Method for separating a cereal material into fractions that are respectively enriched with beta-glucan, proteins, lipids and starch

Abstract

The invention relates to a method for separating a cereal material, comprising the following steps: providing at least one cereal material (1); treating the cereal material by solid / liquid extraction (4) with an alcohol solution comprising at least 50% by volume of alcohol, so as to obtain a lipid-depleted solid fraction (6) and a lipid-enriched liquid fraction (5); grinding (7) the lipid-depleted solid fraction (6) and separating (9) the particles according to their size, so as to obtain a beta-glucan-enriched fraction (10) and a beta-glucan-depleted fraction (11); grinding (12) the beta-glucan-depleted fraction (11) and treating it by aeraulic separation (13), so as to obtain a protein-enriched fraction (14) and a starch-enriched fraction (15).

Description

[0001] Process for separating a cereal material into fractions respectively enriched in beta-glucan, proteins, lipids and starch

[0002] Field of invention

[0003] The present invention relates to processes for separating cereal material, in particular oats or barley, comprising deoiling by extraction using alcohol and dry fractionation. The invention also relates to the products (fractions) obtained by such processes.

[0004] Technical background

[0005] Beta-glucans are naturally occurring polysaccharides found in a variety of organisms, including plants (such as oats and barley), mushrooms (such as shiitake and reishi), and some algae and bacteria. They are molecules composed of glucose linked together by [3-glycosidic bonds.

[0006] Beta-glucans are known for their beneficial biological and functional properties. They are often considered soluble dietary fibers and have been studied for their potential immunomodulatory, antioxidant, cholesterol-lowering, and antitumor benefits. Beta-glucans are therefore used as functional ingredients in dietary supplements, health foods, and cosmetic products.

[0007] Oats and barley, as well as by-products from these grains and from malting, brewing, and plant-based dairies, are known to contain high levels of beta-glucan. Among the major cereals (wheat, rye, oats, and barley), oats and barley contain the highest amounts of beta-glucans. Oat and barley grains are made up of four main components:

[0008] - The glumes or beards (also called pellicles in this text): this is the fibrous bark that surrounds the whole grain. The operation of removing this part is called "trimming" or "dehulling". The grain freed from these glumes is called groats.

[0009] - The bran: this is the protective envelope (outer layer) of the seed. This part is very rich in fiber and beta-glucan

[0010] - The almond: this is the heart of the seed without its protective covering. The process of removing the covering from the grain is called hulling. The ground almond is known as flour.

[0011] - The endosperm: this is the main part of the almond. It contains carbohydrates in the form of starch and proteins.

[0012] - The germ: this is the smallest part of the almond. It contains most of the grain's fat.

[0013] Oat beta-glucans are found in the endosperm and its hull. Therefore, the whole grain must be hulled and fractionated to produce commercial bran enriched with beta-glucans. Using technology and certain processing conditions, natural oat bran with a high content of dietary fiber (such as up to 44%) and beta-glucans (up to 22%) can be obtained. In hulless barley, beta-glucans are more evenly distributed throughout the grain; therefore, even refined products, such as barley flour, contain beta-glucans.

[0014] Products and co-products from the use of oats and barley, particularly in malting, brewing, distilling, plant-based dairying and milling, are also rich in beta-glucans.

[0015] Diets that include soluble fiber from certain foods and are low in saturated fat and cholesterol may reduce the risk of coronary heart disease. Recent studies have identified beta-glucan as the physiologically active component responsible for the cholesterol-lowering effect observed with oat consumption. The health claim that regular consumption of beta-glucan can reduce cholesterol levels and the risk of coronary heart disease is currently approved by the U.S. Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA).

[0016] Beta-glucans are linear, unbranched, non-starch polysaccharides composed of glucose molecules linked by [3(1 — >4) and [3(1 — >3] bonds, and thus exhibit physical properties of water solubility and gelation. The ability of beta-glucans to form highly viscous solutions at relatively low concentrations in the human intestine is thought to represent a fundamental element of the health benefits of these substances.The cholesterol-lowering effect of soluble beta-glucan fiber is thought to be attributable to several mechanisms of action: increased excretion of bile acids and cholesterol, reduced insulin secretion (resulting in reduced cholesterol synthesis), production of short-chain fatty acids (which may inhibit cholesterol biosynthesis), reduced fat absorption rates, and inhibition of pancreatic lipase or reduced gastric lipase activity.

[0017] Beta-glucans in cereals have also been shown to reduce glycemic response, which could help improve metabolic regulation in diabetics.

[0018] Cereals, and in particular barley and oats (including products and co-products derived from the use of these two cereals), contain other constituents that also have interesting nutritional and functional characteristics, such as proteins, starch and oil (lipids). All these compounds find applications in food, pharmacy and cosmetics.

[0019] Furthermore, in Commission Implementing Regulation (EU) No 828 / 2014 of 30 July 2014, the European Union acknowledges that "most people who suffer from gluten intolerance can include oats in their diet without adverse effects on their health. The scientific community is conducting ongoing studies and research on this issue." Oat proteins are therefore likely to be an interesting alternative to wheat proteins traditionally used in food.

[0020] The use of various fractionation technologies to recover beta-glucans and proteins contained in cereal grains, particularly oats or barley, as well as in the products and co-products derived from the use of these two cereals, is unfortunately almost impossible due to a high fat content in the grains and the products derived from their use. Thus, the average lipid content in oat groats varies between 4 and 8% of the dry matter weight, causing sticking to the walls of the mill in the case of direct grinding of the grain or groats.

[0021] In order to fractionate oat or barley grain or the products and co-products derived from their use, a preliminary deoiling step is necessary. The historical process is hexane extraction. For example, the article by Wu et al., "Enriched Protein- and -Glucan Fractions from High-Protein Oats by Air Classification", Cereal Chemistry, 1995, vol. 72, no. 1, pp. 132-134, describes a process for obtaining protein- and beta-glucan-enriched fractions from oats, in which the oats are first dehulled in a pin mill, the recovered groats are then defatted using hexane, and the defatted groats are then ground and subjected to air separation.

[0022] However, the use of this solvent has several major drawbacks. First, it is produced from petroleum, resulting in high greenhouse gas emissions (e.g., 620 kg CCheq / t). In addition, its degree of toxicity is high, and after extraction, hexane residues are still present in the grain subjected to treatment.

