Hydrolysate obtained from insects and method for producing said hydrolysate

Abstract

The present invention relates to a hydrolysate obtained from insects, comprising at least 50% by weight of proteins, at least 7% by weight of lipids, at least 10.5% by weight of ash, the percentages by weight being indicated relative to the dry weight of the hydrolysate, and a solids content of between 15% and 35%, the percentage being given relative to the weight of the hydrolysate. The invention also relates to a method for preparing the hydrolysate, and to the use thereof in particular for improving the growth of fish.

Description

[0001] Hydrolyzate obtained from insects and manufacturing process

[0002] TECHNICAL FIELD OF THE INVENTION

[0003] The present invention relates to a hydrolysate obtained from insects as well as to its preparation process and its uses in animal feed and in particular fish feed.

[0004] Aquaculture plays a crucial role in global food security, as it is an industry that has experienced steady growth for decades. However, it faces several significant challenges, particularly in terms of food, with the increasing intensification of production and the importance of exploiting sustainable ingredients with a lower carbon footprint.

[0005] In fish feed manufacturing, the need to reduce reliance on fishmeal has led to the development of alternative ingredients, both marine and terrestrial. These new feeds, including functional supplements, can play a key role in the shift to more sustainable practices, thereby reducing the environmental footprint and improving the economic income of aquafarmers.

[0006] Thus, there is a need to find alternatives that allow optimizing development and achieving optimal growth of fish.

[0007] The work of the inventors has made it possible to demonstrate that it is possible to develop a hydrolysate obtained from insects which can significantly improve the growth performance of fish, even when introduced in small quantities.

[0008] In addition, the inventors demonstrated that the hydrolyzate also improved the consistency of feces. This latter parameter is important to consider in recirculating aquaculture systems (RAS), as it has a significant impact on water quality. Indeed, waste must be kept to a minimum and easily removed mechanically to avoid damaging the filters.

[0009] STATEMENT OF THE INVENTION

[0010] The present invention relates to a hydrolysate obtained from insects, comprising at least 50% by weight of proteins, at least 7% by weight of lipids, at least 10.5% by weight of ash, the percentages by weight being indicated on the dry weight of the hydrolysate, and a dry matter content of between 15 and 35% by weight, the percentage being given on the weight of the hydrolysate. By "hydrolysate" is meant a composition which comprises hydrolysed proteins. The hydrolysed proteins are obtained by enzymatic hydrolysis of proteins. The enzymatic hydrolysis of proteins corresponds to a cleavage of a peptide bond by an enzyme at a specific cleavage site causing the release of proteins of reduced size or even amino acids.

[0011] The hydrolyzate according to the invention is more particularly a hydrolyzed aqueous composition, that is to say that it has a humidity level of 65 to 85%, preferably 70 to 80%, even more preferably 75 to 80%. Throughout the present application, “hydrolyzed aqueous composition” and “hydrolyzate” are considered equivalent.

[0012] It should be noted that within the framework of this application, and unless otherwise stipulated, the ranges of values ​​indicated are understood to include limits.

[0013] As indicated above, the hydrolyzed aqueous composition thus comprises 15 to 35% of dry matter, preferably 20 to 32%, more preferably 20 to 25% by weight of dry matter relative to the weight of the hydrolyzate.

[0014] It should be noted that in the context of this application, the terms “weight percentage” and “mass percentages” are equivalent.

[0015] Preferably, the humidity level is determined according to the method resulting from regulation EC152 / 2009, as detailed in example 2.

[0016] Throughout the application, where no date is specified for a regulation, standard or directive, it means the regulation, standard or directive in force on the filing date.

[0017] By "insects" is meant insects at any stage of development, such as an adult, larval or nymph stage. Preferably, the insects used in the method according to the invention are edible.

[0018] More particularly, the insects may be selected from the group consisting of Coleoptera, Diptera, Lepidoptera, Isoptera, Orthoptera, Hymenoptera, Blattoptera, Hemyptera, Heteroptera, Neuroptera, Ephemeroptera and Mecoptera, preferably from Coleoptera, Diptera, Orthoptera, Neuroptera and Lepidoptera.

