Method for treating flax seeds with a view to improving the food value of same

Abstract

The present invention concerns a method for treating seeds of flax (Linum usitatissimum) with a view to improving the food value of same, in particular for animals, characterised by the fact that it comprises the following series of steps: a) Using flax seeds on condition that said seeds have a fat and / or Omega 3 fatty acid content higher than predefined values; and, only when the seeds are intended as food for monogastrics, a value in terms of water retention capacity or a low-value nutritional component lower than predefined values; b) Mixing, if there are at least two raw materials of different nature and / or quality, then fractionating, or fractionating then mixing, said seeds from step a); c) Implementing a thermal preparation step for preparing the seeds from step b) with steam and / or a water-based liquid; d) Pressurising the seeds or the mixture from step c) at a minimum pressure of 10 bars; and / or d bis) Heating the seeds or the mixture from step d), or c).

Description

[0001] i

[0002] METHOD FOR TREATMENT OF FLAX SEEDS WITH A VIEW TO IMPROVING THEIR

[0003] VALORISATION AS FOOD

[0004] FIELD OF INVENTION

[0005] The present invention relates to a process for treating flax seeds in order to improve their value as food, particularly for animals.

[0006] TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0007] In human nutrition, it is accepted that the French population's fat intake is now quantitatively in line with recommended daily allowances, but it remains qualitatively unbalanced, particularly with regard to essential fatty acids (omega-3 fatty acids). Indeed, alpha-linolenic acid (ALA) consumption averages only 0.8g per person per day, whereas the recommendation issued by ANSES in 2010 is 2g. At the same time, linoleic acid (LA) consumption is approximately at the recommended daily allowance level, resulting in an excessive LA / ALA ratio.

[0008] To ensure an optimal intake of essential fatty acids for consumers, it is possible to influence the choice of foods that make up our daily meals. But it is also possible to choose foods from which the animal production methods have themselves been modified.

[0009] Indeed, it is now well established that when animals ingest more ALA, more of that ALA is found in products such as meat, eggs, and dairy. Therefore, a key challenge lies in providing animals with digestible, effective, and safe sources of ALA. The animal will then utilize the ingested fatty acids, depositing them in its tissues or metabolizing them into various cellular mediators that play a role in the immune, inflammatory, and reproductive systems, for example.

[0010] Omega-3 fatty acids are considered essential and indispensable because animals, including humans, cannot synthesize them. Therefore, humans must obtain them from their diet for metabolic balance and health. Thus, what is described below for animals is also true for humans. In the following text and claims, it is important to understand that humans are monogastric mammals, like dogs and cats.

[0011] I. Background of the present invention

[0012] A. Expectations in the sectors

[0013] Since the release of the "Recommended Nutritional Intakes" published by ANSES (formerly AFSSA) in 2001, expressing the essential nature of Omega 3 fatty acids, and in particular ALA, for our physiological needs but also their insufficient consumption,

[0014] 1) Many dieticians, doctors and other prescribers of a healthy and balanced diet have spread this message to consumers;

[0015] 2) Numerous scientific studies have also shown the effect of the choice of dietary fatty acids in the ration of animals on the quality of the lipid profile of animal-derived products.

[0016] Each link in the food supply chain expresses expectations that can be summarized as follows:

[0017] - Farmers: to seek crop rotation partners to lengthen crop rotations, thereby limiting the pressure of diseases and pests, facilitating weed control, reducing the use of nitrogen fertilizers to ultimately make their production system more robust;

[0018] - For livestock farmers: optimizing the performance of their production tools by maximizing feed ration utilization, producing healthy and productive animals, and also increasing the profitability of their products by seeking to add value. This is the case, for example, with official quality labels such as organic farming, Label Rouge, PDOs, AOCs, or with sectors such as the "Bleu-Blanc-Cœur" (registered trademark) which promotes products with a better nutritional profile through, for example, specific specifications.

[0019] - Consumers: consuming safe, healthy, natural foods with low GMO content, sourced locally, and with proven nutritional and health benefits, all within the framework of sustainable food. But there are other, more significant ones, expressed by:

[0020] - Institutional actors who want to limit the use of imports of oilseeds, nitrogen fertilizers and pesticides, and increase French and European production of crops of interest;

[0021] - Companies across the entire food industry, seeking differentiation and added value in a tense economic context;

[0022] - Para-agricultural businesses forming part of a large network of services and products.

[0023] B. The potential of an integrated solution: flaxseed. While this solution potentially meets all the expectations of the sectors, it may nevertheless be limiting in certain respects.

[0024] First, the potential benefits of flaxseed are outlined below. Then, its limitations will be described.

[0025] 1. A solution for crops

[0026] The integration of flax cultivation into crop rotations is interesting from an agronomic point of view, both in conventional and organic systems, and for both winter and spring sowing strategies.

[0027] This culture contributes to

[0028] - diversify the rotations and lengthen them;

[0029] - reduce the use of inputs: nitrogen fertilizers, plant protection products, potash, phosphorus...

[0030] - to increase the yield of subsequent crops, thanks to diversification and the structuring effect of roots at soil level.

[0031] 2. A solution for food

[0032] Monogastric animals, such as broiler and laying hens, or pigs raised for meat, have, by definition, only one stomach. Due to their digestive physiology, there is a very good correlation between ingested Omega-3 fatty acids and those deposited in products intended for human consumption (Lessire 2001).

[0033] Ruminants, or polygastric animals, have the unique characteristic of possessing four stomachs, one of which is called the rumen. The rumen has the capacity to biohydrogenate a significant portion of Omega-3 fatty acids, meaning that the Omega-3s are saturated and isomerized into other saturated or unsaturated fatty acids.

[0034] Fortunately, ruminants are naturally big consumers of Omega 3, since it is found in large quantities in grass, which allows them to find enough at the exit of the rumen, and thus, some of the Omega 3 can also be fixed in the tissues and also serve the different metabolic processes of interest for the health of the animal.

[0035] However, the hydrolyzed and then degraded Omega-3 fatty acids in the rumen into a large number of different fatty acids will also have a beneficial effect on the rumen bacterial population, notably by reducing protozoa and promoting cellulolytic flora. This will lead to two significant consequences: the synthesis of hydrogen-producing acetic acid will decrease, while the synthesis of hydrogen-consuming propionic acid will increase. These factors will induce, on the one hand, a reduction in the de novo synthesis of saturated fatty acids present in milk or meat and, on the other hand, a reduction in enteric methane emissions into the environment.

[0036] Thus, the objective is not necessarily to completely protect Omega 3 from ruminal degradation, but rather to find a fair balance, as a grass-based diet allows.

[0037] Whether for ruminants or monogastric animals, their diet is deficient in AGPIn-3 (due to the massive use of soy and corn, sources of Omega-6, in animal feed, and the reduced use of grass for ruminants). Yet, their metabolism requires Omega-3 in the form of alpha-linolenic acid (ALA). While some raw materials can contribute to its intake (grass, alfalfa, rapeseed), it is not feasible to provide the necessary quantities without using a more concentrated source of Omega-3.

[0038] In this context, flaxseed stands out as a leader given its lipid content and its fatty acid profile similar to that of grass, with approximately 55% of fatty acids in the form of ALA.

[0039] Flax seeds are therefore an important source of energy, in the form of lipids and Omega-3 fatty acids, whose nutritional and health benefits, known to humans, are applicable to some extent to animal nutrition and health. a) Nutritional values

[0040] The nutritional values ​​of flaxseed according to the INRA food tables are presented in the table below, in comparison to rapeseed.

[0041]

[0042] (Source: Table of composition and nutritional value of raw materials intended for livestock, INRA, 2002)

[0043] It can thus be observed that flaxseed is less rich in lipids and energy than rapeseed, and that this energy is less efficiently utilized by pigs, roosters, and ruminants. Indeed, based on the gross energy content of flaxseed, pigs, roosters, and ruminants utilize only 72% of this energy as digestible energy (for pigs), 59% as metabolizable energy (for roosters), and 67% (for ruminants), compared to 83%, 70%, and 71% respectively for rapeseed. It should be added that rapeseed requires technological processing to achieve the values ​​mentioned above (Leclercq et al., 1989).

[0044] Thus, while flaxseeds have interesting nutritional potential, they remain underutilized by various animal species, as evidenced by their low digestible and metabolizable energy values. Furthermore, another way to assess the digestibility of flaxseed is to measure fat availability. Indeed, the majority of the energy contained in the seed is in the form of fat. And as we will see later, a limitation to digestibility lies in the low accessibility of the seed's fat. Hence the interest in evaluating this digestibility, usually measured in vivo in dedicated experimental farms, by an in vitro measurement of the seed's fat availability.

[0045] Thus, depending on the treatments applied to the seed, a simple measurement of available fat (AF) allows for comparison of treatments and prediction of digestibility, as demonstrated in the articles by Noblet et al. (2008) on pigs, and Chesneau et al. (2009) on ruminants. b) Measurement of available fat (AF)

[0046] This internal method relies on evaluating the proportion of fat extracted in a solvent after a predetermined period. The aim of this assay is to mimic the gradual, step-by-step release of fat into the different compartments of the animal's digestive tract.

[0047] In short, the dosage is carried out in four steps:

[0048] - Preparation of the raw material: this consists of coarse grinding in order to obtain a heterogeneous particle size similar to the grinding carried out in the animal feed industry;

[0049] - Fat extraction: This involves bringing the previously weighed raw material into contact with an extraction solvent (e.g., petroleum ether) under controlled agitation for a predetermined duration, in this case 10 minutes. It is also possible to conduct this extraction phase for different durations, thus allowing for varying fat release kinetics.

[0050] - Solid / liquid separation by filtration: This consists of filtering the ground material dissolved in the solvent in order to recover only the liquid phase in a dry and previously tare flask.

[0051] - Solvent removal from the extract and weighing of the dry residue: This involves evaporating the solvent that dissolved the fat. Once evaporated, dried, and cooled, the flask is weighed. This cycle is repeated until a constant mass is obtained. This is how it is possible to characterize the seeds using the MGD (Grain Mass Deficiency), the values ​​of which depend on the operating conditions.

[0052] This released fat, considered available because it is quickly accessible, will be absorbed through the intestinal wall. Once absorbed, it can be used by the animal for its own metabolism.

[0053] 3. A significant presence of antinutritional factors

[0054] Beyond their low digestibility, flax seeds contain antinutritional factors that can limit their uses. These antinutritional factors are primarily cyanogenic compounds and total fiber, including soluble fiber such as mucilage.