[0023] More recently, hexane has been replaced by supercritical CO2 as an extraction solvent. The main advantage of using this solvent is that it does not leave toxic residues in the powder, but this new technology remains very energy-intensive and expensive, and requires significant investment.

[0024] For example, WO 2008 / 096044 describes a process for producing beta-glucan, protein, starch and lipid concentrates from oats, comprising a step of extracting the oats using a supercritical fluid, a step of dry milling the delipidated fraction, a step of separating the fraction obtained into a starch-enriched fraction and a beta-glucan-enriched fraction and a step of separating by sieving or by aeraulic separation the starch-enriched fraction to obtain 3 fractions: a fraction comprising a protein concentrate, one comprising a beta-glucan concentrate and a fraction comprising a starch concentrate.

[0025] The article by Sibakov et al., "Lipid Removal Enhances Separation Of Oat Grain Cell Wall Material From Starch And Protein", Journal of Cereal Science, 2011, vol. 54, no. 1, pp. 104-109, describes a process comprising milling of oat groats, extraction of lipids using supercritical CO2, followed by milling and then a first step of aeraulic separation of the defatted oats. The resulting larger particle fraction is subjected to milling and a second step of aeraulic separation to obtain a fraction enriched in beta-glucans. The finer particle fraction obtained from the first step of aeraulic separation is also subjected to another step of aeraulic separation to obtain a fraction enriched in protein and a fraction enriched in starch.Additionally, current cereal beta-glucan extraction processes can lead to certain negative effects that can alter their properties and functionality. For example, they can alter their native structure, which can reduce their ability to form a viscous gel in the intestinal tract. This loss of structure can lead to a decrease in their beneficial effects, such as cholesterol reduction and blood sugar regulation.

[0026] There is therefore a real need to develop a process for obtaining fractions enriched, respectively, in oil (or lipids), starch, protein and beta-glucan from cereals, leading to low denaturation of the components to be isolated and in particular beta-glucans and proteins, and having a lower greenhouse gas emission.

[0027] Summary of the invention

[0028] The invention relates firstly to a method for separating a cereal material, comprising the following steps:

[0029] - the supply of at least one cereal material comprising starch, proteins, lipids and beta-glucans;

[0030] - the treatment of cereal material by solid / liquid extraction with an alcohol solution comprising at least 50% by volume of alcohol, so as to obtain a solid fraction depleted in lipids and a liquid fraction enriched in lipids;

[0031] - grinding of the solid fraction depleted in lipids;

[0032] - separation of the particles of the crushed lipid-depleted fraction according to their size, so as to obtain a fraction enriched in beta-glucans and a fraction depleted in beta-glucans;

[0033] - grinding of the fraction depleted in beta-glucans; and

[0034] - the treatment of the fraction depleted in crushed beta-glucans by aeraulic separation, so as to obtain a fraction enriched in proteins and a fraction enriched in starch.

[0035] In embodiments, the cereal material is an oat and / or barley cereal material.

[0036] In embodiments, the cereal material is at least one cereal grain and / or at least one product from the malting, malt extract manufacturing, brewing, cereal distillation, plant-based dairy and / or milling industries.

[0037] In embodiments, the alcohol solution is a mixture of alcohol and at least one solvent, the solvent preferably being selected from the group of water, 2-methyloxolane and mixtures thereof, more preferably the alcohol solution consists of a mixture of alcohol and water.

[0038] In embodiments, the alcohol solution comprises from 50 to 90% by volume alcohol.

[0039] In embodiments, the alcohol of the alcohol solution is recycled alcohol.

[0040] In embodiments, the alcohol of the alcohol solution is ethanol.

[0041] In embodiments, milling the beta-glucan depleted fraction comprises micronizing the beta-glucan depleted fraction.

[0042] In embodiments, separation of particles from the milled lipid-depleted fraction according to their size is carried out by sieving.

[0043] In embodiments, the method further comprises a step of separating the alcohol from the lipid-enriched liquid fraction, preferably by distillation, the method preferably further comprising a step of recycling the separated alcohol to the solid / liquid extraction step.

[0044] In embodiments, the method further comprises, before the step of treating the cereal material by solid / liquid extraction, a step of grinding and / or flattening the cereal material, so as to obtain a ground and / or flattened fraction, the cereal material provided preferably being a cereal grain.

[0045] In embodiments, the cereal material is a cereal grain comprising a skin, the method further comprising a step of dehulling the grain prior to the step of grinding and / or flattening the cereal material.

[0046] In embodiments, the beta-glucan-enriched fraction comprises an amount of beta-glucan greater than or equal to 10% by weight, preferably 10 to 40% by weight, more preferably 15 to 25% by weight, relative to the total weight of dry matter of the fraction.

[0047] In embodiments, the starch-enriched fraction comprises an amount of carbohydrates greater than or equal to 40% by weight, preferably 40 to 90% by weight, more preferably 50 to 85% by weight, relative to the total weight of dry matter of the fraction.

[0048] In embodiments, the protein-enriched fraction comprises an amount of protein greater than or equal to 15% by weight, preferably 15 to 35% by weight, more preferably 15 to 30% by weight, more preferably 20 to 30% by weight, relative to the total weight of dry matter of the fraction.

[0049] The present invention makes it possible to meet the need expressed above. More particularly, it provides an improved process for separating a cereal material allowing the fractionation of four components of interest (oil, beta-glucans, starch, proteins) which is simple, efficient, more economical, which leads to low denaturation (transformation) of the fractionated components, in particular beta-glucans and proteins, which is environmentally friendly, with lower water consumption and reduced greenhouse gas emissions, and generating a minimum of effluents which are easy to recycle.

[0050] This is accomplished by combining an extraction deoiling step using a specific solvent, namely an alcohol solution comprising at least 50% by volume of alcohol, and a dry fractionation process using one or more grinding steps and an aeraulic separation step.

[0051] In particularly advantageous embodiments, in which the alcohol, and in particular ethanol, used for deoiling is recycled to be reused in the extraction step, the method according to the invention makes it possible to further reduce greenhouse gas emissions and thus the consumption of solvents and the generation of effluents.

[0052] Brief description of the figures

[0053] Figure 1 represents a flowchart of an example of a method according to the invention.

[0054] Detailed description

[0055] The invention is now described in more detail and in a non-limiting manner in the following description.

[0056] Unless otherwise stated, all percentages are by mass.