[0019] Preferably, the insects are chosen from the group consisting of Tenebrio molitor, Hermetia illucens, Galleria mellonella, Alphitobius diaperinus, Zophobas morio, Blattera fusca, Tribolium castaneum, Rhynchophorus ferrugineus, Musca domestica, Chrysomya megacephala, Locusta migratoria, Schistocerca gregaria, Acheta domesticus and Samia ricini.

[0020] More preferably, in the hydrolyzate according to the invention the insects are beetles. The beetles preferably used belong to the families Tenebrionidae, Melolonthidae, Dermestidae, Coccinellidae, Cerambycidae, Carabidae, Buprestidae, Cetoniidae, Dryophthoridae, or mixtures thereof, even more preferably the insects belong to the family Tenebrionidae.

[0021] More preferably, these are the following beetles: Tenebrio molitor, Alphitobius diaperinus, Zophobas morio, Tenebrio obscurus, Tribolium castaneum and Rhynchophorus ferrugineus, or their mixtures, even more preferably Tenebrio molitor and Alphitobius diaperinus.

[0022] Insects are preferably farmed and not taken from the wild.

[0023] For example, insects are raised on an insect farm. Raising insects on a specific farm not only controls and eliminates the risks associated with insect-borne diseases, but also limits the risks associated with the toxicity of insect-derived food products due, for example, to the presence of insecticides. In addition, breeding allows for control of the quality of the insect supply and limits supply costs.

[0024] Advantageously, the hydrolyzate according to the invention comprises a fiber content of between 1 and 5% by weight of the dry weight of the hydrolyzate.

[0025] Preferably, the fiber content is determined according to AOAC method 985.29, as detailed in Example 2.

[0026] Advantageously, the hydrolyzate comprises between 2% and 5%, preferably between 2.5% and 4.5%, more preferably between 3% and 4% by weight of fibers on the dry weight of the hydrolyzate.

[0027] Advantageously, the fibers include chitin.

[0028] In the context of the present application, by "proteins" is meant the quantity of crude proteins. The quantification of crude proteins is well known to those skilled in the art. For example, the Dumas method or the Kjeldhal method may be mentioned. Preferably, the Kjeldhal method is used, as detailed in Example 2. By "proteins", unless otherwise indicated, is meant not only proteins but also peptides and free amino acids.

[0029] Advantageously, the hydrolyzate comprises between 50 and 80% by weight of proteins, preferably between 55 and 70%, more preferably between 60 and 65% by weight of proteins on the dry weight of the hydrolyzate.

[0030] Advantageously, the hydrolyzate comprises at least 20% of essential amino acids, preferably between 20% and 55%, more preferably between 40% and 50% by weight of essential amino acids, the percentages by weight being expressed on the total weight of proteins in the hydrolyzate. By "total weight of proteins" or "weight of proteins" without further indication on the nature of the proteins, is meant the weight of crude proteins present in the hydrolyzate. This therefore includes water-soluble and insoluble proteins.

[0031] Preferably, the level of essential amino acids is determined according to ISO 13903:2005 and EC152 / 2009 regulation (for tryptophan).

[0032] Essential amino acids are defined as the following amino acids: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. It should be noted that for some species, other amino acids may also be essential, for example, arginine for fish.

[0033] Advantageously, the hydrolyzate comprises at least 1% by weight of free amino acids, preferably between 2 and 15%, more preferably between 3% and 11% of free amino acids, the percentages being indicated on the dry weight of the hydrolyzate.

[0034] Preferably, the free amino acid level is determined according to the ISO 13903:2005 method, as detailed in Example 2.

[0035] The 5 most abundant total amino acids are advantageously glutamic acid, aspartic acid, leucine, lysine and tyrosine.

[0036] These amino acids are of particular interest for fish health (e.g., intestinal health and hormone secretion for glutamic acid and muscle protein synthesis for leucine).

[0037] The hydrolyzate according to the invention preferably comprises from 40 to 60% by weight of insoluble proteins, the percentage by weight being expressed relative to the total weight of proteins. Therefore, the hydrolyzate according to the invention comprises 40 to 60% by weight of water-soluble proteins, the percentage by weight being expressed relative to the total weight of proteins.