[0055] Their presence results in limitations in incorporation into food and poor technical performance which can be summarized as a real difficulty in the competitiveness of flax seeds compared to other sources of energy and fat, particularly in monogastric species.

[0056] The main antinutritional factors reported are as follows:

[0057] Cyanogenic compounds

[0058] Flaxseed is characterized by its high content of cyanogenic compounds (5 g / kg of seed on average). This content varies, however, depending on soil and climate conditions and flax varieties. Two diglucosides constitute the main forms present in mature flaxseed: linusstatin (2 to 4 g / kg of seed) and neolinustatin (1 to 2 g / kg of seed), derived from two monoglucoside precursors. Under the action of an enzyme present in the seed, as well as in animals and humans, namely β-glucosidase, the cyanogenic compounds release hydrocyanic acid (HCN), which is highly volatile and highly diffusible.

[0059] Ingested hydrogen cyanide diffuses rapidly throughout the body. The cyanide ion it contains is a potent cellular poison that inhibits at least 40 different enzymes, including cytochrome oxidase, which is essential for electron transport in the respiratory chain to form ATP molecules. In other words, HCN has the same effect as a complete lack of oxygen, since it cannot be used. It blocks the respiratory chain and, in high doses, inevitably leads to death.

[0060] Indeed, in animals and humans, although there are defense mechanisms that allow the elimination of HCN produced at low doses through partial elimination of absorbed HCN via the lungs (due to its extreme volatility), a portion of this HCN, which can become significant during higher absorption, is metabolized via several pathways:

[0061] - The main detoxification pathway involves the transformation of HCN into thiocyanates by transulfurase or rhodanese. The thiocyanates produced in the liver, spleen, adrenal glands, pancreas, thyroid, and kidneys are eliminated via urine, saliva, and sweat.

[0062] - Other, more secondary pathways allow its elimination via urine or via the lungs after hydrolysis and oxidation.

[0063] Thus, high consumption of flax seeds in humans (50g / day) revealed an increase in the level of thiocyanates in the urine, although not significant, but coupled with a 3-fold increase in creatinine excretion (P<0.01) indicating renal dysfunction.

[0064] This illustrates the damage that can be caused by consuming undetoxified flax seeds, and also the energy that becomes both limited due to the mechanism of blocking the respiratory chain and necessary for the body to detoxify the diffusion of HCN in the body.

[0065] To date, the method for measuring cyanogenic compounds consists of an indirect method for measuring HCN after the addition of β-glucosidase according to the standardized analysis method EN 16160 of April 2012. It thus expresses the HCN content in mg per kg of seed.

[0066] Mucilages a) Description

[0067] The mucilage in flaxseed is present in the seed coat. It consists of water-soluble, non-starchy polysaccharides.

[0068] Flax seeds contain significant amounts of mucilage, which increases the viscosity of intestinal contents. This mucilage can represent up to approximately 8% of the total weight of the flax seed. Mucilage is characterized by a high water-retention capacity.

[0069] Abundant scientific literature reports that these mucilages can have a detrimental effect on digestive health and the processes involved by the animal during the transit of food, and are explained below.

[0070] It is assumed that increased intestinal viscosity decreases nutrient digestibility by interfering with the diffusion of digestive enzymes to their substrates and with the movement of digestate through the intestinal lumen (Fengler and Marquardt, 1978, Longstaff and McNab, 1991).

[0071] Viscous polysaccharides can also directly complex with digestive enzymes and decrease their activity (Ikeda and Kusano, 1983).

[0072] In addition, with the increased flow of undigested nutrients, microbial activity is stimulated in the lower part of the intestine, which would lead to greater competition with the host animal for nutrients (Bedford, 1995; Choct et al., 1996).

[0073] Among the available nutrients, fat digestibility can be particularly affected, as certain microbial species are capable of deconjugating bile acids and altering micelle formation, thereby reducing fat digestion (Hymetond, 1985). b) Evaluation methods

[0074] Mucilages are complex compounds to quantify, which explains why several methods are described in the literature, leading to significant variability in assay results, and are generally developed in research laboratories. The method described by Elboutachfaiti et al. (2017), which served as a reference, is based on the extraction of total mucilage as described below:

[0075] Water-soluble polysaccharides are extracted from the seeds by shaking them in distilled water. The filtered mucilage is then collected and centrifuged to remove insoluble particles. The supernatant is purified by tangential ultrafiltration against distilled water. Finally, the retentate solution is lyophilized to obtain flaxseed mucilage.

[0076] Given the limited accessibility of this mucilage assay method, due to its high cost and long analysis time, a simpler and faster alternative method involves assessing the water retention capacity of flax seeds. Mucilages possess a strong property of retaining significant amounts of water. This makes it easier to indirectly measure mucilages, or more precisely, the effects of mucilages, which are known for their viscosity.

[0077] The internally developed method for evaluating the water retention capacity (WRC) of flax seeds quantifies the volume of water retained by the seeds in their raw state. This retained water corresponds to the volume of water that does not flow out under the influence of gravity. It therefore represents the total amount of water retained by soluble dietary fibers such as the non-starch polysaccharides in the seed, the value of which depends on the specific operating conditions and has a high affinity for water.

[0078] In short, the determination of water retention capacity is carried out using 10 g of seed(s) (W. MP), previously coarsely ground, which has been saturated with water (80 g of water at room temperature, W. water) for a period of one hour. After this saturation period, the free water in the mixture is allowed to drain for 10 minutes through a sieve (1 mm mesh). This free water is then weighed (W. free water). When the free flow ceases, the seed mixture is said to have reached its water retention capacity (WRC). The WRC (g / g DM) is expressed according to the formula:

[0079] [Water content - Free water content] / MP content, then reduced to the dry matter of the seed, according to the expression below:

[0080] P skin - (Pf - Pi)

[0081] 100 - Humidity n " n

[0082] 100

[0083] The water retention capacity thus quantified provides a predictive criterion for the effect of mucilages which can interfere both in the industrial processing of flax seeds and in the digestion process implemented by animals.

[0084] The fibers

[0085] Monogastric animals, in general, are not well equipped in terms of digesting the fibers present in their diet. Flax seeds are relatively rich in fiber, containing 9.2% crude cellulose and 22.1% NDF (Neutral Detergent Fiber) according to INRA.

[0086] These fibers therefore also represent a category of antinutritional factors that it is important to highlight, particularly in young people.

[0087] monogastric livestock such as chickens, piglets or fish, but also for young domestic animals such as dogs and cats.

[0088] These fibers not only have low digestibility, but also provide less digestibility of proteins and other nutrients, since they act as a barrier to the animals' digestive enzymes by limiting their accessibility, as well as a bulking effect in the intestine limiting the assimilation of nutrients.

[0089] In summary

[0090] While flaxseeds have potential benefits for improving animal and human health parameters, or for enhancing the nutritional quality of livestock products, it has been shown above that this potential is severely limited by:

[0091] - The low digestibility of raw flaxseed and its Omega-3 fatty acids is due to the presence of a complex pectocelluosial cell wall surrounding the flaxseed. These components are therefore poorly accessible and digested by monogastric animals, and are also poorly released and hydrolyzed in the rumen of ruminants. Furthermore, more specifically for monogastric animals, other intrinsic nutritional components of the seed, such as fiber, are poorly utilized.

[0092] - The presence of antinutritional factors such as cyanogenic compounds, mucilage and fiber, which are naturally present in the raw seed as a natural defense mechanism of the seeds against their aggressors.

[0093] - In flaxseed, it is mainly the cyanogenic compounds that are noted, but we can also mention the fibers and more particularly the soluble fibers such as mucilages given their water retention capacity and their high viscosity power impacting the digestive process of young animals.

[0094] The challenge, therefore, is to best express the potential of flaxseed by promoting its nutritional and metabolic value while limiting antinutritional factors. TECHNICAL PROBLEM TO BE SOLVED

[0095] A. The insertion of flax seeds: advantages and limitations

[0096] The use of flax seeds in food is currently present, but relatively underdeveloped due to technical and economic barriers.

[0097] From a technical point of view, the challenge is to reduce antinutritional factors and improve the digestibility values ​​of nutrients (energy, protein, fat, etc.) of the seeds, and thus improve the benefit / risk ratio linked on the one hand to the intake of Omega 3, and on the other hand to that of HCN and other poorly digestible fibers.

[0098] From an economic point of view, because the technical characteristics obtained remain insufficient, the use of flaxseed in animal feed is not developed, and exists only in rare situations where farmers benefit from better results in terms of animal health and / or better prices on the products they sell due to a better nutritional composition.

[0099] The challenge today is therefore to make the use of flaxseed economically viable.

[0100] Among the levers for increasing the use of flaxseed in food, two main avenues exist: plant breeding and, above all, technological processes for seed treatment. i. Varietal selection

[0101] The selection of oilseed flaxseed is based primarily on agronomic criteria, namely yield, earliness, lodging resistance, etc. It is also based on criteria related to the use of the seeds, and to date, the seed quality criteria included in breeding programs are relative:

[0102] - to the oil content of the seed and its extractability, for crushers who will seek to increase the yields of oil separation from the cake, and to another extent;

[0103] - the oil content of the seed and the proportion of Omega-3 in that oil, for companies seeking to increase the Omega-3 content per kg of flaxseed and gain a competitive edge. But until now, varietal selection of oilseed flax has paid little attention to antinutritional factors, to the point of marketing specific varieties with reduced levels of cyanogenic compounds or mucilage. Nor has it focused on making Omega-3 more digestible or bioavailable.

[0104] Thus, it can be considered that the genetic lever has not yet proven its effectiveness in improving the benefit / risk ratio between the quantity of digestible Omega-3 and the quantity of antinutritional factors, except through a higher concentration of oil and Omega-3 in certain varieties. ii. Technological processes

[0105] Alongside varietal selection work, numerous technological processes have been tested to reduce or eliminate antinutritional factors, and improve the nutritional and digestibility values ​​of the seeds.

[0106] The different processes tested so far relate to mechanical, thermal, thermomechanical, or enzymatic approaches.

[0107] It is important to note that the literature on technological processes for treating flax seeds is very heterogeneous, incomplete, informative, and mostly outdated. Many published studies have sought to compare a technology with an untreated control, or to compare technologies two by two, relying on often different in vitro evaluation techniques and / or in vivo studies under varying conditions.

[0108] Furthermore, the partial results described in the literature are outdated and do not incorporate technological advancements over the past 30 years. They also only present comparisons between technologies, without considering the optimization of these technologies or, even better, combinations of technologies.

