bran that is not heat-treated, or oats that are not steam-treated.

[0038] The second step is aimed at grinding the oat seeds to obtain a protein-rich flour. All known common techniques can be used to grind the oat seeds, including stone mills, roller mills or knife mills. In this step, the preferred particle size distribution of the protein-rich flour obtained is a D50 (50th percentile) of more than 30 microns, preferably more than 40 microns, even more preferably more than 50 microns. In the present invention, D50 is measured using any technique known to the skilled person. In a preferred method, laser particle size analysis is preferred.

[0039] Protein rich flour comprises a protein content of more than 14%, such as more than 16%, based on the dry solids content of the protein flour.

[0040] Preferably, the content of insoluble fiber in the protein rich flour is less than 4%, preferably less than 2%, based on the dry solids content of the protein flour. These preferred ranges result in a low viscosity during processing, which makes the process easier to induce.

[0041] Instead of steps 1 and 2, it is possible to use directly commercially available oat flour. This alternative embodiment allows steps 1 and 2 as claimed in claim 1 to be combined, which are carried out by a third party, and allows a quick start with step 3.

[0042] The third step aims to obtain a protein-rich suspension, which is an oat flour suspension. As water, all food-compatible waters can be used, but tap water and decarbonated water are preferred. The aim of this third step is to obtain a dry matter content of 5% to 20%, preferably 10% to 15%, most preferably 10% to 13% by weight, based on the total weight of the suspension. Preferably, in step 3, flour is weighed into a tank with water and equipped with stirring, pH and heating devices. Preferably, during step 3, the temperature is adjusted to 60°C to 80°C, preferably 65°C to 75°C. Preferably, during step 3, the pH is adjusted to 5 to 6, preferably 5.5. In the present application, the pH can be adjusted by adding known acid or basic compounds, such as hydrochloric acid, sodium hydroxide, citric acid, calcium hydroxide and potassium hydroxide. The stirring is set to obtain a homogeneous suspension without foaming.

[0043] The fourth step aims at hydrolyzing the starch contained in the protein-rich suspension with amylase. Amylase is a type of enzyme that catalyzes the hydrolysis of starch molecules into smaller sugar molecules. In step 4 of the present application, all types of amylases can be used, such as β-amylase or amyloglucosidase, but α-amylase is preferred. In a preferred embodiment, thermostable α-amylase is preferred.

[0044] 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 dextrins or glucose syrup instead of starch. By converting this starch to a soluble form, the insoluble compounds can be more easily separated in the subsequent steps. However, as exemplified below, such separations known from the prior art are not effective for obtaining a protein composition with less than 10% by weight of lipids, based on the total dry weight of the protein composition.

[0045] In a preferred embodiment, the α-amylase enzyme is preferred. The activity of α-amylase is expressed in KNU units. In practice, α-amylase activity is measured using ethylidene-G7-PNP (4,6-ethylidene (G7)-p-nitrophenyl (G1)-α,D-maltoheptaoside) as a substrate. The compound is hydrolyzed by LE399 α-amylase to G2-PNP and G3-PNP, where G stands for glucose and PNP stands for p-nitrophenol. G2-PNP and G3-PNP are subsequently hydrolyzed to glucose and p-phenol by α-glucosidase added to the reaction mixture. The absorbance is measured spectrophotometrically at 409 nm under standard reaction conditions. 1 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 quantification limit of the method is about 0.3 KNU(T) / g. In step 4, the amylase added in step 4 has an activity level in the range of 100-170 KNU / 100 g flour, preferably 110-160 KNU / 100 g flour, even more preferably 120-150 KNU / 100 g flour. In other words, the unit amount of α-amylase introduced to hydrolyze starch is in the range of 100-170 KNU / 100 g flour, preferably 110-160 KNU / 100 g flour, even more preferably 120-150 KNU / 100 g flour. One Kilonovo α-amylase Unit (KNU) is a value known by those skilled in the art and is the amount of enzyme that will degrade a determined amount of starch per hour using the Novozymes standard method. The test consists of determining the α-amylase activity by comparison with an α-amylase standard (Termamyl) of known activity and is expressed in Kilonovo α-amylase Units (KNU). One KNU is the amount of α-amylase that will dextrinize 5.26 g of starch dry matter per hour under standard conditions (pH 7.1, 37° C.).

