Process for separating cereal matter into fractions respectively enriched in beta-glucan, proteins, lipids and starch.

Abstract

The invention relates to a process for separating a cereal material, comprising the following steps: supplying 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 aerodynamic separation (13), so as to obtain a protein-enriched fraction (14) and a starch-enriched fraction (15). Figure for the abbreviation: figure 1.

Description

Title of the invention: Process for separating a cereal material into fractions respectively enriched in beta-glucan, proteins, lipids and starch. Field of invention

[0001] 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. Technical background

[0002] 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.

[0003] Beta-glucans are known for their biological and functional properties that are beneficial to health. 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.

[0004] Oats and barley, as well as co-products from these cereals and from maltings, breweries and vegetable dairies, are known to contain high levels of beta-glucan. Among the major cereals (wheat, rye, oats and barley), oats and barley are those whose grains contain the highest amounts of beta-glucans. Oat and barley grains are made up of 4 main components: • 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. • Bran: This is the protective covering (outer layer) of the seed. This part is very rich in fiber and beta-glucan. • The almond: this is the heart of the seed without its protective covering. The operation of removing the covering from the grain is called hulling. The ground almond is known as flour. • The endosperm: this is the main part of the almond. It contains carbohydrates in the form of starch and proteins. • The germ: this is the smallest part of the almond. It contains most of the grain's fat.

[0005] Oat beta-glucans are found in the endosperm and its husk. Therefore, the whole grain must be hulled and fractionated to produce commercial bran enriched with beta-glucans. By 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.

[0006] Products and co-products from the use of oats and barley, particularly in malting, brewing, distillation, vegetable dairying and milling, are also rich in beta-glucans.

[0007] Diets that include soluble fiber from certain foods and are low in saturated fatty acids and cholesterol may reduce the risk of coronary heart disease. Recent studies have determined that beta-glucan is the physiologically active component responsible for the cholesterol-lowering effect that has been observed with oat consumption. The health claim that regular consumption of beta-glucan reduces cholesterol levels and the risk of coronary heart disease is currently authorized by the US FDA (Food and Drug Administration) and the EFSA (European Food Safety Authority).

[0008] Beta-glucans are linear, unbranched, non-starchy 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.

[0009] Beta-glucans from cereals have also been shown to reduce the glycemic response, which could help improve metabolic regulation in diabetics.

[0010] Cereals, and in particular barley and oats (including products and co-products derived from the use of these 2 cereals), contain other constituents having They also have interesting nutritional and functional characteristics such as proteins, starch and oil (lipids). All these compounds find applications in food as well as in pharmacy or cosmetics.

[0011] Furthermore, in Commission Implementing Regulation (EU) No 828 / 2014 of 30 July 2014, the European Union recognises 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 constitute an interesting alternative to wheat proteins traditionally used in food.

[0012] The use of different 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 resulting from the use of these two cereals, is unfortunately almost impossible due to a high fat content in the grains and the products resulting 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.

[0013] In order to be able to fractionate oat or barley grain or the products and co-products resulting 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 beta-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 then subjected to air separation.

[0014] However, the use of this solvent has several major drawbacks. First of all, it is produced from petroleum, resulting in high greenhouse gas emissions (e.g., 620 kg CO2eq / t). In addition, its degree of toxicity is high and after extraction, hexane residues are always present in the grain subjected to treatment.

[0015] 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.

[0016] 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 grinding of the defatted fraction, a step of separating the fraction obtained into a fraction enriched in starch and a fraction enriched in beta-glucan and a step of separation by sieving or by aeraulic separation of the fraction enriched in starch to obtain 3 fractions: a fraction comprising a protein concentrate, one comprising a beta-glucan concentrate and a fraction comprising a starch concentrate.

[0017] 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 larger particle fraction obtained is subjected to milling and a second step of aeraulic separation to obtain a fraction enriched in beta-glucans. The finer particle fraction obtained at the end of the first step of aeraulic separation is also subjected to another step of aeraulic separation to obtain a fraction enriched in proteins and a fraction enriched in starch.

[0018] Furthermore, the currently used methods for extracting cereal beta-glucans may result in certain negative effects that may alter their properties and functionality. For example, they may alter their native structure, which may reduce their ability to form a viscous gel in the intestinal tract. This loss of structure may result in a decrease in their beneficial effects, such as cholesterol reduction and blood sugar regulation.