[0038] Advantageously, the hydrolyzate according to the invention comprises water-soluble proteins, 75% of the water-soluble proteins having a size of less than 12400 g / mol, based on the total weight of water-soluble proteins.

[0039] By "water-soluble proteins" is meant, among the proteins (or crude proteins), those which are soluble in a solution consisting of 30% acetonitrile, 70% ultrapure water and 0.1% trifluoroacetic acid ("ACN / water / TFA solution"), the percentages being percentages by volume on the total volume of solution, as detailed in example 2.

[0040] By "insoluble proteins" we mean proteins insoluble in the ACN / water / TFA solution, as detailed in Example 2.

[0041] Advantageously, the hydrolyzate comprises a content greater than 80%, preferably between 85% and 98%, more preferably between 90% and 95% by weight of water-soluble proteins having a size less than 12400 g / mol, on the total weight of water-soluble proteins.

[0042] Advantageously, the hydrolyzate comprises a content greater than 40%, preferably between 50% and 70%, more preferably between 55% and 60% by weight of water-soluble proteins having a size less than 555 g / mol, on the total weight of water-soluble proteins.

[0043] Preferably, the size of the proteins is determined by HPLC-SEC as detailed in Example 2.

[0044] The small size of the proteins in the hydrolyzate according to the invention makes this hydrolyzate very digestible.

[0045] Advantageously, the hydrolyzate has a pepsin and / or ileal digestibility greater than or equal to 95% by weight, preferably greater than or equal to 96% and more preferably greater than or equal to 98%, and more particularly greater than or equal to 99%, by weight of the total weight of proteins.

[0046] Preferably, pepsin digestibility is measured according to AOAC 971.09, AOAC 992.15; AOAC 990.03 and AOCS Ba 4e-93 methods, as detailed in Example 2.

[0047] Ileal digestibility is measured according to the BOISEN and DUMAS methods, as detailed in example 2.

[0048] As indicated above, the hydrolyzate according to the invention comprises at least 7% by weight of lipids, expressed on the dry weight of the hydrolyzate. Preferably, the hydrolyzate comprises between 7% and 20% by weight of lipids, preferably between 8% and 18% by weight, more preferably between 9% and 16% by weight of lipids on the dry weight of the hydrolyzate.

[0049] Methods for determining fat (lipid) content are well known to those skilled in the art. Preferably, the determination of this content will be carried out following the method of EC Regulation 152 / 2009, as detailed in Example 2.

[0050] As indicated above, the hydrolyzate according to the invention comprises at least 10.5% by weight of ash, expressed on the dry weight of the hydrolyzate. Advantageously, the hydrolyzate comprises an ash content of between 11% and 35% by weight, preferably between 12% and 30% by weight, more preferably between 15 and 28% by weight on the dry weight of the hydrolyzate.

[0051] Preferably, the ash content is determined according to a method of EC Regulation 152 / 2009 as detailed in Example 2.

[0052] Advantageously, the hydrolyzate according to the invention comprises one or more additives chosen from a preservative and / or a pH lowerer. The additives added to the hydrolyzate are intended to stabilize it. As a result, the hydrolyzate can be stored for a period of more than 6 months, such as for example between 6 and 12 months at a temperature of 30 degrees Celsius.

[0053] Preferably, the preservative is selected from sodium formate, sorbic acid, formic acid, potassium diformate, calcium formate, sodium bisulfate, potassium sorbate, acetic acid, sodium diacetate, calcium acetate and prenyl acetate.

[0054] The preservative is preferably introduced into the hydrolyzate at a concentration of 0.05 to 3%, preferably 0.1 to 2% by weight of the weight of the hydrolyzate.

[0055] A "pH lowerer" means a product capable of lowering the pH of an aqueous solution.

[0056] Preferably the pH lowerer is chosen from an organic or inorganic acid, preferably an inorganic acid, such as for example phosphoric acid, citric acid, fumaric acid, acetic acid, sorbic acid or propionic acid.

[0057] Advantageously, the pH lowerer is introduced in a quantity necessary and sufficient to lower the pH between 2 and 4, preferably between 2.5 and 3.5, such as for example between 2.8 and 3.2.