[0046] The fifth step consists of an optional centrifugation to separate the heavy layer containing the fibres from the light layer containing the proteins. In fact, as fibres and starch are insoluble and heavier than proteins, sugars and salts, they are separated by a centrifuge preferably operating at 3000G to 4000G.

[0047] As exemplified below, more than 70% of the dry matter obtained after step 5 consists of protein, preferably more than 80% of the dry matter.

[0048] The sixth step consists of adding polysorbate.

[0049] Polysorbates are a class of emulsifiers used in cosmetic, pharmaceutical and food preparations. Polysorbates are oily liquids derived from ethoxylated sorbitan (a derivative of sorbitol) esterified with fatty acids. Common brand names of polysorbates 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-(CH2CHO)- groups found in the molecule, and the number after "polysorbate" relates to the type of fatty acid attached to the polyoxyethylene sorbitan portion of the molecule). Preferably, the polysorbate is polysorbate 80 (polyoxyethylene (20) sorbitan monooleate), also known as Tween 80.

[0050] After hydrolysis in step 4 and optional removal of internal fiber in step 5, the pH may be adjusted to 5.5-7.5, preferably 6.5, before adding polysorbate in step 6. In step 6, polysorbate may be added at a temperature in the range of 50°C-80°C, preferably 55°C-75°C, and even more preferably 65°C.

[0051] Polysorbates may be added in a proportion ranging from 0.5% to 5% by weight, preferably from 2% to 4% by weight, more preferably 3% by weight, relative to the total weight of the protein-rich flour being oat flour.

[0052] Polysorbate 80 is preferred, and a commercially available example of polysorbate 80 is Tween 80 manufactured by Croda.

[0053] The medium may then be agitated under stirring, preferably for typically 1 hour.

[0054] The seventh step consists of centrifugation, which allows the protein-rich suspension to be separated into a heavy layer containing mainly proteins and a light layer containing other compounds, including lipids.

[0055] In a preferred embodiment, during step 7, the pH is first adjusted to 4-6, preferably 6. By adjusting the pH to this range, the protein coagulates. In a preferred embodiment, heat may be applied to aid coagulation. In this case, the temperature is set to 40°C-70°C, preferably 50°C-60°C. In all embodiments, the duration of step 7 is selected to obtain sufficient coagulation. Preferably, the duration of step 7 is set to 30 minutes-2 hours, preferably 45 minutes-1 hour. The medium is then fed into a centrifuge operating at 3000G-4000G. The pellet, the lower or heavy layer, containing the protein, is collected. The supernatant, the upper or light layer, containing the hydrolyzed starch and lipids, is discarded.

[0056] In a preferred embodiment, the pellet, bottom or heavy layer is mixed with water, agitated and then fed into a second centrifuge operating at 3000G to 4000G. Again, the pellet, bottom or heavy layer, containing the protein, is collected. The supernatant, top or light layer, containing the hydrolyzed starch and lipids, is discarded.

[0057] In a final, eighth, optional step, the oat protein concentrated in the pellet, bottom or heavy layer may be dried. To do so, the skilled person can preferably use a spray dryer, preferably a multi-stage spray dryer. This allows to obtain an oat protein composition with an average particle size as defined above. Before the spray drying, homogenization and UHT treatment steps may be carried out.

[0058] A third and final embodiment of the present invention is the use of the protein composition of the present invention, or obtained by the process of the present invention, preferably in the food, feed, pharmaceutical and cosmetic fields.

[0059] Such oat protein compositions are particularly suitable for canned beverages, beverages and baked goods, where their low fat content can improve the taste experience when formulated, as the low fat content and the presence of oxygen do not alter their organoleptic qualities due to undesirable compounds.