[0109] Therefore, the current bibliography is usable to a certain extent but does not allow us to draw clear conclusions about the technologies and corresponding parameters to be used, particularly for the purpose of industrial implementation.

[0110] On the other hand, in vivo studies, which are generally quite old, have largely been conducted on animals with less productive genetics and on feeds less suited to current food systems. Indeed, animal genetic selection, which improves feed conversion ratios by an average of 2.5% per year, is carried out for global production, using conventionally used corn and soy-based feeds.

[0111] This does not allow for optimal use of more diverse raw materials as sources of energy and fats, such as flax seeds.

[0112] This is why the effects of FANs and technologies are likely to be amplified by current in vivo evaluation models. Because in this context, it is becoming increasingly difficult to improve the performance of current flax seeds.

[0113] It is in this sense that, although many technological treatments have been tested in the past, some of them deserve to be re-examined in the current technical and economic contexts.

[0114] The main treatments tested so far on these flax seeds are as follows:

[0115] 1. Mechanical treatments

[0116] Conventional mechanical treatments (grinding, micronization) destroy the initial structure of the seeds by breaking down the cell walls. These treatments allow division into smaller particles by coarse grinding (5 mm particles) or fine grinding (2-3 cm screen), i.e. by crushing, bursting (hammer mill) or shearing (knife or roller mill).

[0117] The size of the resulting particles and the extent of damage determine the degree of exposure of the biochemical constituents to digestive agents (rumen microbes or intestinal enzymes) and therefore the rate of their digestion. Tissue structure is largely preserved. However, grinding through a 3 mm or even 1 mm screen, followed by agglomeration, destroys tissue structure.

[0118] While the digestibility of flaxseed can be improved by these mechanical treatments, there is no impact on antinutritional factors.

[0119] Another mechanical treatment involves dehulling the flaxseed. Dehulling the seed removes the outer layers, which contain exclusively cellulose, fiber, and certain antinutritional factors such as mucilage, while concentrating certain nutrients like fat, Omega-3 fatty acids, and proteins.

[0120] However, few flaxseed hulling processes have been developed, due to technical difficulties in industrialization and economic profitability.

[0121] 2. Heat treatments

[0122] Among the heat treatments, we find granulation, toasting, flaking, and autoclaving. The action of heat is combined with that of external hydration in the form of water or steam at reduced pressure (moist and prolonged cooking at moderate temperature), with toasting and autoclaving having a greater effect than flaking and granulation.

[0123] These processes can have a positive effect on reducing HCN levels, but only under certain conditions. They have little effect on the energy value of the seed, in particular, and do not mitigate the negative impact of fiber. This explains why they are not widely used in animal nutrition due to a lack of profitability.

[0124] 3. Thermomechanical treatments

[0125] Among the thermomechanical treatments applied to flaxseed, two in particular stand out: crushing and cooking-extrusion.

[0126] The crushing of oilseeds is the first step in the process of obtaining edible oils, the second step being refining. The crushing of flaxseed is generally carried out in order to separate, by cold pressing, on the one hand, linseed oil intended primarily for the paint market (and for the rare food applications due to its high oxidizability) and, on the other hand, linseed meal intended for the animal feed market, like all oilseed meals.

[0127] It is generally accepted that linseed meal does not undergo solvent extraction to remove residual oil after the cold-pressing stage. Thus, this meal still contains approximately 13% fat, which has the same proportion of Omega-3 fatty acids as the fat in the seeds. However, the major drawback of this process is that, on the one hand, the meal intended for food use is highly concentrated in cyanogenic compounds, without making the Omega-3s easily digestible.

[0128] On the other hand, the oil, which in some cases can be used for food, no longer contains the hydrophilic antioxidants of the seed, making it highly oxidizable, especially since Omega-3 fatty acids are highly unsaturated and therefore highly reactive to oxidation. This is precisely why flaxseed oil has been subject to drastic limitations on its use, even for partial use in human food.

[0129] Extrusion cooking, on the other hand, is a complex operation equivalent to several unit operations: mixing, cooking, and shaping. Each of these operations can be modulated, depending on the material to be processed and the product to be obtained, by appropriately selecting the machine's control parameters. Driven by the augers, the material is subjected for a very short time (20 to 60 seconds) to high temperatures (100 to 200°C), high pressures (50 to 150 bar), and varying degrees of shear. Under the influence of these physical parameters, the material undergoes physicochemical changes and homogenization. Its exit through the die gives it its final shape. The sudden drop in pressure during extrusion triggers the instantaneous vaporization of any water present, which can lead to a characteristic expansion of the product.

[0130] The first cooker-extruders were single-screw. Second-generation equipment consists of twin-screw devices (comprising two parallel, tangent or co-penetrating screws, rotating in the same or opposite directions); they are more flexible in use and allow, in particular, for more consistent operation.

[0131] This process, as evidenced by European patent no. 1,155,626, can, under certain conditions, allow the detoxification of part of the hydrocyanic acid and can improve the digestibility of seeds, but the results remain variable and not always reproducible if the many parameters involved are not controlled: type of machine (single screw / twin screw), mechanical constraints (type of screw, airlock, speed, die...), thermal constraints (water, steam, duration...), presentation constraints (die for flours, croquettes...).

[0132] Thermomechanical processes are increasingly being developed for this type of application, but they must be thoroughly mastered to fully exploit their potential. 4. Enzymatic Treatments

[0133] All animals secrete enzymes to digest food. However, the animal's digestive process is not 100% efficient. For example, pigs and poultry do not digest 15 to 25% of the food they ingest. Adding exogenous enzymes to animal feed, particularly for monogastric animals, improves the digestibility of starches, proteins, fiber, and minerals. This enzyme supplementation leads to better growth performance and reduced waste released into the environment.

[0134] Enzyme supplementation is carried out using an isolated commercial enzyme, selected for a few specific enzymatic activities. Regarding flaxseed specifically, few trials have sought to demonstrate the benefits of this technique as a means of improving the nutritional value of flaxseed, likely because this seed will remain at low levels of incorporation in feed despite its unique fiber content. Therefore, this enzymatic approach has not yet proven to be technically effective and economically viable. 5. Treatments applied by economic actors in the livestock sector

[0135] The observation, in today's livestock sectors, is based on the fact that:

[0136] 1 - the varieties produced generally do not have specific characteristics in terms of composition beyond oil and Omega 3 content, except for agronomic characteristics;

[0137] 2- The technological processes for using seeds in livestock farming are either basic, since they rely solely on mechanical treatments such as grinding and crushing for use in the form of oil and cakes, or on thermal granulation treatments, or partially elaborate, since they rely on thermomechanical cooking-extrusion treatments for the purpose of partial detoxification, essentially.

[0138] Indeed, current uses rely either on ground, granulated, or extruded seeds, or on oil. However, given the limitations outlined above for each of these processing methods, the use of flaxseed in food remains underdeveloped, primarily due to a lack of technical and economic viability, despite the health benefits of Omega-3 fatty acids. iii. In summary

[0139] Some technical advantages can be achieved through genetic engineering, such as the concentration of Omega-3 fatty acids in seeds. Other advantages can be gained through seed selection, such as the elimination of certain antinutritional factors like cyanogenic compounds and mucilage. Still others can be achieved through processing methods, such as dehulling, which removes the mucilage from the seed coat, or thermal processes that eliminate HCN (hydroxycitric acid).

[0140] Finally, mechanical processes such as grinding contribute to improving the nutritional value of seeds, as do thermal processes such as toasting and granulation, and / or thermomechanical processes such as trituration or extrusion cooking.

[0141] Separately, each of these approaches – genetic selection, seed selection, or technological processes reported in the bibliography – offers well-known areas for improvement in limiting or eliminating antinutritional factors on the one hand and / or improving the digestibility / degradability values ​​of seeds on the other, but none of them is sufficient to be technically complete and economically unbeatable in terms of technical and economic value for animals.

[0142] In a historical market where the choice of plant sources of energy and / or lipids present in the diets of animals and humans is based on essentially economic criteria, the place of flax seeds in view of existing limits has been reduced to nothing, or to the rare exceptions of their nutritional advantages, in favor mainly of carbohydrate energy sources such as cereals, and lipid sources such as palm, soybean, rapeseed, coconut, sunflower oils, etc., rapeseed, soybean seeds, etc.

[0143] In a new market where the trend is not only to produce meat or eggs at a competitive price, but also to meet consumer expectations, the challenge now becomes having competitive sources of energy and lipids, as well as sources of digestible, traceable, secure, and locally produced essential fatty acids. B. A favorable but insufficient context

[0144] To successfully reintroduce flax seeds into soils, troughs and bowls, and plates in a sustainable way, there are favorable contextual elements such as "political" incentives ("Ecophyto" plan, "EcoAntibio" plan, etc.), agronomic advantages (yield of subsequent cereals, less use of inputs...), potential responses to many agricultural expectations (soil and animal health, added value of production, economic sustainability...) and societal expectations (healthy nutrition, local, biodiversity, environment...).

[0145] However, this favorable environment is not enough to strengthen the use of flax seeds if the production systems for plants and animals are not technically robust and economically viable.

[0146] This must be accompanied by the development of the most efficient, safest and most robust technologies at the technical and economic level, in order to provide the best solutions for the agricultural and livestock sectors, and for other uses such as for domestic animals, or even directly for humans.

[0147] In summary, a particular interest lies in improving the ratio of the amount of digestible (or available) Omega 3 to the amount of residual NAF, or vice versa, regardless of the individual who consumes these flax seeds.

[0148] The present invention therefore aims to achieve this objective.

[0149] SUMMARY OF THE INVENTION Thus, the present invention relates to a process for treating flax seeds (Linum usitatissimum) in order to improve their value as food, particularly for animals, characterized in that it comprises the following successive steps:

[0150] a) Use of flax seeds provided that these seeds have: - a fat and / or Omega 3 fatty acid content higher than the values ​​indicated in the table below:

[0151]

[0152] (ATG = total fatty acids)

[0153] and, only when said seeds are intended for feeding monogastric species, a value in water retention capacity or mucilage content, as well as a crude cellulose and / or neutral detergent fiber (NDF) content, these values / contents being lower than those indicated in the table below:

[0154]

[0155] And with a hydrocyanic acid content of less than 250 mg per kilogram of raw material.