[0019] There is therefore a real need to develop a process for obtaining fractions enriched, respectively, in oil (or lipids), in starch, in protein and in beta-glucan from cereals, leading to low denaturation of the components to be isolated and in particular of the beta-glucans and proteins, and having a lower greenhouse gas emission. Summary of the invention

[0020] The invention relates firstly to a method for separating a cereal material, comprising the following steps: • the supply of at least one cereal material comprising starch, proteins, lipids and beta-glucans; • 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; • grinding of the solid fraction depleted in lipids; • 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; • grinding of the fraction depleted in beta-glucans; and • 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.

[0021] In embodiments, the cereal material is an oat and / or barley cereal material.

[0022] 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, vegetable dairy and / or milling industries.

[0023] 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.

[0024] In embodiments, the alcohol solution comprises from 50 to 90% by volume of alcohol.

[0025] In embodiments, the alcohol of the alcohol solution is a recycled alcohol.

[0026] In embodiments, the alcohol of the alcohol solution is ethanol.

[0027] In embodiments, grinding the beta-glucan-depleted fraction includes micronization of the beta-glucan-depleted fraction.

[0028] In embodiments, separation of particles from the milled lipid-depleted fraction according to their size is carried out by sieving.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] In embodiments, the beta-glucan enriched fraction comprises an amount of beta-glucan greater than or equal to 10% by weight, preferably from 10 to 40 % by weight, more preferably from 15 to 25% by weight, relative to the total weight of dry matter of the fraction.

[0033] 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.

[0034] In embodiments, the protein-enriched fraction comprises a protein amount 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.

[0035] 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.

[0036] 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.

[0037] In particularly advantageous embodiments, in which the alcohol, and in particular the 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. Brief description of the figures

[0038] [Fig.l] represents a flowchart of an example of a method according to the invention. Detailed description

[0039] The invention is now described in more detail and in a non-limiting manner in the following description.

[0040] Unless otherwise indicated, all percentages are mass percentages.

[0041] 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.

[0042] In the present 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 greater than that of the fraction before treatment.

[0043] In this text, the terms “lipids”, “oil” and “fats” have the same meaning and are used interchangeably.

[0044] 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, the term "cereal material" means any material based on, or derived from, at least one cereal, in any possible form (for example, 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.

[0045] The method according to the invention involves a step of deoiling 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.

[0046] Cereals are part of the Poaceae family. They produce grains, which include starch, proteins, lipids and soluble fibers, in particular beta-glucans. Generally, cereal grains include at least one kernel surrounded by a husk. However, in this text, the term "grain" can generally refer to the total (whole) grain as well as any part of the grain (for example, the grain without its glumes, or the kernel, etc. unless otherwise indicated.

[0047] 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.

[0048] In the present invention, any suitable cereal material, including starch, proteins, lipids and beta-glucans, may be used.

[0049] 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), except otherwise indicated. Oat and barley grains have the advantage of being rich in beta-glucan (they can contain 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 hull and a groat, is used as the starting raw material.

[0050] Alternatively or additionally, any product resulting from the use or processing of a cereal (in particular oats or barley) may advantageously be used as starting cereal material, in particular in fermentation and distillation processes, for the production of germinated 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: • 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. • 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. • 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. • Milling products.

[0051] 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.

[0052] 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.

[0053] The de-skinning can be carried out using any suitable device, in particular using one of the mechanical forces mentioned above, in particular abrasion. Advantageously, dehulling is carried out using a deburrer. Deburrers operate on the principle of a friction polishing machine. They can be used to remove beards, debind double grains, and treat the surface of cereal grains. In an example of a dehulling process using a deburrer, a feed screw transports the cereals into the working chamber, where a rotor in a perforated sleeve subjects the treated product to mechanical frictional forces. 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 treated product (the grain), such as beards or impurities adhering to the surface, can exit the machine through a separate suction outlet.

[0054] The use of a deburrer to perform the dehulling is advantageous since the deburrer cleans the surface of the grain at the same time as it detaches the skin from the grain by mechanical stress. In addition, this treatment step makes it possible to improve the flow properties of the grains.

[0055] 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.

[0056] 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).

[0057] The flattening may be carried out using a cereal flattener, preferably using mechanical compression force. This flattening step is preferably carried out when the cereal material used is a cereal grain.

[0058] 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 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 chosen 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.