[0060] The present invention will be better understood from the following illustrative examples. EXAMPLES

[0061] How to determine MW distribution:

[0062] Samples were dissolved in 200 mM phosphate buffer, pH=7.6, vortexed for 1 min initially and after 10 min, and stored overnight at 4° C. The next day the solutions were centrifuged at 7000 g for 10 min, the supernatants were measured for soluble protein content, and samples were diluted to 10 mg / mL in phosphate buffer.

[0063] The samples were chromatographed using two SEC columns (400 and 300 Agilent Advanced Bio SEC columns, MW range 5000-1,250,000) at 0.5 mL / min with pH=7.6 phosphate buffer as the mobile phase, and detection was at UV=280 nm.

[0064] Several protein molecular weight standards (lysozyme, carbonic anhydrase, BSA, HSA, B-amylase, apoferritin, thyroglobulin) ranging from 14,300 to 669,000 Da were analyzed to determine retention times and calibrate the chromatographic instrument.

[0065] For the analysis of samples, the peak or peak apex(s) of the chromatogram was measured along with the range (start and end) of the peak and the molecular weight was determined for the range and peak apex. The percent molecular weight was determined as >300 kDa, 300 kDa-50 kDa, 50 kDa-10 kDa, and <10 kDa.

[0066] Example 1: Prior art processes involving starch hydrolysis

[0067] Weigh out 2.5 kg N°70 oat flour from Grien MIller, lot number 1802150. Fill the feed tank with 25 L water at 40-50°C. Mix the flour into the water. Adjust the pH to 5.4-5.5 with 1N HCl while stirring for 10 minutes. Add 25 g Liquozyme supra from Novozyme. Heat on a hot plate at 70°C for 2 hours at 300 rpm. Reduce the pH to 5.0 with 1N HCl and stir for 30 minutes. Feed at 500 mL / min to the Lemitec centrifuge at 580 G and 10 rpm differential. Add 12.5 L water at 50°C to the coagulum. Adjust the pH to 5.0 with 1N HCl. Feed at 500 mL / min to the Lemitec at 3600 rpm and 10 rpm differential. The washed coagulum is dried in a spray dryer.

[0068] The sample is referred to as "S1: Prior art without polysorbate."

[0069] Example 2: Process of the invention involving starch hydrolysis and use of polysorbate

[0070] Weigh out 2.5 kg N°70 oat flour from Grien MIller, lot number 1802150. Fill the feed tank with 25 L water at 40-50°C. Mix the flour into the water. Adjust the pH to 5.4-5.5 with 1N HCl while stirring for 10 minutes. Add 25 g Liquozyme supra from Novozyme. Heat on a hot plate at 70°C for 2 hours at 300 rpm. Add 75 g Tween 80. Adjust the pH to 6.5, cool to 65°C and hold for 60 minutes. Reduce the pH to 5.0 with 1N HCl and stir for 30 minutes. Feed into a Lemitec centrifuge at 500 mL / min, 580 G, 10 rpm differential speed. Add 12.5 L water at 50°C to the coagulum. Adjust the pH to 5.0 with 1N HCl. Feed the Lemitec at 500 mL / min with 3600 rpm and a differential speed of 10 rpm. Dry the washed coagulum in a spray dryer.

[0071] The sample is called "S2: Inventive method with polysorbate".

[0072] Example 3: The importance of the choice of polysorbate as a surfactant

[0073] Polysorbate is compared to another known food grade surfactant, sodium dodecyl sulfate.

[0074] Weigh out 2.5 kg N°70 oat flour from Grien MIller, lot number 1802150. Fill the feed tank with 25 L water at 40-50°C. Mix the flour into the water. Adjust the pH to 5.4-5.5 with 1N HCl while stirring for 10 minutes. Add 25 g Liquozyme supra from Novozyme. Heat on a hot plate at 70°C for 2 hours at 300 rpm. Add 75 g SDS. Adjust the pH of the SDS sample to 6, cool to 65°C and hold for 60 minutes. Reduce the pH to 5.0 with 1N HCl and stir for 30 minutes. Feed into a Lemitec centrifuge at 500 mL / min, 580 G, 10 rpm differential speed. Add 12.5 L water at 50°C to the coagulum. Adjust the pH to 5.0 with 1N HCl. Feed the Lemitec at 500 mL / min with 3600 rpm and a differential speed of 10 rpm. Dry the washed coagulum in a spray dryer.