[0156] b) Mixing, provided that there are at least two raw materials of different nature and / or quality, then fractionation, or fractionation and then mixing, of said seeds from step a) until the seed coats and kernels of said seeds break;

[0157] c) Implementation of a thermal preparation step for the seeds from step b) with steam and / or a water-based liquid, until a temperature between 30 and 90°C and a humidity greater than 10%, preferably 15%, is obtained, the duration of this preparation being greater than 2 minutes, preferably 15 minutes;

[0158] d) Applying a minimum pressure of 10 bar to the seeds or mixture from step c), for a period of more than 10 seconds, until a temperature above 80°C is reached, preferably between 100 and 150°C;

[0159] and / or d bis) Heating the seeds or mixture from step d), respectively from step c), for a minimum of 15 minutes, preferably from 30 minutes to 2 hours, at a temperature above 80°C, preferably 90 and 150°C.

[0160] According to other non-limiting and advantageous features of the invention:

[0161] - the thermal step c) of preparation is carried out in the presence of at least one exogenous enzyme identified from among the following families: arabinofuranosidases, beta-glucanases, cellulases, glucoamylases, pectinases, pectin methyl esterases, phytases, proteases, xylanases and, preferably, xylanases, beta-glucanases and pectinases, said exogenous enzyme having previously been added to the seeds or mixture. ;

[0162] - at the thermal step c) of preparation in the presence of exogenous enzyme, we place ourselves at a humidity greater than 15%, preferably 25%, and we make the preparation last for at least 15 minutes, preferably 60 minutes;

[0163] - during the implementation of said thermal preparation step, the mixture is stirred;

[0164] - when mixing and then fractionating, a new mixing is carried out after said fractionation;

[0165] - said fractionation is continued until at least 90% of the seeds have a particle size of less than 2000 micrometers, preferably less than 1500 micrometers;

[0166] - the implementation of step d), or d bis), is interrupted when the HCN content of said seeds is lower than that indicated in the table below and the MGD content is higher than that indicated in the table below:

[0167]

[0168] - following step a), or upstream, the seeds are sorted according to a criterion chosen from among size, weight, shape, density, an aerodynamic, colorimetric or electrostatic parameter;

[0169] - following step a), the seeds are dehulled and one or the other of the fractions is used, preferably when the dehulling is characterized by a concentration of at least 3% of fat in the so-called almond fraction, preferably at least 5%;

[0170] - following step a) or b), the seeds, whole or hulled, are crushed, and the cake is used, preferably when it contains at least 8% fat;

[0171] - at least one other raw material chosen from the group consisting of protein seeds, cereals, cereal and protein seed co-products, sources of simple and complex carbohydrates, oilseed cakes and other oilseed co-products is mixed with said flax seeds;

[0172] - during the implementation of at least one of the said steps, at least one antioxidant substance is added to the said seeds;

[0173] - it includes a step, after the implementation of step d), respectively d bis), during which said seeds are cooled;

[0174] - finally, the said seeds are packaged, transported and stored away from light;

[0175] - the said seeds are finally conditioned under at least partial vacuum, or by at least partial replacement of the air with an inert gas.

[0176] DETAILED DESCRIPTION OF THE INVENTION

[0177] The process that is the subject of the present invention consists of a combination of steps:

[0178] Step a): Use of specific seeds

[0179] Use of flax seeds (Linum Usitatissimum)

[0180] High in at least one nutritional component, including fat and / or Omega 3. Seeds with levels exceeding the thresholds below are considered selected or chosen for their high fat and / or Omega 3 content:

[0181] Preferably, high-content seeds contain at least 40% MG, or even 42%; and 56% ALA in total FA, or even 58%.

[0182] Selecting flaxseed based on its nutritional quality has an impact on the subsequent processing steps. The criteria used here for selecting flaxseed are its Omega-3 content in the form of alpha-linolenic acid (ALA) and its fat content.

[0183] The choice of using flax seeds rich in one or both of these criteria leads to an impact on the following steps, resulting in increased digestibility and / or detoxification, as described below.

[0184] This is illustrated below by the example of a seed or the formulation of a mixture made from flax seeds where the ALA content is fixed at 205g / kg:

[0185] - Selection of flax seeds based on ALA content

[0186] The higher the ALA content in flaxseed, the less ALA is needed to prepare the 205g ALA mixture. This lower incorporation leads to a lower level of fat content. In the thermomechanical process, a lower fat content results in greater mechanical resistance of the seed being processed. This leads to increased digestibility, reflected in the increased available fat (AF), explained by greater mechanical forces resulting in higher pressure and temperature. These forces promote the rupture of cell walls and plasma membranes, leading to a greater release of fat from the lipid vacuoles. Therefore, the higher the ALA content of the flaxseed, the greater the AF of the processed flaxseed, and consequently, the more digestible it will be for animals.

[0187] - Selection of flax seeds by fat content

[0188] The fat content of the seed significantly influences its total ALA content. Therefore, the higher the fat content, and for the same target of 205g, the less flaxseed is needed. This reduced incorporation significantly decreases the mucilage content of the seeds. As previously described, a lower mucilage content results in increased nutrient digestibility by the enzymes present (substrate accessibility, enzyme diffusion, mechanical resistance). Thus, the higher the fat content of the flaxseed, the better the enzyme efficiency is preserved.

[0189] And, only when said seeds are intended for feeding monogastric species, with a low water-holding capacity or low levels of two poorly utilized nutritional components, namely neutral detergent fiber (NDF) and mucilage. Seeds with levels and / or values ​​below the thresholds below are considered selected or retained seeds with a low water-holding capacity or low levels of poorly utilized nutritional components:

[0190]

[0191] Preferably, low-content seeds contain at most 19% NDF, or even 17%; 4g / kg of mucilage, or even 3.5% or 4g of water retention per g of DM, or even 3.5.

[0192] Besides the detrimental impact soluble fibers have on animal digestive processes, they can also disrupt the technological processes used to increase seed digestibility—such as available fat—and to reduce, or even eliminate, their levels of antinutritional factors. Similar modes of action are explained below: The impact of these soluble fibers is multifaceted and characterized by an increase in viscosity due to the strong affinity between soluble fibers and water. This leads, on the one hand, to reduced substrate accessibility (acting as a barrier) and impaired enzyme diffusion; and on the other hand, to increased mechanical resistance, limiting the diffusion of heat and water, as well as enzyme / substrate contact.The soluble fibers of flax seeds are particularly characterized by their mucilage content, and their hydrophilic properties are assessed by their water retention capacity (WRC).

[0193] And a hydrocyanic acid content of less than 250 mg per kilogram of raw material;

[0194] Step b): Mixing and splitting the seeds

[0195] Choice of at least one mechanical mixing technology, provided that there are at least two raw materials of different nature (i.e., at least one of which is not made of flax) and / or of different quality, and of a mechanical seed fractionation technology parameterized in such a way that they allow, for the first, to produce a homogeneous mixture of flax seeds and any additional raw materials, and for the second, to break the seed coats and kernels in order to make the nutrients more accessible to enzymes (endogenous or exogenous and digestive) and, thus, improve the digestibility and detoxification of the seeds.

[0196] One preference is to pre-mix the materials before fractionating them, but it is also possible to first operate by separately fractionating the materials and then mixing them, but also to carry out two mixing operations, one before fractionation, the other after.

[0197] The simple and / or combined mechanical stresses implemented to fulfill these functions can be obtained in particular by impact, cutting, compression, shear or abrasion.

[0198] Seed fractionation is characterized by particle size analysis, which determines the size of the particles produced by the process. The maximum particle size of 90% of the particles produced by this mechanical technology is preferably less than 2000 µm and even more preferably less than 1500 µm. This size can be achieved, for example, with a horizontal hammer mill using the parameters below, for equipment with a capacity of 10 t / h and a 200 kW motor, a rotation speed of 2800 rpm, and a screen size of 3 mm. This size can also be achieved with other common equipment such as hammer and roller mills or crushers, and paddle mills.

[0199] Finally, other technologies exist and can also fulfill this function: grinding wheel, disc mill, pin mill, cutting head mill, ball mill, blade mill or crusher, impactor or impact crusher, etc.

[0200] Step c: Preparatory heat treatment

[0201] This step consists of choosing at least one thermal technology parameterized in such a way that it meets the following characteristics:

[0202] A. First possibility: Hydrothermal preparation stage

[0203] This step has the dual objective of initiating the detoxification of flax seeds by triggering the activation of endogenous enzymes and facilitating the following thermal step by improving thermal conduction capabilities.

[0204] This step involves impregnating the seeds with water vapor and / or a liquid with water, in order to achieve on the previously fractionated seeds a temperature between 30 and 90°C for a period of more than 2 minutes and a humidity greater than 10%.

[0205] Preferably, the seeds should be soaked for a period of more than 5 minutes, or 15 minutes or even 30 minutes, and preferably less than 4 hours, or even 8 hours, without exceeding 24 hours for a humidity greater than 12%, or even 15%, and preferably less than 40%, without exceeding 60%.

[0206] And very advantageously, it is advisable to soak the seeds for a period of more than 1 hour, or even 2 hours, for a humidity greater than 18%, or even 20% or 25%.

[0207] Water can be added during this step and / or during the mixing step.

[0208] Hydrogen cyanide is the product of the degradation of cyanogenic compounds (linamarin, linustatin, neolinustatin) by beta-glucosidase. The temperature, duration, and humidity conditions mentioned above allow for efficient enzymatic action. It should also be noted that soluble fibers increase viscosity due to the strong affinity between mucilage and water, and can thus limit the efficiency of this enzymatic process (substrate accessibility, enzyme diffusion, mechanical resistance). Below 30°C, the enzymes are inactive or only slightly active, and above 90°C, most of them are deactivated by heat, and even above 60°C.

[0209] The equipment capable of performing this step includes, but is not limited to: a preparer, a pre-conditioner and conditioner, a cooker, a mixer, a toaster, a steam impregnator, a ripener.

[0210] B. Second possibility: Hydrothermal and enzymatic preparation stage

[0211] This preparation step consists of applying the same preparation conditions as described in the first possibility section. It differs simply in that at least one exogenous enzyme, not present in flax seeds, is activated, which can be provided in particular as a processing aid (enzyme extract, etc.), from additives, raw or fermented raw materials, etc., and added to the process at one of the preceding steps, or during this step.

[0212] The temperature characteristics are then chosen so that they correspond to the activity ranges of the selected enzymes, but remain between 30 and 90°C. The required duration and humidity characteristics are the same as those described above, considering however that these exogenous enzymes require more favorable conditions than endogenous enzymes, because they are not spatially and temporally as close to their substrates.

[0213] It is in this sense that the impregnation conditions should be adapted, so that the impregnation lasts at least 15 minutes, preferably 60 minutes, and preferably less than 4 hours, or even 8 hours, without exceeding 24 hours for a humidity greater than 15%, preferably 25%, and less than preferably 40%, without exceeding 60%.