[0058] The present invention also relates to a process for preparing a hydrolysate from insects comprising the following steps: a) Separation of the cuticles and the soft part of the insects, b) Separation of the soft part of the insects into an aqueous fraction, an oily fraction and a solid protein fraction, and c) Enzymatic hydrolysis of the solid protein fraction.

[0059] The process according to the invention makes it possible to obtain the hydrolyzate according to the invention.

[0060] The hydrolyzate and insects are as described above, with their advantageous and preferential modes.

[0061] Thus, in the process according to the invention, the enzymatic hydrolysis is carried out on the solid protein fraction and consequently after the separation of the soft part into three fractions. The inventors have demonstrated that carrying out the hydrolysis step on the solid protein fraction, after the separation of the soft part into three fractions, presented advantages in comparison with a process where the hydrolysis would be carried out before the separation step into three fractions and in particular made it possible to improve the profitability of the process and to keep the other fractions unaltered.

[0062] Preferably, the method according to the invention further comprises a step of killing the insects, prior to the step of separating the cuticles from the soft part. This killing step is more fully described in step 1 of the method according to the invention detailed below.

[0063] The cuticle is the outer layer (or exoskeleton) secreted by the epidermis of insects. It is generally made up of three layers: the epicuticle, the exocuticle, and the endocuticle.

[0064] The term "soft part" refers to the flesh (including muscles and viscera) and juice (including biological fluids, water and hemolymph) of insects. In particular, the soft part does not consist of insect juice.

[0065] Separation of the cuticles from the soft part of insects can be carried out using any suitable type of separator, such as a belt separator or a twin-screw separator.

[0066] The separation of the cuticles from the soft part of the insects is more fully described in step 2 of the method according to the invention detailed below.

[0067] Advantageously, the method according to the invention further comprises a step of maturation of the soft part of the insects, between the step of separation of the cuticles from the soft part and the step of separation of the soft part of the insects into an oily fraction, a solid fraction and an aqueous fraction.

[0068] By "stage of maturation of the soft part of the insects", we mean more specifically a stage during which the soft part of the insects is subjected to heating and / or agitation.

[0069] This step is more fully described in step 3 of the method according to the invention detailed below.

[0070] The three-fraction separation aims to recover three fractions from the soft part of the insects obtained in step 2 or optionally step 3, namely a solid fraction, an aqueous fraction, and an oily fraction.

[0071] This step of separation into three fractions is more fully described in step 4 of the process according to the invention detailed below.

[0072] The solid protein fraction (also called “protein cake”) is then subjected to an optional dilution step and then to enzymatic hydrolysis.

[0073] The dilution step aims to reduce the dry matter, preferably to a content between 15 and 35% by weight.

[0074] The enzymatic hydrolysis step is carried out only on the solid fraction resulting from the separation into 3 fractions. It preferably uses at least one proteolytic enzyme, preferably a protease, and more preferably at least two proteases, said proteases being of different natures. In the present application, the names or suffixes “peptidase” and “protease” are used interchangeably to designate an enzyme lysing a peptide bond of proteins. Advantageously, it uses an aminopeptidase and a serine endopeptidase.

[0075] This step of enzymatic hydrolysis of the solid protein fraction (protein cake) is more fully described in step 6 of the process according to the invention detailed below.

[0076] The method according to the invention is detailed in more detail below.

[0077] Detailed method of treating insects according to the invention

[0078] • Step 1: Killing the insects

[0079] This first stage of slaughter can advantageously be carried out by thermal shock, such as scalding or blanching. This first stage allows the insects to be killed while reducing the microbial load (reducing the risk of spoilage and health) and inactivating the internal enzymes of the insects which can trigger autolysis, and thus rapid browning of the insects.

[0080] For scalding, the insects, preferably larvae, are scalded in water for 2 to 20 minutes, preferably 5 to 15 minutes. Preferably, the water is at a temperature between 87 and 100°C, preferably 92 to 95°C.

[0081] The quantity of water introduced during scalding is determined as follows: the ratio of the volume of water in ml to the weight in g of insect is preferably between 0.3 and 10, more preferably between 0.5 and 5, even more preferably between 0.7 and 3, even more preferably of the order of 1.