[0057] In this text, the quantities indicated for a given species may apply to this species according to all its definitions (as mentioned in this text), including the more restricted definitions.

[0058] In this text, by "fraction enriched in a substance X" obtained after a certain treatment, we mean a fraction in which the ratio of the molar proportions of substance X / total dry matter is higher than that of the fraction before treatment.

[0059] In this text, the terms “lipids”, “oil” and “fats” have the same meaning and are used interchangeably.

[0060] The invention relates to a method for separating a cereal material, in particular to obtain a lipid-enriched fraction, a beta-glucan-enriched fraction, a starch-enriched fraction and a protein-enriched fraction. In the context of the present invention, "cereal material" means any material based on, or derived from, at least one cereal, in any possible form (e.g., whole, ground, powdered, flattened, etc.). More particularly, it may be the cereal itself (raw), any part thereof, or any material obtained after treatment, processing or use of the cereal.

[0061] The process according to the invention involves a step of de-oiling the grains by extraction using an alcohol solution comprising at least 50% by volume of alcohol followed by dry fractionation of the cereal material. By "dry process" is meant any operation, such as grinding or air separation operations, which is carried out without the use of water.

[0062] Cereals are members of the Poaceae family. They produce grains, which include starch, protein, lipids, and soluble fiber, particularly beta-glucans. Cereal grains generally include at least one kernel surrounded by a hull. However, in this text, the term "grain" can generally refer to the entire (whole) grain as well as any part of the grain (e.g., the kernel without its glumes, or the kernel, etc.), unless otherwise specified.

[0063] Within the scope of the present invention, the starting cereal material may be, or originate from, any suitable cereal. However, particularly preferably, this cereal is selected from the group consisting of oats, barley and mixtures thereof.

[0064] In the present invention, any suitable cereal material, including starch, proteins, lipids and beta-glucans, may be used.

[0065] Thus, advantageously, the starting cereal material used in the invention may be a cereal grain (in particular an oat and / or barley grain). The dehulled oat grain (i.e., the grain from which the glumes have been removed) is called groats. The dehulled barley grain is called hulled barley. In the present text, the terms “oat grain” and “barley grain” mean both the total grain and any part of the grain (for example, oat groats or hulled barley), unless otherwise indicated. Oat and barley grains have the advantage of being rich in beta-glucan (they may comprise from 3 to 7% by weight for oats and from 3 to 11% by weight for barley). Preferably, a cereal grain, in particular an oat and / or barley grain, comprising a husk and a groat, is used as the starting raw material.

[0066] Alternatively or additionally, any product resulting from the use or processing of a cereal (in particular oats or barley) may advantageously be used as the starting cereal material, in particular in fermentation and distillation processes, for the production of sprouted cereal (in particular malt), for the production of vegetable beverages or for the production of flours. More particularly, products which can be used in the process according to the invention are:

[0067] - malting and malt extract manufacturing by-products: during the barley germination process, radicles (small roots) are formed. After drying, the grains are treated to remove the radicles and the grain husk. These two products are rich in proteins and beta-glucans.

[0068] - Brewery and / or cereal distillation co-products: after the fermentation stage, the “wort” is filtered to remove all solid residues from the cereal grain. This substrate is rich in proteins and beta-glucans.

[0069] - Plant-based dairy by-products: During the production of plant-based drinks, a filtration or decantation process is carried out to remove solid residues from the cereal grain. These residues are called okara. These residues contain a high level of proteins and beta-glucans.

[0070] - Milling products.

[0071] When the cereal material is a cereal grain, and more particularly an oat and / or barley grain, the method according to the invention advantageously comprises a step of removing the skin (or dehulling) from the cereal grains (in particular oats and / or barley). Indeed, the skin is composed mainly of insoluble fibers that are not very edible. In addition, the majority of contaminants in the oat or barley grain are found in the skin, its removal thus makes it possible to reduce the risks of contamination of the prepared fractions.

[0072] Preferably, the de-filming is a mechanical de-filming, carried out for example by abrasion, compression, impact, shearing or any other suitable mechanical action. More preferably, the de-filming is carried out by abrasion.

[0073] Hulling can be carried out using any suitable device, in particular using one of the mechanical forces mentioned above, in particular abrasion. Advantageously, the hulling is carried out using a de-huller. De-hullers operate according to the principle of a friction polishing machine. They can be used to remove beards, debind double grains and to treat the surface of cereal grains. In an example of a hulling process using a de-huller, a feed screw transports the cereals into the working chamber where a rotor in a perforated sleeve subjects the treated product to mechanical forces by friction. The intensity of the friction can be adjusted, for example by an adjustable counterweight, or by adjustable springs at the outlet of the machine.Loose elements that are separated from the processed product (the grain), such as burrs or impurities adhering to the surface, can exit the machine through a separate vacuum outlet.

[0074] Using a dehuller to perform hulling is advantageous because the dehuller cleans the grain surface at the same time as it detaches the skin from the grain by mechanical stress. In addition, this processing step helps improve the flow properties of the grains.

[0075] The cereal material may be subjected to a grinding and / or flattening step and a ground and / or flattened fraction is then collected. This step is in particular carried out when the starting cereal material is a cereal grain. When the method comprises a dehulling step as described above, the grinding and / or flattening step is preferably carried out after the dehulling (the cereal material subjected to this grinding and / or flattening step then being a dehulled grain). This grinding and / or flattening step may be omitted, in particular when the starting cereal material is in powdered or flattened form, for example in embodiments in which the starting cereal material is a product resulting from the use of a cereal.Conversely, when the cereal material is not in powdered or flattened form, the method according to the invention preferably comprises this step of grinding and / or flattening said cereal material. The grinding can be carried out using any type of grinder, in particular by any mechanical grinder using compression, impact, shear or any other appropriate mechanical action. Preferably, the particles obtained after grinding have a volume median diameter (D50) greater than or equal to 500 μm (the D50 can be measured according to standard NF ISO 13320-1). This grinding step can be carried out regardless of the cereal material (in particular, cereal grain and / or product resulting from the use of a cereal).

[0076] Flattening may be carried out using a grain flattener, preferably using mechanical compression force. This flattening step is preferably carried out when the grain material used is a cereal grain.