[0214] The enzyme (or enzymes) to be introduced belongs (or belong) to the families of arabinofuranosidase, beta-glucanases, cellulases, glucoamylase, pectinases, pectin methyl esterase, phytase, proteases, xylanases, galactosidases, and preferentially, to xylanases, beta-glucanases and pectinases.

[0215] It (or they) will have been previously chosen for its efficiency in hydrolyzing specific chemical bonds that the animal is unable to form at all, not completely, or not quickly enough. The aim will be, in particular, to break down carbohydrates that are not hydrolyzed or are poorly hydrolyzed in the animal to allow better accessibility of the other constituents of the seed by digestive enzymes, which accessibility can be explained, among other things, by the dissociation of carbohydrates from nutritional or antinutritional compounds.

[0216] Examples of equipment capable of performing this step include: a preparer, a pre-conditioner and conditioner, a cooker, a mixer, a toaster, a steam impregnator, a ripener, a reactor.

[0217] Step d / d bis: Heat treatment

[0218] This heat treatment step is carried out with and / or without pressure.

[0219] A. Heat treatment stage under pressure

[0220] This step consists of putting the seeds, or the mixture thus prepared, under a minimum pressure of 10 bars, preferably greater than 20 bars, for a time greater than 10 seconds, preferably between 10 seconds and 2 minutes, at a temperature greater than 80°C, preferably greater than 100°C, or even between 100 and 150°C, and even more advantageously between 110 and 140°C (and never exceeding 160°C).

[0221] This temperature is advantageously achieved by self-heating due to shear, friction and compression forces and possibly additionally by an exogenous thermal input, by conduction (heat transfer fluid, electrical resistance, electromagnetic fields, etc.) or by adding steam.

[0222] Indeed, the increase in pressure exerted on the previously fractionated and prepared flax seeds, which also leads to an increase in temperature, will allow on the one hand better evaporation of the HCN released thanks to a sudden change in pressure, or in other words, thanks to an isothermal expansion, and on the other hand an improvement in the digestibility of the seeds, and in particular of Omega 3 thanks to the rupture of the cell walls thus facilitating the availability and therefore the accessibility of the lipids of the seeds.

[0223] Also, this step has the effect of inhibiting enzymatic activities due to the induced temperature.

[0224] A non-exhaustive list of pressure heat treatment equipment capable of performing this step is as follows: extruder, cooker-extruder, expander, press.

[0225] The aim of this step is to reduce antinutritional factors and improve the digestibility of energy and / or protein, while deactivating endogenous and / or exogenous enzymes.

[0226] B. Heat treatment stage without pressure

[0227] This step consists of a heat treatment without pressure, the duration of which is then extended so that it is greater than 15 minutes, preferably 30 minutes, or even between 30 minutes and 2 hours, and the temperature is greater than 80°C, preferably greater than 90°C, or even between 90 and 150°C.

[0228] This temperature is made possible by an exogenous heat input, by conduction (heat transfer fluid, electrical resistance, electromagnetic field, etc.) or by the addition of steam, for example.

[0229] The aim of this step is to inhibit enzymatic activity and evaporate the released HCN. Since evaporation is less rapid here, it is necessary to increase the exposure time of the material to a sufficiently high temperature to allow the hydrogen cyanide to change state from liquid to gas.

[0230] Similarly, suitable equipment for this pressureless heat treatment includes, for example, the dryer, the toaster, the thermostatically controlled screw, etc.

[0231] This step also aims to deactivate endogenous and / or exogenous enzymes, while improving fat availability, particularly in the case of heat treatment under pressure. Finally, it allows, where necessary, for a reduction in the mixture's moisture content, which should not exceed 14%, preferably 12%, to ensure good preservation of the mixture. One way to characterize the effectiveness of this step (or these steps) is to evaluate the reduction of hydrocyanic acid (HCN) and the improvement in available fat (AF).

[0232] Thus, the HCN value is expected to be less than 30 mg / kg, preferably 20 mg, or even 10 mg. And regarding MGD, it is expected to be at least greater than 65%, preferably 70%, or even 75%, and even 80%.

[0233] The previous steps of the process, as described above, can also be advantageously implemented by taking into account the elements described below:

[0234] Cooling

[0235] At the end of the previous step, the processed seeds are hot. They then need to be cooled to a temperature that will ensure their stability over time, allowing them to be preserved and stored in good conditions until consumption. For example, the temperature should not exceed 30°C above ambient temperature, preferably 20°C. Sorting

[0236] This sorting stage allows seeds to be grouped according to criteria such as size, weight, shape, density, or aerodynamic, colorimetric, and electrostatic characteristics. The tools used to perform these operations include: sifters, separator cleaners, bolters, destoners, plansifters, density tables, winnowing machines, optical sorters, and aeration systems (air columns, suction, blowers, etc.), including magnetic systems.

[0237] This operation may aim to separate seeds of different species, remove impurities, allot seeds of identical species, etc.

[0238] Peeling

[0239] The dehulling step aims to concentrate the protein, energy (in the form of lipids), and fiber content. This process results in the production of several fractions, including a kernel and a husk. This operation allows for meeting the nutritional needs of different species by limiting the proportion of poorly digestible components and reducing the concentration of certain antinutritional factors, particularly in the kernel fraction. The husk fraction, on the other hand, is more concentrated in fiber, mucilage, and lignans, and more diluted in fats, Omega-3 fatty acids, and proteins.Thus, using the kernel fraction rather than the whole seed allows for a reduction in the proportion of soluble fiber for the same amount of Omega-3, which leads to improved efficiency of enzymatic mechanisms (substrate accessibility, enzyme diffusion, mechanical resistance). As for cyanogenic compounds, they are particularly present in the kernel, but not very diluted in the skins.

[0240] This peeling step is characterized by a minimum yield assessed from the effect of concentration or dilution of at least one of the following constituents with regard to the fraction most concentrated in almond:

[0241] - Fat content: +3%, then 5%, then 10%

[0242] - Crude protein +3%, then 5%, then 10%

[0243] - Crude cellulose -5%, then -10%, then -15% - Mucilage -20%, then -30%, then -40%

[0244] - Lignans -20%, then -30%, then -40%

[0245] Peeling is achieved through the combination of a phase of mechanical stresses and a separation phase, following, where appropriate, a possible rehydration of the almond preceded by a thermal pretreatment phase facilitating peeling.

[0246] The simple and / or combined mechanical stresses used to perform these functions can be impact, compression, or abrasion. The tools used to carry out this phase include, but are not limited to: roller and hammer crushers, impact crushers, polishers, paddle mills, grinding wheels, disc mills, pin mills, cutting head mills, ball mills, blade crushers, etc.

[0247] Separation can be carried out according to criteria such as size, weight, shape, density, or aerodynamic, colorimetric, or electrostatic characteristics. Tools used for this process include: sifters, separator cleaners, bolters, destoners, plansifters, density tables, winnowing machines, optical sorters, aeration systems (air columns, suction, blowers, etc.), and magnetic separators, among others.

[0248] At the end of this step, it is therefore necessary to specify that the following steps of fractionation (if needed), thermal preparation (if needed) and heat treatment as described are carried out on co-products of flax seeds, and not on whole flax seeds.

[0249] Seed crushing and linseed cake processing

[0250] Alternatively, after step a) or b) described above, the whole or hulled flax seeds can be crushed to obtain linseed oil and linseed meal. Since the linseed meal still has a fat content above 8%, preferably 10% or even 12%, it still contains a certain amount of Omega-3 fatty acids, but above all, a large amount of HCN (hydroxycitric acid).

[0251] As with the previous dehulling stage, it is important to clarify that following this crushing stage, the subsequent fractionation, heat preparation (if necessary), and heat treatment stages, as described, are carried out on the linseed meal, a co-product of flaxseed crushing, and not on whole flaxseeds. Use of additional raw material(s)

[0252] It becomes advantageous to choose at least one raw material to add to the flax seeds, a raw material selected for its technological, nutritional, and / or economic properties. Indeed, depending on the intended use of the mixture produced by the process, and its destination in terms of animal species and physiological stage, the choice of the raw material(s) will focus particularly on the nutritional characteristics and the cost of the raw materials.

[0253] But they will also have to be chosen based on their technological interests, in particular through:

[0254] - their physical properties and therefore their predispositions to make the constraints of the process more advantageous, thus modifying the pressure forces and the thermal energy, considering in particular their rheological behavior during the process;

[0255] - their ability to mix with flax seeds in humid conditions and therefore their ability to adsorb (surface capture) or absorb (capture by assimilation) oil and / or water;

[0256] - the presence and / or abundance of enzymes of interest, endogenous to the additional raw material, and therefore their ability to accentuate the enzymatic activities of the process, via for example beta-glucosidase to improve the detoxification of flax seeds.

[0257] Advantageously, flax seeds will be preferentially combined with a portion of protein seeds and / or cereals, especially when the thermal technology involves a heat treatment step under pressure.

[0258] Indeed, to constrain the passage through the extruder, the addition of protein crops and / or cereals allows the flax seeds to be technologically better processed and to increase the bioavailability of the fat.

[0259] Finally, more generally, the choice of additional raw material is based preferentially on the potential for nutritional and economic improvement that can be achieved by applying the said process to flax seeds.

[0260] Thus, among the additional raw materials, preference will be given first to protein seeds and cereals, then to cereal and protein co-products, to sources of simple or even complex carbohydrates, and to oilseed cakes and other oilseed co-products, then to all other usual raw materials in animal nutrition.

[0261] Use of an antioxidant solution

[0262] It may be prudent, in order to preserve the nutritional and functional integrity of the Omega 3 of the flaxseed produced by the process, to add a step acting as an antioxidant solution.

[0263] Flaxseed naturally contains antioxidants in the form of lignans, a family of phytoestrogens. Nevertheless, it is recommended, if necessary, to add an antioxidant solution, particularly when transport and storage conditions and durations are demanding. Temperature, light, and ventilation are all factors, though not an exhaustive list, that increase the risk of fatty acid oxidation, and these can be technically and economically challenging to control.

[0264] The proposed antioxidant solution consists of using at least one of the following solutions:

[0265] - Packaging, transport and storage of seeds from the invention protected from light; for example in bags, "big bags" and other opaque containers;

[0266] - Packaging within a bag in which the oxygen from the air has been removed, at least in large part (vacuum packaging); or replaced by an inert gas, for example nitrogen (inerting packaging);

[0267] - Addition of at least one antioxidant, preferably several, so that they act in a complementary manner at the different stages of the oxidation process, from initiation to propagation, whether they are lipophilic or hydrophilic in nature and of chemical and / or natural origin. This antioxidant input will preferably be made before the fractionation and mixing stage, in powder and / or liquid form.