[0059] 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 (relative to 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.

[0060] 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.

[0061] 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. 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 on a 10 μm mesh cloth.

[0062] 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 process 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 the introduction into the hydrolyzed starch fluid of one or more glucosidase and / or saccharidase enzymes. The use of such a process to prepare the fermentation substrate for the production of ethanol has the advantage of having a relatively low greenhouse gas emission rate, which may be less than 400 kg of CO2eq / t of ethanol

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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).

[0067] 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.

[0068] In a particularly advantageous manner, 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.

[0069] The process 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 aim of these steps is to separate the beta-glucan fraction of the starch and protein fractions. For grinding, any suitable type of grinder can be used, including 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. After grinding, a mixture of fragments of the shell (mainly fibers) (also called bran in this text) and almond powder (also called flour in this text) is obtained.

[0070] The step of separating the particles obtained after grinding is preferably carried out by sieving. In particular, the particles may be separated by passing them over a sieve with a suitable mesh size for separating the bran from the flour. For example, particles with a size less than a size of between 200 and 600 mm may be separated from bran with a size greater than or equal to such a size. The bran separated during this step corresponds to a fraction enriched in beta-glucans; the flour obtained after separation corresponds to a fraction depleted in beta-glucans.

[0071] 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.

[0072] Preferably, the beta-glucan-enriched fraction comprises a protein quantity of less than or equal to 30% by weight, preferably a quantity 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 weight of dry matter of the fraction). In embodiments, the protein quantity in the beta-glucan-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, or 15 to 20% by weight, or 20 to 30% by weight, relative to the total weight of dry matter of the fraction. The amount of protein can be measured according to ISO 5983-2 (Kjeldahl method).

[0073] Preferably, the fraction enriched in beta-glucans comprises a quantity of beta-glucan greater than or equal to 10% by weight, preferably a quantity 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 a quantity 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 AO AC 995.16 method.

[0074] Preferably, the fraction enriched in beta-glucan 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 can be measured according to the method AO AC 922.06.

[0075] 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.

[0076] Particularly advantageously, this grinding comprises, or is, micronization, preferably by dry means. The ground fraction obtained is then a micronized fraction.

[0077] The micronization step allows the proteins to be separated from the starch granules to allow their subsequent separation.

[0078] By "micronization" is meant a grinding allowing the obtaining of particles with a volume median diameter of less than 100 pm, preferably less than 50 pm, more preferably less than 30 pm. The volume median diameter (D50) of the particles can be measured according to standard NF ISO 13320-1.

[0079] Micronization can be carried out by any suitable mill (in particular, any mill using mechanical forces of abrasion, compression, impact or shear). For example, a mill using impact force can be used.

[0080] Micronization is very preferably carried out at room temperature (i.e. between 15 and 30°C).

[0081] 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.

[0082] 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.

[0083] 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. “Starch-enriched and protein-depleted fraction” means a fraction in which the starch / protein molar ratio (on a dry basis) is higher than that of the fraction subjected to purification. “Protein-enriched and starch-depleted fraction” means a fraction in which the protein / starch molar ratio (on a dry basis) is higher than that of the fraction subjected to purification.

[0084] 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) carrying 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).

[0085] Preferably, the starch-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 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 quantity 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.

[0086] Preferably, the starch-enriched fraction comprises a quantity of protein 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 quantity of protein in the recovered starch-enriched fraction may be, relative to the total weight of dry matter of the fraction, from 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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 weight of dry matter of the fraction). In embodiments, the amount of carbohydrates in the recovered protein-enriched fraction may be, relative to the total weight of dry matter 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.

[0091] 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 an amount 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.

[0092] Preferably, the collected protein 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.

[0093] The amounts of carbohydrate, protein, fiber and fat can be determined as described above.

[0094] An example of a method according to the invention is shown in [Fig. 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 almonds) 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.

[0095] The invention also relates to a fraction obtained by, or capable of being obtained by, a separation process as described above.

[0096] In particular, the invention also relates to a lipid-enriched fraction obtained by, or capable of being obtained by, a separation process as described above.

[0097] The invention also relates to a fraction enriched in beta-glucans obtained by, or capable of being obtained by, a separation process as described above.

[0098] The invention also relates to a protein-enriched fraction obtained by, or capable of being obtained by, a separation process as described above.

[0099] The invention also relates to a starch-enriched fraction obtained by, or capable of being obtained by, a separation process as described above.