[0077] The cereal material (in embodiments, the ground and / or flattened fraction obtained after grinding and / or flattening) is subjected to a solid / liquid extraction carried out using an alcohol solution. The alcohol solution according to the invention comprises at least 50% by volume of alcohol. The alcohol solution may be the alcohol itself (it then comprises 100% by volume of alcohol). However, it is preferably a mixture comprising at least one alcohol and at least one solvent. The solvent is preferably selected from the group consisting of water, 2-methyloxolane and mixtures thereof. More preferably, the alcohol solution is an aqueous alcohol solution, i.e., a solution comprising water and alcohol. Even more preferably, the aqueous ethanol solution consists of water and alcohol.Advantageously, the alcohol solution comprises less than 10% by volume, preferably less than 5% by volume, more preferably less than 2% by volume, of supercritical CO2 and preferably supercritical fluid; more preferably the alcohol solution is free of supercritical CO2, more particularly free of supercritical fluid.

[0078] The alcohol solution preferably comprises from 50 to 90% by volume, more preferably from 60 to 90% by volume, more preferably from 70 to 90% by volume, even more preferably from 80 to 90% by volume, of alcohol (based on the total volume of the alcohol solution used to carry out the extraction). In embodiments, the alcohol solution comprises from 50 to 60%, or from 60 to 70%, or from 70 to 80%, or from 80 to 90%, by volume, of alcohol.

[0079] The alcohol is preferably selected from the group consisting of ethanol, methanol, pentanol, isoamyl alcohol and mixtures thereof. Most preferably, the alcohol is ethanol. In other words, the alcohol solution used according to the invention is preferably an ethanol solution.

[0080] The extraction is advantageously carried out by contacting the cereal material (for example the ground and / or flattened fraction) with the alcohol solution (preferably ethanol) in a reactor, preferably with stirring. Preferably, the cereal material (for example the ground and / or flattened fraction) is contacted with the alcohol solution (preferably ethanol) in a mass ratio of 1:3 to 1:8, more preferably in a mass ratio of 1:4 to 1:7 (for example in a mass ratio of 1:3 to 1:4, or 1:4 to 1:5, or 1:5 to 1:6, or 1:6 to 1:7, or 1:7 to 1:8). The contacting advantageously takes place for a period of 15 to 120 min, preferably 20 to 60 min. Preferably, the cereal material particles are then separated from the alcohol solution by filtration, for example through a 10 μm mesh screen.

[0081] Particularly advantageously, when the alcohol solution is an ethanol solution, the ethanol used in the ethanol solution is produced by fermentation from a substrate as described in patent application FR 2211884 filed on November 11, 2022 and entitled “Process for preparing a substrate for fermentation”.In particular, the fermentation substrate may be prepared by a method comprising the following steps: providing at least one legume seed comprising starch and proteins; micronizing said at least one seed, so as to obtain a micronized fraction; purifying the micronized fraction (preferably by aeraulic separation), so as to collect a starch-enriched and protein-depleted fraction; mixing the starch-enriched and protein-depleted fraction with a liquid, so as to form a starch fluid; hydrolyzing the starch by mixing steam with the starch fluid (preferably carried out using a direct steam injection device in continuous mode), so as to obtain a hydrolyzed starch fluid; and preferably introducing into the hydrolyzed starch fluid one or more glucosidase and / or saccharidase enzymes.The use of such a process to prepare the fermentation substrate for ethanol production has the advantage of having a relatively low greenhouse gas emission rate, which can be less than 400 kg of CO2. eq / t of ethanol

[0082] Preferably, the alcohol (preferably ethanol) used to prepare the alcohol solution is a recycled alcohol, i.e. it has already been previously used in a treatment process, preferably in an extraction process, more preferably in an extraction step of a process according to the invention.

[0083] The extraction step according to the invention makes it possible to extract at least a portion of the lipids from the cereal material in the alcohol solution (preferably ethanol). Thus, at the end of the extraction step, and preferably the filtration step, a liquid fraction enriched in lipids and a solid fraction depleted in lipids (also called cake) are obtained.

[0084] The cake is advantageously subjected to a drying step. Preferably, it is dried in a vacuum oven, preferably at a temperature of 30 to 50°C. Preferably, the cake is dried for a period of 2 to 10 hours.

[0085] The extraction step may be repeated one or more times on the cake, preferably after drying the cake. In other words, the process according to the invention may comprise one, two or more extraction steps using an alcohol solution (preferably ethanol).

[0086] The lipid-enriched liquid fraction (comprising the alcohol-fat mixture) is preferably subjected to a purification step in order to separate the alcohol (preferably ethanol) from the lipid-enriched fraction. More preferably, the alcohol (preferably ethanol) is separated by distillation. In particular, the lipid-enriched liquid fraction may be distilled at a temperature of 30 to 70°C, preferably in a tray column under vacuum. The oil is recovered at the bottom of the column (forming a purified lipid-enriched fraction) while the alcohol (preferably ethanol) is collected at the top of the column.

[0087] Particularly advantageously, the alcohol (preferably ethanol) recovered after separation of the lipid-enriched liquid fraction is recycled, and is more particularly reused for a new extraction cycle of the process according to the invention.

[0088] The method according to the invention comprises a step of grinding the lipid-depleted solid fraction (cake), preferably dried, then a step of separating the particles obtained according to their size. The purpose of these steps is to separate the beta-glucan fraction from the starch and protein fractions. For grinding, any suitable type of grinder can be used, in particular any grinder using mechanical force of abrasion, compression, impact, shear or any other mechanical action. In particular, a pendulum grinder using compression force can be used. At the end of the grinding, a mixture of fragments of the shell (essentially fibers) (also called bran in this text) and almond powder (also called flour in this text) is obtained.

[0089] The step of separating the particles obtained from the grinding is preferably carried out by sieving. In particular, the particles may be separated by passing them over a suitable mesh sieve for separating the bran from the flour. For example, particles smaller than 200 to 600 pm (for example smaller than 200 to 250 pm, or 250 to 300 pm, or 300 to 350 pm, or 350 to 400 pm, or 400 to 500 pm, or 500 to 600 pm) may be separated from bran larger than or equal to such a size. In particular, a sieve with a mesh size of between 200 and 600 pm can be used (for example, a sieve with a mesh size of between 200 and 250 pm, or between 250 and 300 pm, or between 300 and 350 pm, or between 350 and 400 pm, or between 400 and 500 pm, or between 500 and 600 pm).The bran separated during this step (i.e. particles of a size greater than or equal to the size previously mentioned, more particularly particles of a size greater than or equal to the mesh size of the sieve used, therefore particles retained by the sieve) correspond to a fraction enriched in beta-glucans; the flour obtained after separation (i.e. particles of a size less than the size previously mentioned, more particularly particles of a size less than the mesh size of the sieve used, therefore particles passing through the sieve) corresponds to a fraction depleted in beta-glucans.