[0268] To name just a few, some antioxidants of natural or synthetic origin:

[0269] - Phenolic compounds in various forms: simple phenols, flavonoids, isoflavonoids and anthocyanins, phenolic acids and coumarins, lignans, lignins, stilbenoids, non-phenolic metabolites, naphthoquinones, tannins, resveratrol, procyanidins, rosmarinic acid, terpenoid compounds, lecithins...

[0270] - Vitamins such as ascorbic acid and its salts (vitamin C), tocopherols (vitamin E); beta-carotene (provitamin A) and other carotenoids, tocotrienols...

[0271] - Propyl gallate, citric acid, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), tertiary butylhydroquinone (BHQT)...

[0272] Agitation during the preparatory thermal stage

[0273] In step c), one advantage is to agitate the seeds, or the mixture, so that it undergoes the same treatment conditions. Indeed, agitation will allow: - homogenization of the fractionated seeds with the addition of water and any other additional additions, in particular to facilitate the functionality of the antioxidant function on fatty acids as soon as the enzymes come into contact with their substrates;

[0274] - homogenize the added water and the temperature within the seeds or mixture;

[0275] - avoid the formation of agglomerates and thus facilitate the transport conditions of the seeds or mixture.

[0276] The present process makes it possible to achieve advantageous technical results in light of the state of the art.

[0277] Indeed, no process described in the literature achieves the technical and economic improvements obtained by the present process, particularly in light of recent animal production systems characterized by significant genetic advances adapted to a feeding system based primarily on soybeans, corn, and cereals. The combination of the various steps described above yields a flaxseed characterized as being both:

[0278] 1) High in at least one nutritional component

[0279]

[0280] Preferably, the seeds from the invention contain at least 40% MG, or even 42%; and 56% ALA in the total FA, or even 58%.

[0281] 2) Low in at least one nutritional component with low valorization or with a low water retention capacity:

[0282] Preferably, the seeds from the invention contain at most 19% NDF or even 17%; and 4g / kg of mucilage, or even 3.5.

[0283] 3) Low in hydrocyanic acid

[0284]

[0285] Preferably, the seeds from the invention contain at most 20mg, or even 10mg of HCN per kg.

[0286] 4) At an improved level of fat availability, and / or energy digestibility and / or protein and its amino acids:

[0287] Preferably, the seeds from the invention will have an available fat content of at least 70%, or even 75% and up to 80%, under the operating conditions used, after 10 minutes of extraction.

[0288] The results presented above are comparable to those of a seed that has undergone only a fractionation step similar to that described in the invention and a granulation step at a temperature below 100°C. These results are also derived from current animal genetics, considering breeds selected for their productivity. The results presented below highlight the synergistic effect on the energy digestibility of flaxseed from combining flaxseed selection and its technological processing according to the methods specified in the invention.

[0289]

[0290] Base 100 = unselected and untreated flaxseed as described in the table above

[0291] Nutritional value in poultry is assessed through two parameters: energy digestibility or metabolizable energy (ME); protein digestibility (CUD N).

[0292] Regarding energy digestibility, when the factors are considered in isolation, the impact of flaxseed selection results in a 49% increase in its value; the impact of technological processing results in a 10% increase. When both factors are considered, the impact is 103% compared to unselected and untreated flaxseed as described by the invention. Therefore, this is not simply the sum of the effects of selection (+49%) and technological processing (+10%), but a true synergy (=103%).

[0293] From these different characteristics, we can also observe that the present invention makes it possible to improve the detoxification and nutritional value of flaxseed in view of the bibliography and in particular the aforementioned European patent.

[0294] In terms of gross detoxification, the present invention improves the residual content of cyanogenic compounds insofar as the measured HCN reaches 30mg per kg of raw seed, compared to 50mg according to patent EP 1 155 626.

[0295] Given that the invention is preferably capable of reducing the HCN content below the threshold of 20mg / kg or even 10mg / kg.

[0296] In terms of benefit-risk analysis, it is also interesting to compare the amount of HCN per kg of Omega 3 provided.

[0297] The present invention makes it possible to reduce the level of HCN compared to patent EP 1 155 626, going from 160mg to 145mg / kg of Omega 3.

[0298]

[0299] Given that the invention can preferably achieve 100 or even 50 mg of HCN per kg of Omega 3.

[0300] Finally, another way to demonstrate the advantage of the invention is to compare the HCN content per kg of available Omega-3, using the MGD criterion as a predictor of fat digestibility. This demonstrates that the present invention provides a better efficiency ratio compared to the aforementioned patent.

[0301]

[0302] Given that the invention can preferentially achieve 145 or even 65 mg of HCN per kg of available omega 3.

[0303] But the present invention also goes beyond simply improving the benefit / risk ratio by proposing the use of seeds that are inherently more digestible due to their lower content of less valuable compounds. The table below presents a comparison between raw seeds and seeds produced according to the invention, showing the quantities of NDF and mucilage in grams per kilogram of raw product, as well as in grams per kilogram of Omega-3 and, most importantly, in grams per kilogram of available Omega-3.

[0304] Thus, we demonstrate the double advantage of a seed with fewer low-value compounds on the one hand and more available Omega 3 on the other.

[0305] These results characteristic of the seeds from the invention are synergistic insofar as hydrocyanic acid is not involved in the so-called digestibility results, nor in the availability of fat which is shown to be well correlated with the digestibility results.

[0306] Indeed, HCN has a negative effect on the animal's energy metabolism. It inhibits the enzymatic activity of cytochrome oxidase, which is responsible for electron transport in the respiratory chain to form ATP molecules.

[0307] Thus, the invention has the advantage of not only achieving high levels of so-called MGD (Gross Fatty Acid Distillation) and digestibility of flaxseed, high levels of nutritional components and low levels of components with low valorization, but also avoiding technical underperformance and other health problems related to the potential emission of HCN (hydroxychloroquine). 0) Digestibility test on broiler chickens

[0308] In an experimental farm, the digestibility of flaxseed produced using different processing methods was evaluated. Digestibility trials were conducted on male chickens (ROSS PM3) by substituting 30% of the base feed with the seeds being tested. Energy utilization and protein digestibility were calculated by difference, taking into account the principle of additivity. The factors tested were, both individually and cumulatively, the impact of flaxseed selection and its processing as described in the invention. The table below presents the following: Characteristics of the selected flaxseeds; Characteristics of the processing methods; Characteristics of the processed flaxseeds.

[0309] Base 100 = unselected and untreated flaxseed as described in the table above. This digestibility trial conducted on chickens illustrates the value of both flaxseed selection and technological processing, when considered in isolation:

[0310] - Regarding energy, the impact of selection is +49%, the impact of treatment is +10% in digestibility compared to unselected or untreated seeds;

[0311] When the two levers are used jointly, it is not a simple additive effect of the impacts considered in isolation that occurs, but rather a synergy between them: - On energy, the impact of the selection and technological treatment of flax seeds, as described by the invention, is +103% compared to an unselected and untechnologically treated flax seed:

[0312] Thus, the invention as described provides a real advantage in terms of animal feed utilization. This is manifested through its energy utilization, as previously described. This results from seeds with a higher nutritional density and a more efficient processing method.

[0313] Thanks to these advantages, the invention has resulted in zootechnical results that have been unmatched in livestock farming until now.

[0314] Several zootechnical trials on monogastric animals and an in vitro trial on ruminants were conducted in different species and farms, validating the technical advantages obtained by the invention under production or extrapolation conditions. These trials are complemented by an economic feasibility study.

[0315] 1) Zootechnical trial on the laying hen

[0316] In an experimental farm, 3% of flaxseed from the invention, combined with 3% broad bean seed, was introduced into the diet of laying hens (Isa-Brown) for approximately 3 months, taking into account the values ​​of ME (metabolizable energy) and CUD N (protein digestibility) previously determined by digestibility study.

[0317] Given the methodology adopted, which consists of formulating feed for laying hens in iso-nutritional terms (metabolizable energy, digestible essential amino acids, calcium, phosphorus, etc.) taking into account the differences in digestibility values ​​evaluated earlier, the objective of this trial was to verify whether, thanks to the synergistic effect of a reduction in antinutritional factors, the invention made it possible to obtain a level of zootechnical performance at least equal to, or even greater than, that of a reference feed.

[0318] The flaxseed produced by the invention is the result of a combination of treatments, beginning with selection, which isolates seeds with specific characteristics (MG%, Omega-3, NDF, Mucilage, CRE) listed in the table below. These seeds are then ground and thermally prepared for 15 minutes by incorporating steam, raising the temperature to 45°C and the moisture content to 11%. Finally, the ground and preheated seeds are subjected to a pressure of 20 bar for 15 seconds, resulting in a temperature of 135°C.

[0319] Thus, the following is presented in the table below:

[0320] - The nutritional characteristics retained for the flaxseed from the invention on the one hand and for the flaxseed which has simply been ground on the other hand, in comparison to another standard flaxseed not tested in the laying hen, which values ​​have been previously determined by the study of their digestibility on chicken according to the usual protocols known to the person skilled in the art and referring to;

[0321] - Laying performance in terms of egg weight, mass of egg exported (taking into account the number of eggs laid) and feed conversion ratio (feed efficiency to produce 1 egg).

[0322] Table: Characteristics of rations and flaxseed for laying hens, and associated production performance

[0323]

[0324] Firstly, it emerges that the differences in digestibility values ​​between the 3 flax seeds are highly significant. The ME and CUD N values ​​increase from 1842kcal and 54% for a standard flax seed, to 2751kcal and 67% for a previously selected but only ground flax seed, to 3743kcal and 71% for the same selected flax seed that has undergone the entire process of the invention.

[0325] These production results in laying hens are directly related to the composition of the selected flaxseed, which is then treated with MG, NDF, mucilage, EM, and CUD N, on the one hand, and to the treatment's effectiveness in terms of HCN and MGD, on the other. These results stem from a positive interaction between the selection of suitable flaxseed varieties and an optimized technological process.

[0326] Therefore, it should be acknowledged, compared to the control group with soybean meal, which is already very well characterized in terms of digestibility values ​​and production performance, that:

[0327] The results obtained, in terms of hen production performance, with the "Trial only ground" flaxseed are significantly lower than with the "soybean meal" control, highlighting the negative effects of antinutritional factors on hen egg production. Indeed, it was observed that the hens in this group had a lower laying rate but a higher egg weight, meaning they exported slightly more egg mass while consuming more feed to produce the same quantity of eggs, indicating a slight loss of feed efficiency (increased feed conversion ratio).