[0100] The fractions enriched in lipids, beta-glucans, proteins or starch may be as described above. Examples

[0101] The following examples illustrate the invention without limiting it.

[0102] In the examples, the following analysis and measurement methods were used: • Measurement of protein quantity: Kjeldahl method using a FOSS titrator according to ISO 5983-2 standard; • Measurement of the quantity of lipids: method AO AC 922.06; • Measurement of the quantity of carbohydrates (starch): method according to the ISO standard 15914; • Measurement of the quantity of total fibers: AO AC 2011.25 method; • Measurement of the quantity of beta-glucan: AO AC 995.16 method.

[0103] Example 1: Production of a fraction enriched in beta-glucan

[0104] 25 kg of coarsely ground oat groats were introduced into a reactor of Nutsche reactor type with a capacity of 250 liters.

[0105] The reactor is equipped with a 10 pm filter at the bottom of the tank.

[0106] The composition of the oat groats introduced into the reactor is indicated in the table below (in mass percentage).

[0107] [Tableauxl] Moisture 12.0% Protein 11.1% Fat 5.8% Carbohydrate 58.9% Fiber 10.8% Ash 1.4%

[0108] 134 kg (170 liters) of dehydrated ethanol were mixed with 30 kg of water in order to to obtain an aqueous ethanol solution with an ethanol concentration of 85% v / v. The ethanol solution was prepared at room temperature.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] The oat oil was recovered at the bottom of the column.

[0113] 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).

[0114] 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.

[0115] The lipid balance of the extraction operations is indicated in the table below:

[0116] [T ables 2] Quantity (kg) Fat (% by weight) Quantity of fat (kg) Oil yield from extraction (%) Oatmeal 25 5.8 1.45 Oil collected after first extraction 1.13 77.9 Oil collected after second extraction 0.19 91.0 De-oiled flour obtained after first extraction 23.87 1.3 0.31 De-oiled flour obtained after second extraction 23.68 0.5 0.12

[0117] The deoiled flour was then ground according to the following process. The bran (fibrous outer shell of the oats) 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

[0118] The mass balance of the separation operation is summarized in the table below:

[0119] [Tables 3] Mass balance (% by weight) Bran fraction 24.7 White flour fraction 73.8 Losses 1.5

[0120] The losses are due to a drop in humidity and some traces of powder remaining on the walls of the powder conveying ducts.

[0121] The balance of the fiber rate 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%

[0122] [Tables4] Total fiber content (TDF) (% / MS) Beta-glucan content (% / MS) Deoiled oat flour 10.6 5.1 Bran fraction 26.3 14.9 White flour fraction 5.3 2.2

[0123] Example 2: Production of de-oiled oat flour

[0124] 25 kg of coarsely ground oat groats were introduced into a reactor of Nutsche reactor type with a capacity of 250 liters. The reactor is equipped with a 10 pm filter at the bottom of the tank.

[0125] The oatmeal is as described in Example 1.

[0126] 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 ethanol at 85% v / v in water, with a mass ratio of aqueous ethanol solution to gruel of 6.6).

[0127] 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 μm).

[0128] The lipid balance of the extraction operation is indicated in the table below:

[0129] [Tables5] Quantity (kg) Fat (% by weight) Quantity of fat (kg) Oil yield from extraction (%) Oatmeal 25 5.8 1.45 Oil collected after extraction 1.20 82.8 Deoiled flour 23.8 1.0 0.24

[0130] Example 3: Production of de-oiled oat flour

[0131] 25 kg of coarsely ground oat groats were introduced into a reactor of Nutsche reactor type with a capacity of 250 liters. The reactor is equipped with a 10 pm filter at the bottom of the tank.

[0132] The oatmeal is as described in Example 1.

[0133] 100.6 kg (127.3 liters) of dehydrated ethanol were mixed with 22.5 kg of water in order to to obtain an aqueous ethanol solution with an alcohol concentration of 85% v / v. The ethanol solution was prepared at room temperature.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] The oat oil was recovered at the bottom of the column.

[0138] The fat extraction yield is 80.7% by weight. A small amount of flour is present in the oil obtained.