[0082] For blanching, the insects, preferably larvae, are blanched in water or steam (nozzles or steam bed) at a temperature between 80 and 105°C, preferably between 87 and 105°C, more preferably between 95 and 100°C, even more preferably 98°C or in water at a temperature between 90 and 100°C, preferably between 92 and 95°C (by spray nozzles) or in mixed mode (water + steam) at a temperature between 80 and 130°C, preferably between 90 and 120°C, more preferably between 95 and 105°C, even more preferably 98°C. When the insects are blanched only with steam, the blanching is advantageously carried out in forced steaming blanching plants. The residence time in the bleaching chamber is between 5 seconds and 15 minutes, preferably between 1 and 7 minutes.

[0083] Advantageously, following slaughter step 1, the insects are directly used for implementing step 2 of separating the cuticles from the soft part of the insects, i.e. the insects are not subjected to any treatment, such as grinding, freezing or dehydration between step 1 and step 2. • Step 2: Separation of the cuticles from the soft part of the insects

[0084] Step 2 aims to separate the cuticles from the soft part of the insects.

[0085] Separation of the cuticles from the soft part of insects can be done using any suitable type of separator.

[0086] According to a first embodiment, the separation of the cuticles from the soft part is carried out using a filter press.

[0087] Advantageously, the filter press used in the insect treatment process according to the invention is a belt filter press.

[0088] A belt filter press consists of two perforated clamping bands (also called "filter cloths"). Insects are placed between the two perforated clamping bands so that the soft part of the insects is forced through the perforations of the clamping bands by pressure, while the solid part of the insects remains between the two perforated clamping bands.

[0089] The person skilled in the art is able to determine the diameter of the perforations of the clamping bands as well as the pressure to be exerted, allowing the separation of the cuticles from the soft part of the insects.

[0090] According to a second embodiment, the separation of the cuticles from the soft part is carried out using a strip separator.

[0091] For example, a belt separator may include a clamping belt and a perforated drum, the clamping belt surrounding at least a portion of the perforated drum.

[0092] The clamping band allows the insects to be brought and applied against the perforated drum so as to force, by pressure, the soft part of the insects through the perforations of the drum, while the solid part of the insects (cuticles) remains outside the drum.

[0093] The cuticles can then be removed using a scraper knife.

[0094] Concerning the pressure, the person skilled in the art is able to determine the pressure to be exerted allowing the separation of the cuticles from the soft part of the insects.

[0095] According to a third embodiment, the separation of the cuticles from the soft part is carried out using a twin-screw separator. Such a separator comprises a double screw inside a perforated drum. The soft part of the insects passes through the perforations of the drum while the cuticles are conveyed along the two screws to the outside of the separator.

[0096] Advantageously, the diameter of the perforations of the drums is between 0.5 and 3 mm, preferably between 1 and 2 mm. This insect separation step differs from conventional pressing in that it allows a (clean) separation of the soft part and the cuticles of the insects and not a separation of a juice from a solid fraction.

[0097] The soft part obtained in step 2 comprises between 20 and 50% by weight of lipids, preferably between 30 and 40% by weight of lipids on the dry weight of the soft part.

[0098] Furthermore, the soft part comprises at least 45%, preferably at least 48%, more preferably at least 50% by weight of proteins on the dry weight of the soft part.

[0099] • Step 3 (optional): Maturation of the soft part of the insects

[0100] The soft part of the insects is then, optionally, subjected to a maturation stage in a vat.

[0101] Advantageously, maturation is carried out for a period of between 15 minutes and 3 hours, preferably for 1 hour.

[0102] Advantageously, the maturation is carried out at a temperature between 65 and 100°C, preferably between 85 and 100°C, more preferably at a temperature of approximately 90°C.

[0103] This step can also be subject to agitation.

[0104] This step helps to facilitate the separation of the soft part of the insects in step 4 below.

[0105] Preferably, the method according to the invention comprises such a step.

[0106] In particular, no dilution of the soft part of the insects in a solvent such as water is necessary in this step.