[0328] - While the nutritional value of the "Test from the invention" flaxseed was already significantly higher than that of the "Test only ground" flaxseed, the results obtained with the flaxseed of the invention show a significant improvement in the different performance criteria.

[0329] This is how the advantage of the invention is observed. Not only does the flaxseed used in the present process exhibit superior nutritional values ​​in digestibility studies, but it also avoids the harmful effects of antinutritional factors while achieving production performance similar to soybean meal. 2) Zootechnical and economic trial on broiler chickens

[0330] In a reference farm raising fast-growing chickens, two identical buildings were fed according to two feeding programs. The standard program, based on soybean meal and oil and cereals, was compared to a feeding program including a portion of flaxseed from the invention, mixed with protein-rich seeds. This mixture, in a ratio of 70% flaxseed and 30% fava bean seeds, was distributed at a rate of 2.5% during the growth period and 3% during the finishing period.

[0331] Technical and economic performance was assessed based on data on consumption, animal weight, growth, feed conversion ratio, mortality and feed surcharge.

[0332] In this trial, the nutritional values ​​of flaxseed used in feed formulation were based on previously determined digestibility values. The objective was therefore to verify whether the zootechnical performance of the chickens was equal to or greater than that of the control group.

[0333] The table below presents the characteristics of the flax seeds, the technological treatments implemented, the treated flax seeds, and the technical and economic performance data obtained.

[0334] Thus, the technical results made possible by the invention first demonstrated the effectiveness of the process in reducing the HCN content and increasing the MGD content; and above all they compensated for the additional food cost, with a 4% improvement in the economic index.

[0335] Thus, the solution proposed by the invention has generated a significant improvement in technical (weight +4%, GMQ +4%, technical IC -4% and performance index +9%) and economic performance.

[0336] According to these zootechnical results, the digestibility values ​​of the flax seeds from the invention cannot alone explain the improvement in performance.

[0337] Indeed, while digestibility results were taken into account during feed formulation, the observed production performance is superior; a sign of a synergistic effect linked to better feed utilization of flaxseed, expressed at the animal's metabolic level, and which can be attributed to the reduction of antinutritional factors.

[0338] 3) In vitro study of fatty acid biohydrogenation in ruminants. In ruminants, dietary lipids are lipolyzed and unsaturated fatty acids are partially hydrogenated in the rumen. They are absorbed in the small intestine and, after possible desaturation, pass in part into milk and meat. This hydrogenation reaction of unsaturated fatty acids by ruminal bacteria is called biohydrogenation.

[0339] The synthesis of polyunsaturated fatty acids occurs in several stages and always begins with an initial isomerization reaction. This isomerization is carried out by various ruminal bacteria, resulting in the formation of diverse isomers. For alpha-linolenic acid (ALA), the initial isomerization reaction is followed by three reductions leading to the synthesis of 18:0 stearic acid.

[0340] The intermediates of this biohydrogenation, particularly conjugated linolenic acids (CLnA), derived from the biohydrogenation of ALA, may possess properties beneficial to human health. Vaccenic acid (transi 1-C18:1) is also produced during the biohydrogenation of ALA and can be desaturated to CLA in the udder of ruminants and in the consumer's body. Therefore, increasing its production in the rumen is also of interest, since transi 0-C18:1 is not increased to the same extent. Indeed, this latter fatty acid is indicative of ruminant dysfunction and is known to have detrimental effects on ruminant metabolism and the nutritional quality of products for humans.

[0341] The study and control of ruminal biohydrogenation of fatty acids is therefore an essential point to mimic (imitate) the effects of a grass-based diet on the one hand, and to improve the microbial balance of the rumen and the nutritional quality of ruminant production on the other.

[0342] In order to determine the interest of the invention in the feeding of ruminant animals, the disappearance of Omega 3 ALA by biohydrogenation, and their fate in different intermediate fatty acids of hydrogenation were evaluated in comparison to flax seeds in its different known forms, and in comparison to the Omega 3 ALA of a reference grass.

[0343] Flax seeds in their various known forms and those derived from the invention have all been analyzed to determine in particular the available fat content (MFC) after 10 minutes of stirring, according to the method previously described.

[0344] Differently treated seeds, oil and reference grass were introduced into Nylon (trademark) bags and then incubated in vitro in rumen juice for 2 or 6 hours. Fatty acids were analyzed in the initial products and at the end of incubation, in order to calculate a percentage of disappearance (biohydrogenation rate, which measures the efficiency of the initial isomerization step) of ALA, the fate of this ALA in CLnA and in C18:2 transi 1-cis15, the fate of the unsaturated fatty acids of the flaxseed in C18:0, but also the proportion of C18:1 trans1 1 that appeared and the ratio between C18:1 trans 1 1 and C18:1 trans 10. In order to best mimic the hydrogenation kinetics of ALA from grass, it is necessary to get close to the values ​​of these different fatty acid isomers obtained with grass.The table below presents the characteristics of the flax seeds, the technological treatments implemented, the treated flax seeds, and the results after 2 hours of incubation.

[0345]

[0346] %BH: biohydrogenation rate The first observation lies in the very high biohydrogenation of grass ALA, leading in particular to a very high proportion of C18:0, compared to ALA sources in the form of flax.

[0347] It can therefore be considered that the quantity of ALA to be distributed in the ration of ruminants in the form of flax can be reduced compared to grass, to obtain a similar quantity of ALA at the exit of the rumen, this ALA which will have escaped biohydrogenation.

[0348] On the other hand, considering an equivalent amount of ALA intake in the form of grass or flax in these different forms, we observe that:

[0349] - Raw ground flaxseed has a rapid hydrogenation kinetics leading to a very low proportion of hydrogenation intermediates, and a significant proportion of C18:0. It should be noted that the ratio C18:1 trans 11 / C18:1 trans 10 is relatively low.

[0350] - Extruded cooked flaxseed slows down the hydrogenation kinetics of ALA, leading to more hydrogenation intermediates (CLnA and C18:2 trans 11 cis 15) and C18:0, as well as a higher proportion of C18:1 trans 11 and an improvement in the C18:1 trans 11 / C18:1 trans 10 ratio.

[0351] - Linseed oil also leads to a slowing down of the hydrogenation kinetics of ALA, with some variations compared to extruded cooked linseed insofar as less C18:1 trans 11 is observed and a deterioration of the C18:1 trans 11 / C18:1 trans 10 ratio.

[0352] - the flaxseed from the invention, according to the different treatment conditions mentioned, makes it possible to obtain a kinetics of appearance of the hydrogenation intermediates of ALA similar to that of grass, with a proportion of C18:1 trans 11 closer to grass and a ratio C18:1 trans 11 / C18:1 trans 10 similar to grass.

[0353] Its hydrogenation rate becomes higher than other flax sources and tends to approach that of grass. However, it remains far from it, but this difference is compensated for by a lower C18:0 synthesis.

[0354] Following this study, it can be concluded that the flax seeds derived from the invention are indeed those that most closely resemble the grass model, it being understood that grass represents a natural, healthy, and sustainable food source, in the interest of ruminants and their health, and in the interest of the consumer. This study also confirmed that, among the flax seeds evaluated, the available fat content was a good predictor of the fate of ALA in the rumen. 4) Economic feasibility study of the process according to the present invention

[0355] In order to carry out this economic analysis, we used poultry feed formulation software, duly informed for this purpose in terms of available raw materials, nutritional values ​​of raw materials, prices of these raw materials and nutritional constraints of feed for broiler and laying hens, at different physiological stages of their production.

[0356] Thus, after providing information on the nutritional values ​​and potential prices of the best combinations of the invention, it was possible to assess the predisposition of the invention to be economically viable.

[0357] Using this same approach, it was also possible to evaluate the interest prices of raw materials produced from the best combinations of processes resulting from the invention. From this, it was observed that the invention could be entirely economically viable within the framework of a balanced diet rich in ALA Omega 3, for example, by formulating products that meet specific requirements for ALA Omega 3, such as those outlined in the specifications of the Bleu-Blanc-Cœur association.

[0358] Three feed formulas for growing broiler chickens are presented below, showing the economic advantage given to the solution resulting from the invention (a mixture of flaxseed and broad bean, at a rate of 70% and 30% respectively), due to its technical and economic priority in terms of inclusion by optimization in Bleu-Blanc-Cœur feed formulas, compared to known state-of-the-art raw materials (ground or extruded flaxseed).

[0359] Comparison table of three Bleu-Blanc-Cœur broiler chicken growth feed formulas: one from ground flaxseed, a second from extruded flaxseed and a last from flaxseed from the invention.

[0360] We can see through this formulation exercise that the solution of the invention is optimized in a "Bleu-Blanc-Cœur" broiler chicken growth feed formula, and allows savings of around €1.9 per tonne and €1.1 per tonne compared to ground flaxseed and extruded flaxseed respectively.

[0361] This formulation study demonstrates the technical and economic viability of the invention for any balanced nutritional approach in ALA Omega 3. Finally, in terms of applications, the process of the invention aims to promote the inclusion of flax seeds in feed as a substitute for other energy sources such as cereals and all lipid sources, and thus to meet the demands of farmers for healthy and high-performing animals, and the demands of consumers for access to more nutritionally balanced, safer, healthier and sustainable livestock products, and whose feed is of local origin.

[0362] The scope of application of this process can relate to two types of uses in livestock farming:

[0363] Use in the production of a raw material

[0364] Preparation of a concentrate based on flaxseed, or co-products, which becomes a raw material, for incorporation into complete or complementary feed for monogastric animals and intended for industrial feed manufacturers and / or farms. In this case, the minimum incorporation of said flaxseed, or its co-products, is 20% minimum, preferably 30% minimum, or even 40% minimum.

[0365] The other raw materials composing the concentrate may undergo all or part of the steps of the present invention, especially if it confers an advantage on these raw materials.

[0366] Thus, the preferred raw materials are protein seeds, any starchy product such as cereals, then co-products of cereals and protein seeds, oilseed cakes and sources of simple and complex carbohydrates, then all other usual raw materials in animal nutrition.

[0367] Use in food preparation

[0368] Preparation of a complete or complementary cereal feed intended for livestock farmers for feeding their monogastric animals. In this case, the minimum incorporation of said flax seeds, or their co-products, is 1% minimum, preferably 3% minimum.