[0139] The lipid balance of the extraction operation is indicated in the table below:

[0140] [Tables] Quantity (kg) Fat (% by weight) Quantity of fat (kg) Oil yield from extraction (%) Oatmeal 25 5.8 1.45 Oil collected after extraction 1.17 80.7 Deoiled flour 23.83 1.1 0.26

[0141] Example 4: Production of deoiled oat flour

[0142] 25 kg of coarsely ground oat groats were introduced into a reactor of Nutsche reactor type with a capacity of 250 liters. The reactor is equipped with a 10 pm filter at the bottom of the tank.

[0143] The oatmeal is as described in Example 1.

[0144] 74 kg (93.7 liters) of dehydrated ethanol were mixed with 18.6 kg of water in order to to obtain an aqueous ethanol solution with an alcohol concentration of 83% v / v. The ethanol solution was prepared at room temperature.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] The oat oil was recovered at the bottom of the column.

[0149] The fat extraction yield is 77.2% by weight. A small amount of flour is found in the oil obtained.

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

[0151] [Tables 7] Quantity (kg) Fat (% by weight) Quantity of fat (kg) Oil yield from extraction (%) Oatmeal 25 5.8 1.45 Oil collected after extraction 1.12 77.2 Deoiled flour 23.88 1.3 0.31

[0152] Example 5: Production of a protein-enriched fraction and a starch-enriched fraction

[0153] 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 protein fraction) was collected at the top of the cyclone while the heavier starch-enriched fraction (called starch fraction) was collected at the bottom of the cyclone. The details of the equipment are given below: • ZPS crusher (70ZPS+70 ATP, Hosokawa-Alpine®): • Grinder speed: 14,000 rpm • Chicane orientation: face • Air flow: 100 m3 / h • Power supply: 105 rpm • Selector speed: 3,800 rpm • 70 ATP turboseparator (Hosokawa-Alpine®) • Air flow: 100 m3 / h • Power supply: 105 rpm • Selector speed: 9,000 rpm

[0154] The mass balance of the operation is summarized in the table below:

[0155] [Tables8] Mass balance (% by weight) Protein fraction 30.3 Starch fraction 66.8 Losses 2.9

[0156] The losses are due to a drop in humidity and some traces of powder remaining on the walls of the powder conveying ducts.

[0157] 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%,

[0158] [Tables9] Protein content (% / MS) Carbohydrate content (% / MS) White flour fraction 11.8 78.0 Protein fraction 15.9 74.0 Starch fraction 10.1 79.8

[0159] Example 6: Production of a protein-enriched fraction and a starch-enriched fraction

[0160] 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 speed of the turboseparator selector which is 12,000 rpm.

[0161] The mass balance of the operation is summarized in the table below:

[0162] [Tables 10] Mass balance (% by weight) Protein fraction 12.0 Starch fraction 85.9 Losses 2.1

[0163] The losses are due to a drop in humidity and some traces of powder remaining on the walls of the powder conveying ducts.

[0164] 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%.

[0165] [Tableauxll] Protein content (% / MS) Carbohydrate content (% / MS) White flour fraction 11.8 78.0 Protein fraction 23.4 68.3 Starch fraction 10.3 79.3

Claims

Claims

1. A method for separating a cereal material, comprising the following steps: • providing at least one cereal material (1) comprising starch, proteins, lipids and beta-glucans; • 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); • separating (9) the particles of the ground lipid-depleted fraction (8) 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 • 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. A method according to claim 1, wherein the cereal material (1) is an oat and / or barley cereal material.

3. A method according to claim 1 or 2, wherein 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, more preferably the alcohol solution consists of a mixture of alcohol and water.

5. A method according to any one of claims 1 to 4, wherein the alcohol solution comprises from 50 to 90% by volume of alcohol.

6. A method according to one of claims 1 to 5, wherein the alcohol in the alcohol solution is recycled alcohol.

7. A method according to one of claims 1 to 6, wherein the alcohol of the alcohol solution is ethanol.

8. A method according to one of claims 1 to 7, wherein the grinding (12) of the beta-glucan-depleted fraction (10) comprises micronizing the beta-glucan-depleted fraction (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. A 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. A method according to claim 11, wherein the cereal material (1) is a cereal grain comprising a skin, 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. A method according to any one of claims 1 to 14, wherein the protein-enriched fraction (14) comprises a quantity of protein greater than or equal to 15% by weight, preferably from 15 to 35 % by weight, more preferably from 15 to 30% by weight, more preferably from 20 to 30% by weight, relative to the total weight of dry matter of the fraction.

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