[0090] Preferably, the beta-glucan-enriched fraction comprises a quantity of carbohydrates greater than or equal to 40% by weight, preferably an amount of 40 to 90% by weight, more preferably 40 to 80% by weight, more preferably 45 to 70% by weight (relative to the total weight of dry matter of the fraction). In particular, the quantity of carbohydrates in the beta-glucan-enriched fraction may comprise 40 to 50% by weight, or 50 to 60% by weight, or 60 to 65% by weight, or 65 to 70% by weight, or 70 to 75% by weight, or 75 to 80% by weight, or 80 to 90% by weight, relative to the total weight of dry matter of the fraction. The quantity of carbohydrates may be measured according to ISO 15914.

[0091] Preferably, the beta-glucan-enriched fraction comprises a protein amount of less than or equal to 30% by weight, preferably an amount of 0.5 to 30% by weight, more preferably 3 to 20% by weight, more preferably 5 to 15% by weight (relative to the total dry matter weight of the fraction). In embodiments, the protein amount in the beta-glucan-enriched fraction may be, relative to the total dry matter weight of the fraction, 0.5 to 3% by weight, or 3 to 5% by weight, or 5 to 7% by weight, or 7 to 10% by weight, or 10 to 12% by weight, or 12 to 15% by weight, or 15 to 20% by weight, or 20 to 30% by weight, relative to the total dry matter weight of the fraction. The amount of protein can be measured according to ISO 5983-2 (Kjeldahl method).

[0092] Preferably, the fraction enriched in beta-glucans comprises an amount of beta-glucan greater than or equal to 10% by weight, preferably an amount of 10 to 40% by weight, more preferably 15 to 25% by weight, relative to the total weight of dry matter of the fraction; in particular the fraction may comprise an amount of beta-glucan of 10 to 13% by weight, or 13 to 15% by weight, or 15 to 17% by weight, or 17 to 20% by weight, or 20 to 22% by weight, or 22 to 25% by weight, or 25 to 30% by weight, or 30 to 35% by weight, or 35 to 40% by weight relative to the total weight of dry matter of the fraction. The amount of beta-glucan can be measured according to the AOAC 995.16 method.

[0093] Preferably, the beta-glucan-enriched fraction comprises a quantity of fat (lipids) less than or equal to 5% by weight, preferably a quantity of 0.5 to 5% by weight, more preferably 0.5 to 3% by weight, relative to the total weight of dry matter of the fraction; in particular the fraction may comprise a quantity of fat of 0.5 to 1% by weight, or 1 to 2% by weight, or 2 to 3% by weight, or 3 to 4% by weight, or 4 to 5% by weight, relative to the total weight of dry matter of the fraction. The quantity of fat may be measured according to the AOAC 922.06 method.

[0094] The fraction depleted in beta-glucans (flour), obtained after separation of the fraction enriched in beta-glucan, is subjected to a grinding step, a ground fraction then being collected.

[0095] Particularly advantageously, this grinding comprises, or is, micronization, preferably by dry means. The ground fraction obtained is then a micronized fraction.

[0096] The micronization step separates the proteins from the starch granules to allow their subsequent separation.

[0097] By "micronization" is meant a grinding process that produces particles with a volume median diameter of less than 100 pm, preferably less than 50 pm, and even more preferably less than 30 pm. The volume median diameter (D50) of the particles can be measured according to standard NF ISO 13320-1. Micronization can be carried out by any suitable grinder (in particular, any grinder using mechanical forces of abrasion, compression, impact or shear). For example, a grinder using impact force can be used.

[0098] Micronization is most preferably carried out at room temperature (between 15 and 30°C).

[0099] Micronization has the additional advantage of being low in greenhouse gas emissions, as it is preferably carried out at room temperature and by dry means.

[0100] The method according to the invention comprises a step of separating the starch granules from the proteins of the fraction depleted in ground beta-glucans, preferably micronized.

[0101] At the end of the separation, a starch-enriched fraction, preferably a starch-enriched and protein-depleted fraction, is collected. A protein-enriched fraction, preferably a protein-enriched and starch-depleted fraction, is also recovered. By "starch-enriched and protein-depleted fraction" is meant a fraction in which the molar ratio of starch to protein (on dry matter) is higher than that of the fraction subjected to purification. By "protein-enriched and starch-depleted fraction" is meant a fraction in which the molar ratio of protein to starch (on dry matter) is higher than that of the fraction subjected to purification.

[0102] Given the difference in size between proteins and starch granules (D50 of approximately 1 to 5 pm for proteins and approximately 10 to 30 pm for starch granules) and in density, it is advantageous to use a separation based on a difference in size, density or weight of the particles. In the method according to the invention, the separation is an aeraulic separation. By "aeraulic separation" is meant any separation technology using a jet of gas (preferably air) entraining at least part of the particles to be separated. More preferably, the separation is a cyclonic separation. It can be carried out by means of a cyclone, advantageously associated with a selector. By "selector" is meant any variable-speed rotating element equipped with radial blades installed in a part (preferably the upper part) of a cyclonic separator.This equipment increases the efficiency of particle separation based on their density. The use of an aeraulic separation device allows the recovery of the lightest particles, carried by the gas flow, at one end of the device (protein-enriched fraction) while the heavier particles are collected at the other end (starch-enriched fraction). In other words, the aeraulic separation produces a fraction of lighter particles corresponding to the protein-enriched fraction and a fraction of heavier particles corresponding to the starch-enriched fraction.

[0103] The air separation is preferably carried out using a selector operating at a rotation speed between 7,000 and 14,000 rpm, more preferably between 8,000 and 13,000 rpm, more preferably between 9,000 and 12,000 rpm. The gas flow (preferably air) passing through the selector preferably has a flow rate between 40 and 200 m 3 / h, preferably still between 60 and 150 m 3 / h, more preferably between 80 and 120 m 3 / h.