[0369] Also, the products resulting from the invention are distinguished according to the needs of food manufacturers and breeders, depending on whether it is a strict positioning of Omega 3 intake without other technical consideration, or depending on whether it is local, French and "Bleu Blanc Cœur" production chains for example.

[0370] Indeed, in the case of traceable and guaranteed Omega 3 needs to meet the specifications of non-GMO or "Bleu-Blanc-Cœur", preference is given to the processing of flaxseed, or its co-products, in association with protein-rich seed.

[0371] This approach has the advantage, in the context of use by food manufacturers, of being able to provide in the same product both a source of Omega 3, but also a source of protein instead of a raw material carrier without much technical interest (cereal by-products, cereals, etc.), and thus not requiring an additional storage cell for protein seeds.

[0372] Here is an example of the wording:

[0373] Formulas for non-GMO / local protein supply chain initiatives:

[0374] Made from 50% flax seeds and 50% protein seeds;

[0375] Made with 30% flax seeds and 70% protein seeds;

[0376] Made with 15% flax seeds and 85% protein seeds;

[0377] - Formulas for the "Bleu-Blanc-Cœur" sector approach:

[0378] Made from 50% flax seeds and 50% protein seeds;

[0379] Made from 70% flax seeds and 30% protein seeds;

[0380] Based on 85% flaxseed and 15% protein-rich seeds. The seeds, or co-products, resulting from the invention can also be used for domestic animals and ruminants. Although initially developed for use in monogastric animals, the seeds processed according to the invention are perfectly suitable for feeding domestic animals such as dogs and cats, and ruminants.

[0381] It is also of interest to use the seeds and co-products resulting from the invention for use as feed for domestic animals. Flax seeds prepared in this way provide, on the one hand, a highly digestible source of Omega-3 fatty acids, and on the other hand, a source of protein with reduced allergenic potential. Indeed, due to the biochemical reactions occurring during one of the thermal stages of the process, those skilled in the art know that the allergenic risk is significantly reduced (Franck et al., 2008).

[0382] Finally, the use of this process can also be extended to the human food market due to the added nutritional value and food security it provides. This is in a context where Omega-3 intake for humans is now expected to be increased in the diets of populations in developed countries, as recommended by ANSES (ANSES, 2011).

[0383] The bibliographic references cited in this text are detailed below:

[0384] - Legrand, P., JM Bourre, B. Descomps, G. Durand and S. Renaud, 2001: Recommended nutritional intakes for the French population - Lipids. In: ET Doc ed. Recommended nutritional intakes for the French population.

[0385] - Sauvant, D., J.-M. Perez, G. Tran, V. Bontems, P. Chapoutot, B.

[0386] Doreau, C. Jondreville, SJ Kaushik, M. Lessire, W. Martin-Rosset, F. Meschy, J. Noblet, J. -L. Peyraud, H. Rulquin and B. Seve, 2004: Composition and nutritional value tables of raw materials intended for livestock.

[0387] - Hylemond, PB (1985) Metabolism of bile acids in intestinal icroflora, in: DANIELSEN, H. & SJO " VALL, J. (Eds) Sterols and Bile Acids: New

[0388] Comprehensive Biochemistry, pp. 331 -343 (Amsterdam, Elsevier Science).

[0389] - Longstaff, M. & McNab, JM (1991) The inhibitory effects of hull polysaccharides and tannins of field beans (Vicia faba L.) on the digestion of amino acids, starch and lipid and on digestive enzyme activities in young chicks. British Journal of Nutrition, 65:199-216

[0390] - Noblet, J., Y. Jacquelin-Peyraud, B. Quemeneur and G. Chesneau, 2008: Energy value of flaxseed in pigs: impact of cooking-extrusion technology. Journées Rech. Porc. 40, 203-208.

[0391] - Chesneau, G., S. Burban, F. Millet and P. Weill, 2009: Quality of oil-seed processing by cooking-extrusion: available fat. Renc. Rech. Rum. 16, 62-62.

[0392] - AFNOR. NF EN 16160 April 2012. Animal feed - Determination of hydrogen cyanide by HPLC - Animal feed

[0393] - Ikeda, K. & Kusano, T. (1983) In vitro inhibition of digestive enzymes by indigestible polysaccharides. Cereal Chemistry, 60: 260-262 - Bedford, M.R. Mechanism of action and practical environmental benefits from the use of feed enzymes. Anim. Feed Sci. Technol. 1995;25: 193- 200.

[0394] - Fengler, A. l. & Marquardt, R. R. (1988) Water-soluble pentosans from rye: II. Effects on rate of dialysis and on the rétention of nutrients by the chick. Cereal Chemistry, 65:298-302

[0395] - Choct, M. , R. J. Hughes, J. Wang, M. R. Bedford, A. J. Morgan and G. Annison, 1996: Increased small intestinal fermentation is partly responsible for the anti-nutritive activity of non-starch polysaccharides in chickens. British poultry science 37, 609-621 .

[0396] - Elboutachfaiti, R. , C. Delattre, A. Quéro, R. Roulard, J. Duchêne, F. Mesnard and E. Petit, 2017: Fractionation and structural characterization of six purified rhamnogalacturonans type I from flaxseed mucilage. Food Hydrocolloids 62, 273-279.

[0397] - Oomah, D. B. , G. Mazza and E. O. Kenaschuk, 1996: Dehulling

[0398] Characteristics of Flaxseed. LWT - Food Science and Technology 29, 245-250.

[0399] - Oomah, B. D. and G. Mazza, 1997: Effect of Dehulling on Chemical Composition and Physical Properties of Flaxseed. Lebensm. -Wiss. u. - Technol. 30, 135-140.

[0400] - Oomah, B. D. and G. Mazza, 1998: Fractionation of flaxseed with a batch dehuller. Ind. Crop. Prod. 9, 19-27.

[0401] - Akande, K. E. ; Doma, U. D. ; Agu, H. O. ; Adamu, H. M. , 2010. Major antinutrients found in plant protein sources: their effect on nutrition. Pakistan J. Nutr. , 9 (8): 827-832

[0402] - Weill, P., 2001: Detoxification process for flax seeds. In:

[0403] Valorex ed. EP1 155626 A1, France.

[0404] - Meynard J.-M., Messéan A., Charlier A., ​​Charrier F., Fares M., Le Bail M., Magrini MB, Savini I., Réchauchère O., 2014, Crop diversification: overcoming agronomic and economic obstacles, Éditions Quæ, 2014.

Claims

DEMANDS 1. Process for treating flax seeds (Linum usitatissimum) with a view to improving their value as food, particularly for animals, characterized by the fact that it comprises the following successive stages: a) Use of flax seeds provided that these seeds have: - a fat and / or Omega 3 fatty acid content higher than the values ​​indicated in the table below: (ATG = total fatty acids) and, only when said seeds are intended for feeding monogastric species, a value in water retention capacity or mucilage content, as well as a crude cellulose and / or neutral detergent fiber (NDF) content, these values / contents being lower than those indicated in the table below: And with a hydrocyanic acid content of less than 250 mg per kilogram of raw material. b) Mixing, provided that there are at least two raw materials of different nature and / or quality, then fractionation, or fractionation and then mixing, of said seeds from step a) until the seed coats and kernels of said seeds break; c) Implementation of a thermal step for preparing the seeds from step b) using steam and / or a water-based liquid, until a temperature between 30 and 90°C and a humidity above 10%, preferably 15%, is reached, the duration of this preparation being greater than 2 minutes, preferably 15 minutes; d) Applying a minimum pressure of 10 bar to the seeds or mixture from step c), for a period exceeding 10 seconds, until a temperature exceeding 80°C is reached, preferably between 100 and 150°C; and / or d bis) Heating the seeds or mixture from step d), or step c), respectively, for a minimum of 15 minutes, preferably from 30 minutes to 2 hours, at a temperature above 80°C, preferably 90 and 150°C.

2. A process according to claim 1, characterized in that the thermal step c) of preparation is carried out in the presence of at least one exogenous enzyme identified from among the following families: arabinofuranosidases, beta-glucanases, cellulases, glucoamylases, pectinases, pectin methyl esterases, phytases, proteases, xylanases and, preferably, xylanases, beta-glucanases and pectinases, said exogenous enzyme having been previously added to the seeds or mixture.

3. A process according to claim 2, characterized in that, at the thermal step c) of preparation in the presence of exogenous enzyme, the humidity is set above 15%, preferably 25%, and the preparation is carried out for at least 15 minutes, preferably 60 minutes.

4. A method according to claim 1, characterized in that during the implementation of said thermal preparation step, the mixture is agitated.

5. A method according to any one of claims 1 to 4, characterized in that, when mixing and then fractionation are carried out, a new mixing is carried out after said fractionation.

6. A method according to any one of claims 1 to 5, characterized in that said fractionation is continued until at least 90% of the seeds have a particle size of less than 2000 micrometers, preferably less than 1500 micrometers.

7. A method according to any one of the preceding claims, characterized in that the implementation of step d), or d bis), is interrupted as soon as the HCN content of said seeds reaches a value lower than that indicated in the table below and that the MGD content has a value higher than that indicated in the table below:

8. A method according to any one of the preceding claims, characterized in that, following step a), or upstream, the seeds are sorted according to a criterion chosen from size, weight, shape, density, an aerodynamic, colorimetric or electrostatic parameter.

9. A process according to any one of the preceding claims, characterized in that, following step a), the seeds are dehulled and one or the other of the fractions is used, preferably when the dehulling is characterized by a concentration of at least 3% of fat in the so-called kernel fraction, preferably at least 5%.

10. A process according to any one of the preceding claims, characterized in that, following step a) or b), the seeds, whole or hulled, are crushed, and the cake is used, preferably when it contains at least 8% fat. 1 1. A process according to any one of the preceding claims, characterized in that said flax seeds are mixed with at least one other raw material selected from the group consisting of protein seeds, cereals, cereal and protein seed co-products, sources of simple and complex carbohydrates, oilseed cakes and other oilseed co-products.

12. A process according to any one of the preceding claims, characterized in that during the implementation of at least one of said steps, at least one antioxidant substance is added to said seeds.

13. A method according to any one of the preceding claims, characterized in that it comprises a step, after the implementation of step d), respectively d bis), in which said seeds are cooled.

14. A method according to any one of the preceding claims, characterized in that said seeds are finally packaged, transported and stored protected from light.

15. A method according to any one of the preceding claims, characterized in that the said seeds are finally conditioned under at least partial vacuum, or by at least partial replacement of the air by an inert gas.