[0075] The sample is referred to as "S3: Comparative Example with SDS."

[0076] Example 4: Importance of parameters of reaction with polysorbates

[0077] Weigh out 2.5 kg N°70 oat flour from Grien MIller, lot number 1802150. Fill the feed tank with 25 L water at 40-50°C. Mix the flour into the water. Adjust the pH to 5.4-5.5 with 1N HCl while stirring for 10 minutes. Add 25 g Liquozyme supra (Novozyme). Heat on a hot plate at 70°C for 2 hours at 300 rpm. Add 75 g Tween 80. Adjust the pH to 6.5, cool to 35°C and hold for 60 minutes. Reduce the pH to 5.0 with 1N HCl and stir for 30 minutes. Feed into a Lemitec centrifuge at 500 mL / min, 580 G, 10 rpm differential speed. Add 12.5 L water at 50°C to the coagulum. Adjust the pH to 5.0 with 1N HCl. Feed the Lemitec at 500 mL / min with 3600 rpm and a differential speed of 10 rpm. Dry the washed coagulum in a spray dryer.

[0078] The sample is referred to as "S4: Polysorbate treatment under non-optimal conditions."

[0079] Example 5: Preferred embodiment using centrifugation of fibers prior to the use of polysorbate

[0080] Weigh out 2.5 kg N°70 oat flour from Grien MIller, lot no. 1802150. Fill the feed tank with 25 L water at 40-50°C. Mix the flour into the water. Adjust the pH to 5.4-5.5 with 1N HCl while stirring for 10 minutes. Add 25 g 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 in a Lemitec centrifuge with a 60 / 10 weir at 500 ml / min, 580G, 10 rpm differential. Add 75 g Tween 80 to the overflow. Adjust the pH to 6, cool to 65°C and hold for 60 minutes. Reduce the pH to 5.0 with 1N HCl. Feed to Lemitec centrifuge at 580G, 3600 rpm, differential speed of 10 rpm. Add 12.5 L water at 50° C. to the coagulum. Adjust pH to 5.0 with 1 N HCl. Feed to Lemitec at 500 mL / min, 3600 rpm, differential speed of 10 rpm. Dry the washed coagulum in a spray dryer.

[0081] The sample is called "S5: Fiber centrifugation used prior to use of polysorbate."

[0082] Example 6: Comparison of previous examples

[0083] The results are shown below in Table 1, where the percentages are expressed as weight percent using the method described above. D50 was measured by a laser particle sizer (Malvern's Mastersizer3000) using forward scattering measurements to measure the intensity of scattered light over a range of scattering angles on dry powders without dispersion buffer, and using the instrument's software to fit the Mie scattering model to the measured scattering pattern.

[0084] [Table 1]

[0085] Example 7: Pilot scale production of oat protein compositions

[0086] The protein composition was prepared using the following protocol.

[0087] Weigh out 12.5 kg of oat flour (Grain miller no. 70) and fill a 50 gallon jacketed tank with approximately 88 L of 50°C water and mix the flour into the water to give 12% solids. Adjust the pH to 5.4-5.5 with HCl while stirring for 10 minutes and add 125 g of Liquozyme supra (Novozyme). Heat to 70°C in a heat exchanger using a recirculation pump for 2 hours. Then adjust the pH to 7.0 with NaOH and feed at 2000 ml / min to a Lemitec decanter centrifuge with a 60 / 10 weir at 5000 rpm with a 10 rpm differential and collect the overflow in a 50 gallon tank. Add 210 g of a 30% solution of Tween 80 (62.5 g of pure T80) to the tank and heat to 65°C and hold for 60 minutes. The tank is filled to the brim with water, heated to 60°C, and the pH is lowered to 5.0 with HCl. 3 / h, centrifuge in a Clara 20 disk centrifuge at 9,000 rpm. Resuspend the underflow fraction in a 50 gallon jacketed tank, top off with water and heat to 60°C, repeat the centrifugation process, and store the underflow fraction in a 5 gallon bucket in the refrigerator overnight. Heat to 40°C, adjust pH to 7.0, and pass through an ultra-high temperature unit (154°C hold temperature, 71°C flash temperature, 15 second hold time (380 ml / min, 200 pp rate, long loop)). Dry in a spray dryer.