[0104] Preferably, the starch-enriched fraction comprises an amount of carbohydrates greater than or equal to 40% by weight, preferably an amount of 40 to 90% by weight, more preferably 50 to 85% by weight, more preferably 60 to 82% by weight (relative to the total weight of dry matter of the fraction). In particular, the amount of carbohydrates in the recovered starch-enriched fraction may comprise 40 to 50% by weight, or 50 to 60% by weight, or 60 to 65% by weight, or 65 to 70% by weight, or 70 to 75% by weight, or 75 to 80% by weight, or 80 to 90% by weight, relative to the total weight of dry matter of the fraction.

[0105] Preferably, the starch-enriched fraction comprises an amount of protein of less than or equal to 15% by weight, preferably an amount of 0.5 to 15% by weight, more preferably 3 to 15% by weight, more preferably 8 to 15% by weight (relative to the total weight of dry matter of the fraction). In embodiments, the amount of protein in the recovered starch-enriched fraction may be, relative to the total weight of dry matter of the fraction, 0.5 to 3% by weight, or 3 to 5% by weight, or 5 to 7% by weight, or 7 to 10% by weight, or 10 to 12% by weight, or 12 to 15% by weight.

[0106] Preferably, the starch-enriched fraction comprises a quantity of fiber less than or equal to 10% by weight, preferably an amount of 0.5 to 10% by weight, more preferably 1 to 8% by weight, relative to the total weight of dry matter of the fraction; in particular the fraction may comprise a quantity of fiber of 0.5 to 2% by weight, or 2 to 4% by weight, or 4 to 6% by weight, or 6 to 8% by weight, or 8 to 10% by weight, relative to the total weight of dry matter of the fraction. The term "fiber" means all plant polymeric molecules, soluble or insoluble, other than starch and starch fragments. Fibers include in particular cellulose, hemicellulose, lignin, beta-glucans and pectin. The quantity of fiber can be measured according to the AOAC 2011.25 method.

[0107] Preferably, the collected starch-enriched fraction comprises a quantity of fat (lipids) less than or equal to 5% by weight, preferably a quantity of 0.5 to 5% by weight, more preferably 0.5 to 3% by weight, relative to the total weight of dry matter of the fraction; in particular the fraction may comprise a quantity of fat of 0.5 to 1% by weight, or 1 to 2% by weight, or 2 to 3% by weight, or 3 to 4% by weight, or 4 to 5% by weight, relative to the total weight of dry matter of the fraction.

[0108] Preferably, the protein-enriched fraction comprises an amount of protein greater than or equal to 15% by weight, preferably an amount of 15 to 35% by weight, more preferably 15 to 30% by weight, more preferably 20 to 30% by weight (relative to the total weight of dry matter of the fraction). In embodiments, the amount of protein in the recovered protein-enriched fraction may be, relative to the total weight of dry matter of the fraction, 15 to 18% by weight, or 18 to 22% by weight, or 22 to 25% by weight, or 25 to 28% by weight, or 28 to 32% by weight, or 32 to 35% by weight.

[0109] Preferably, the protein-enriched fraction comprises an amount of carbohydrates less than or equal to 75% by weight, preferably an amount of 0.5 to 70% by weight, more preferably 20 to 70% by weight, more preferably 40 to 70% by weight (relative to the total dry matter weight of the fraction). In embodiments, the amount of carbohydrates in the recovered protein-enriched fraction may be, relative to the total dry matter weight of the fraction, 0.5 to 20% by weight, or 20 to 30% by weight, 30 to 40% by weight, or 40 to 50% by weight, or 50 to 60% by weight, or 60 to 70% by weight, or 70 to 75% by weight.

[0110] Preferably, the protein-enriched fraction comprises a quantity of fiber less than or equal to 10% by weight, preferably a quantity of 0.5 to 10% by weight, more preferably 1 to 8% by weight, relative to the total weight of dry matter of the fraction; in particular the fraction may comprise a quantity of fiber of 0.5 to 2% by weight, or 2 to 4% by weight, or 4 to 6% by weight, or 6 to 8% by weight, or 8 to 10% by weight, relative to the total weight of dry matter of the fraction.

[0111] Preferably, the collected protein fraction comprises an amount of fat (lipids) less than or equal to 5% by weight, preferably an amount of 0.5 to 5% by weight, more preferably 0.5 to 3% by weight, relative to the total weight of dry matter of the fraction; in particular, the fraction may comprise an amount of fat of 0.5 to 1% by weight, or 1 to 2% by weight, or 2 to 3% by weight, or 3 to 4% by weight, or 4 to 5% by weight, relative to the total weight of dry matter of the fraction.

[0112] The amounts of carbohydrates, protein, fiber and fat can be determined as described above.

[0113] An example of a method according to the invention is shown in Figure 1. In this example, a cereal material 1, in particular oats and / or barley, preferably undergoes a first grinding 2 and a ground fraction 3 is obtained. This ground fraction 3 is subjected to an extraction treatment 4 using an alcohol solution, preferably an ethanol solution. At the end of this extraction 4, a lipid-enriched liquid fraction 5 comprising an alcohol / lipid mixture and a lipid-depleted solid fraction 6 are collected. The lipid-depleted solid fraction 6 is then subjected to a second grinding step 7. The recovered fraction 8 corresponds to a mixture of flour (ground almond) and bran. A separation step 9 of the particles of fraction 8, according to their size, in particular by sieving, is then carried out in order to separate the flour from the bran.Two fractions are collected: the fraction of larger particles corresponds to bran and a fraction enriched in beta-glucans 10 and the fraction of finer particles corresponds to flour and a fraction depleted in beta-glucans 11. The fraction depleted in beta-glucans 11 is subjected to a grinding step 12, preferably micronization, followed by a step of separation of the particles 13 by aeraulic separation. Two fractions are then obtained: a fraction of lighter particles corresponding to a fraction enriched in protein 14 and a fraction of heavier particles corresponding to a fraction enriched in starch 15.

[0114] The invention also relates to a fraction obtained by, or capable of being obtained by, a separation process as described above.

[0115] In particular, the invention also relates to a lipid-enriched fraction obtained by, or capable of being obtained by, a separation method as described above.

[0116] The invention also relates to a fraction enriched in beta-glucans obtained by, or capable of being obtained by, a separation method as described above. The invention also relates to a fraction enriched in proteins obtained by, or capable of being obtained by, a separation method as described above.

[0117] The invention also relates to a starch-enriched fraction obtained by, or capable of being obtained by, a separation process as described above.

[0118] Fractions enriched in lipids, beta-glucans, proteins or starch may be as described above.

[0119] Examples

[0120] The following examples illustrate the invention without limiting it.

[0121] In the examples, the following analysis and measurement methods were used:

[0122] - Measurement of protein quantity: Kjeldahl method using a FOSS titrator according to ISO 5983-2 standard;

[0123] - Measurement of the quantity of lipids: AOAC method 922.06;

[0124] - Measurement of the quantity of carbohydrates (starch): method according to ISO 15914 standard;

[0125] - Measurement of the quantity of total fibers: AOAC 2011 .25 method;

[0126] - Measurement of the quantity of beta-glucan: AOAC method 995.16.

[0127] Example 1: Production of a fraction enriched in beta-qlucan

[0128] 25 kg of coarsely ground oat groats were introduced into a 250 litre Nutsche reactor.

[0129] The reactor is equipped with a 10 pm filter at the bottom of the tank.

[0130] The composition of the oat groats introduced into the reactor is indicated in the table below (in mass percentage).

[0131] [Table 1] 134 kg (170 liters) of dehydrated ethanol was mixed with 30 kg of water to obtain an aqueous ethanol solution with an ethanol concentration of 85% v / v. The ethanol solution was prepared at room temperature.

[0132] The ethanol solution was introduced into the reactor, the mass ratio of ethanol solution to gruel being 6.6:1. The gruel / ethanol solution mixture was kept stirring for 45 minutes at room temperature.

[0133] After this extraction time, the liquid was drained through the 10 µm filter, under constant pressure of 2 bar. The cake was then dried in a vacuum oven at a temperature of 45°C until all traces of ethanol disappeared.

[0134] The ethanol solution containing the fats was distilled in a tray column configured to obtain 96% v / v ethanol at the top of the column. This alcohol can then be recycled in a new extraction.

[0135] Oat oil was recovered at the bottom of the column.

[0136] A second extraction was carried out on the dried cake under the same conditions as the first (i.e., 45 minutes of contact time under stirring with 200 liters of 85% v / v ethanol in water).

[0137] The fat extraction yield is 91% (by weight). A small amount of flour is present in the oil obtained, this flour coming from the passage of particles smaller than 10 pm through the filter of the extraction reactor.

[0138] The lipid balance of the extraction operations is shown in the table below:

[0139] Table 2]

[0140] The deoiled flour was then ground according to the following process. The bran (fibrous outer shell of the oat) is separated using a Buhler MLU 202 mill in soft wheat configuration and 250 μm sieve. The bran fraction obtained from this separation is a fraction enriched in beta-glucans, the white flour fraction remaining after separation of the bran corresponds to a fraction depleted in beta-glucans

[0141] The mass balance of the separation operation is summarized in the table below:

[0142] Table 3]

[0143] The losses are due to a drop in humidity and some traces of powder remaining on the walls of the powder delivery ducts.

[0144] The fiber rate balance given in the table below (in mass percentage relative to the total weight of dry matter (DM)) indicates a near tripling of the beta-glucan rate in the fraction enriched in beta-glucans (bran) compared to the flour obtained after extraction, for a mass yield of the bran fraction of 24.7%

[0145] Table 4]

[0146] Example 2: Production of de-oiled oat flour 25 kg of coarsely ground oat groats were introduced into a Nutsche reactor with a capacity of 250 liters. The reactor is equipped with a 10 μm filter at the bottom of the tank.

[0147] The oatmeal is as described in Example 1.

[0148] A single extraction was carried out under the same conditions as in example 1 (i.e. 45 minutes of contact time, with stirring, with 200 liters of 85% v / v ethanol in water, with a mass ratio of aqueous ethanol solution to gruel of 6.6).

[0149] The oil was separated from the ethanol by distillation, as described in Example 1. The fat extraction yield is 82.8% by weight. A small amount of flour is present in the oil obtained (particles smaller than 10 pm).

[0150] The lipid balance of the extraction operation is shown in the table below:

[0151] Table 5]

[0152] Example 3: Production of de-oiled oat flour

[0153] 25 kg of coarsely ground oat groats were introduced into a 250 litre Nutsche reactor. The reactor is equipped with a 10 µm filter at the bottom of the tank.

[0154] The oatmeal is as described in Example 1.

[0155] 100.6 kg (127.3 liters) of dehydrated ethanol was mixed with 22.5 kg of water to obtain an aqueous ethanol solution with an alcohol concentration of 85% v / v. The ethanol solution was prepared at room temperature.

[0156] The ethanol solution was introduced into the reactor, the mass ratio of ethanol solution to gruel being 4.9:1. The gruel / ethanol solution mixture was kept stirring for 45 minutes at room temperature.

[0157] After this extraction time, the liquid was drained through the 10 µm filter. The operation was carried out under constant pressure of 2 bar. The cake was then dried in a vacuum oven at a temperature of 45°C until all traces of ethanol disappeared.

[0158] The ethanol solution containing the fats was distilled in a tray column configured to obtain 96% v / v ethanol at the top of the column. This alcohol can then be recycled to carry out a new extraction.

[0159] The oat oil was recovered at the bottom of the column.

[0160] The fat extraction yield is 80.7% by weight. A small amount of flour is present in the oil obtained.

[0161] The lipid balance of the extraction operation is shown in the table below:

[0162] Table 6]

[0163] Example 4: Production of de-oiled oat flour

[0164] 25 kg of coarsely ground oat groats were introduced into a 250 litre Nutsche reactor. The reactor is equipped with a 10 µm filter at the bottom of the tank.

[0165] The gruel is as described in Example 1. 74 kg (93.7 liters) of dehydrated ethanol was mixed with 18.6 kg of water to obtain an aqueous ethanol solution with an alcohol concentration of 83% v / v. The ethanol solution was prepared at room temperature.

[0166] The ethanol solution was introduced into the reactor, the mass ratio of ethanol solution to gruel being 3.7:1. The gruel / ethanol solution mixture was kept stirring for 30 minutes at room temperature.

[0167] After this extraction time, the liquid was drained through the 10 µm filter. The operation was carried out under constant pressure of 2 bar. The cake was then dried in a vacuum oven at a temperature of 45°C until all traces of ethanol disappeared.

[0168] The ethanol solution containing the fats was distilled in a tray column configured to obtain a 96% v / v alcohol. This alcohol can then be recycled to carry out a new extraction.