[0088] The oat protein composition contains 82.8% protein, 6.1% lipid, 1.5% insoluble fiber, 1.6% soluble fiber, 1.7% beta-glucan, and 3.3% moisture. The starch content is determined to be about 2-3%. The MW distribution is shown in Table 2 below.

[0089] [Table 2]

Claims

1. 1. An oat protein composition characterised in that it does not contain any traces of organic solvents, has a residual lipid content of less than 10% by weight on dry matter, based on the total dry weight of the oat protein composition, and has an average particle size (d50) of more than 10 microns as determined by laser diffraction, The composition comprises, based on the total weight of protein in the composition, Proteins with a molecular weight of 300 kDa or more: 5-15% Proteins with molecular weights of 50-300 kDa: 45-65% 25-45% of proteins with molecular weights between 10 and 50 kDa; Contains 1-10% of proteins having a molecular weight of 10 kDa or less; An oat protein composition wherein the sum is 100%.

2. 2. The oat protein composition of claim 1, wherein the composition contains from 40% to 70% protein by weight on dry matter, based on the total dry weight of the oat protein composition.

3. 10. The oat protein composition of claim 1, wherein the composition contains more than 70% protein on a dry matter basis, based on the total dry weight of the oat protein composition.

4. The oat protein composition according to any one of claims 1 to 3, wherein the composition comprises 0.1 to 10% by weight of dry matter of starch, based on the total dry weight of the oat protein composition.

5. 5. The oat protein composition according to any one of claims 1 to 4, wherein the composition comprises 0.1 to 10% total dietary fibre by weight of fibre dry matter, based on the total dry weight of the oat protein composition.

6. The composition, an average particle size of greater than 20 microns; and 6. The oat protein composition according to any one of claims 1 to 5, which is present in an average particle size of less than 300 microns.

7. A process for producing an oat protein composition having a residual lipid content of less than 10% by weight on dry matter, based on the total dry weight of the oat protein composition, comprising the steps of: 1) providing oat seeds or providing protein rich flour; 2) if oat seeds are used in step 1, grinding the oat seeds of step 1 until a 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 an amylase enzyme to the protein-rich suspension of step 3 to hydrolyze the protein-rich suspension; 5) Optionally, separating the hydrolyzed protein-rich suspension of step 4 by centrifugation until a heavy layer containing fiber and a light layer containing protein are obtained; 6) adding polysorbate to the hydrolyzed protein-rich suspension of step 4 or, optionally, to the protein-containing light phase of step 5; 7) centrifuging the protein-rich suspension containing polysorbate of step 6 or the light layer containing protein to separate it into a heavy layer containing protein and a light layer containing soluble compounds including lipids; and 8) Optionally, the process comprises drying the protein-containing heavy layer of step 7.

8. 8. The process of claim 7, wherein in step 6, the polysorbate is added at a temperature of from 50° C. to 80° C.

9. 9. The process of claim 7 or 8, wherein the amylase enzyme in step 4 is a thermostable amylase.

10. 10. The process according to any one of claims 7 to 9, wherein the amylase added in step 4 has an activity level in the range of 100-170 KNU / 100 g flour.

11. The process according to any one of claims 7 to 10, wherein the oat protein composition is as defined in any one of claims 1 to 6.

12. Use of a protein composition as defined in any one of claims 1 to 6 or obtainable according to the process according to any one of claims 7 to 11 in the food, feed, pharmaceutical and cosmetic fields.

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