[0169] Oat oil was recovered at the bottom of the column.

[0170] The fat extraction yield is 77.2% by weight. A small amount of flour is found in the oil obtained.

[0171] The lipid balance of the extraction operation is shown in the table below:

[0172] Table 7]

[0173] Example 5: Production of a protein-enriched fraction and a starch-enriched fraction

[0174] The white flour fraction (oat flour without bran) obtained in Example 1 was micronized using a grinder and then subjected to cyclonic aeraulic separation (turbo-separation). The lighter protein-enriched fraction (called the protein fraction) was collected at the top of the cyclone while the heavier starch-enriched fraction (called the starch fraction) was collected at the bottom of the cyclone. The details of the equipment are given below:

[0175] - ZPS crusher (70ZPS+70 ATP, Hosokawa-Alpine®):

[0176] - Grinder speed: 14,000 rpm

[0177] - Chicane orientation: face

[0178] - Air flow: 100 m 3 / h

[0179] - Power supply: 105 rpm

[0180] - Selector speed: 3,800 rpm

[0181] - 70 ATP turboseparator (Hosokawa-Alpine®)

[0182] - Air flow: 100 m 3 / h

[0183] - Power supply: 105 rpm

[0184] - Selector speed: 9,000 rpm

[0185] The mass balance of the operation is summarized in the table below:

[0186] Table 8]

[0187] The losses are due to a drop in humidity and some traces of powder remaining on the walls of the powder delivery ducts.

[0188] The protein and carbohydrate balance given in the table below (in mass percentage relative to the total weight of dry matter (DM)) indicates an increase of 35% in the protein level in the protein fraction compared to the white flour fraction, for a mass yield of the fraction of 30.3%,

[0189] Table 9] Example 6: Production of a protein-enriched fraction and a starch-enriched fraction

[0190] The white flour fraction (oat flour without bran) obtained in Example 1 was micronized using a grinder and then subjected to cyclonic aeraulic separation (turbo-separation). The lighter protein fraction was collected at the top of the cyclone while the heavier starch fraction was collected at the bottom of the cyclone. The equipment and operating conditions used to carry out these steps are the same as those indicated in Example 5, with the exception of the turboseparator selector speed, which is 12,000 rpm.

[0191] The mass balance of the operation is summarized in the table below:

[0192] Table 10]

[0193] The losses are due to a drop in humidity and some traces of powder remaining on the walls of the powder delivery ducts.

[0194] The protein and carbohydrate balance given in the table below (in mass percentage relative to the total weight of dry matter (DM)) shows that the protein level has doubled in the protein fraction compared to the white flour fraction, for a mass yield of the fraction of 12.0%.

[0195] Table 11 ]

Claims

Claims 1. Process for separating a cereal material, comprising the following steps: - the provision of at least one cereal material (1) comprising starch, proteins, lipids and beta-glucans; - treatment of the cereal material by solid / liquid extraction (4) with an alcohol solution comprising at least 50% by volume of alcohol, so as to obtain a solid fraction depleted in lipids (6) and a liquid fraction enriched in lipids (5); - grinding (7) of the solid fraction depleted in lipids (6); - the separation (9) of the particles of the crushed lipid-depleted fraction (8) according to their size, so as to obtain a fraction enriched in beta-glucans (10) and a fraction depleted in beta-glucans (11); - grinding (12) of the fraction depleted in beta-glucans (11); and - the treatment of the fraction depleted in crushed beta-glucans by aeraulic separation (13), so as to obtain a fraction enriched in proteins (14) and a fraction enriched in starch (15).

2. Method according to claim 1, in which the cereal material (1) is a cereal material of oats and / or barley.

3. Method according to claim 1 or 2, in which the cereal material (1) is at least one cereal grain and / or at least one product from the malting, malt extract manufacturing, brewing, cereal distillation, vegetable dairy and / or milling industries.

4. Method according to one of claims 1 to 3, in which the alcohol solution is a mixture of alcohol and at least one solvent, the solvent preferably being chosen from the group of water, 2-methyloxolane and mixtures thereof, plus preferably the alcohol solution consists of a mixture of alcohol and water.

5. Method according to one of claims 1 to 4, in which the alcohol solution comprises from 50 to 90% by volume of alcohol.

6. Method according to one of claims 1 to 5, in which the alcohol of the alcohol solution is a recycled alcohol.

7. Method according to one of claims 1 to 6, in which the alcohol of the alcohol solution is ethanol.

8. Method according to one of claims 1 to 7, in which the grinding (12) of the fraction depleted in beta-glucans (10) comprises the micronization of the fraction depleted in beta-glucans (10).

9. Method according to one of claims 1 to 8, in which the separation (9) of the particles of the crushed lipid-depleted fraction (8) according to their size is carried out by sieving.

10. Method according to one of claims 1 to 9, further comprising a step of separating the alcohol from the lipid-enriched liquid fraction, preferably by distillation, the method preferably further comprising a step of recycling the separated alcohol for the solid / liquid extraction step (4).

11. Method according to one of claims 1 to 10, further comprising, before the step of treating the cereal material by solid / liquid extraction, a step of grinding (2) and / or flattening the cereal material, so as to obtain a ground (3) and / or flattened fraction, the cereal material (1) provided preferably being a cereal grain.

12. Method according to claim 11, in which the cereal material (1) is a cereal grain comprising a film, the method further comprising a step of dehulling the grain prior to the step of grinding (2) and / or flattening the cereal material (1).

13. Method according to one of claims 1 to 12, in which the fraction enriched in beta-glucans (11) comprises a quantity of beta-glucan greater than or equal to 10% by weight, preferably 10 to 40% by weight, more preferably 15 to 25% by weight, relative to the total weight of dry matter of the fraction.

14. Method according to one of claims 1 to 13, in which the starch-enriched fraction (15) comprises a quantity of carbohydrates greater than or equal to 40% by weight, preferably 40 to 90% by weight, more preferably 50 to 85% by weight, relative to the total weight of dry matter of the fraction.

15. Method according to one of claims 1 to 14, in which the protein-enriched fraction (14) comprises a quantity of proteins greater than or equal to 15% by weight, preferably 15 to 35% by weight, more preferably 15 to 30% by weight, more preferably 20 to 30% by weight, relative to the total weight of dry matter in the fraction.

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