[0107] • Step 4: Separation of the soft part into a solid fraction, an aqueous fraction and an oily fraction

[0108] The aim of this step is to recover three fractions from the soft part of the insects obtained in step 2 or 3, namely a solid fraction, an aqueous fraction, and an oily fraction.

[0109] According to a first embodiment, this step of separating the soft part is carried out in two sub-steps.

[0110] In the first sub-step, the soft part of the insects is subjected to decantation using a 2-phase decanter, so as to obtain a solid fraction and a liquid fraction.

[0111] In the second sub-step, the liquid fraction is subjected to centrifugation, so as to recover an oily fraction and an aqueous fraction.

[0112] Advantageously, in this second sub-step, a plate centrifuge is used. According to a second embodiment of step 4, the soft part of the insects is subjected to decantation using a 3-phase decanter, so as to directly obtain an aqueous fraction, an oily fraction and a solid fraction.

[0113] Suitable 3-phase decanters are, for example, the Tricanter® from Flottweg, or 3-phase decanters from GEA, such as the CA 225-03-33 decanter.

[0114] Advantageously, the separation of the soft part is carried out according to the second embodiment.

[0115] Indeed, the use of a 3-phase decanter allows for particularly effective phase separation. More specifically, the solid fraction obtained has a high dry matter content, the aqueous fraction has little insoluble sediment (from the solid fraction) and oil, and the oily fraction has little insoluble sediment (from the solid fraction) and water.

[0116] • Step 5 (optional): Dilution

[0117] The solid fraction obtained at the end of step 4 (protein cake) is then optionally diluted by adding water in order to reduce the dry matter content of said fraction. More particularly, the dilution step is carried out by adding water, such as tap water or soft water. This step is preferably carried out with stirring. In addition, heating may also be applied, for example heating from 30 to 80°C, preferably from 40 to 70°C, more preferably from 50 to 70°C.

[0118] At the end of the dilution step, the diluted solid fraction has a dry matter content of between 15 and 35% by weight, preferably between 20 and 25% by weight.

[0119] • Step 6: Enzymatic hydrolysis

[0120] The aim of enzymatic hydrolysis is to reduce the size of the proteins in the protein cake to make them more soluble and digestible.

[0121] The enzymatic hydrolysis is carried out by at least one proteolytic enzyme, preferably a protease. In the present application, the names or suffixes “peptidase” and “protease” are used interchangeably to designate an enzyme lysing a peptide bond of proteins.

[0122] Advantageously, the hydrolysis is carried out for a period of 1 to 6 hours, preferably for 2 to 4 hours, at a temperature of 45 to 75°C, preferably 50 to 65°C and at a pH of between 6 and 8, preferably between 7 and 7.5.

[0123] The enzymatic hydrolysis can be carried out with a single protease or alternatively with a mixture of enzymes containing at least one protease, more preferably a mixture of enzymes containing several proteases. Preferably, the protease is chosen from the group consisting of aminopeptidases, metallocarboxypeptidases, serine endopeptidases, cysteine ​​endopeptidases, aspartic endopeptidases, metalloendopeptidases. Advantageously, the enzymes can be chosen from the following:

[0124] [Table 1]

[0125] *na: not applicable

[0126] Advantageously, the enzymatic hydrolysis step is carried out with a mixture comprising or consisting of an endopetidase and an aminopeptidase, more preferably, a serine endopetidase and an aminopeptidase. The enzyme or mixture of enzymes is introduced in an amount ranging from 2.5 to 31 g / kg relative to the dry weight of the solid protein fraction, preferably from 4 to 21 relative to the dry weight of the solid protein fraction.

[0127] In terms of enzymatic activity, the quantity of enzyme or enzyme mixture introduced corresponds to an activity between 40 and 5000 lll / Kg relative to the dry weight of the solid protein fraction.

[0128] More specifically, the amount of serine endopeptidase introduced corresponds to an activity of between 40 and 60 μl / kg relative to the dry weight of the solid protein fraction. Similarly, the amount of aminopeptidase introduced corresponds to an activity of between 2500 and 5000 μl / kg relative to the dry weight of the solid protein fraction.

[0129] Preferably, the process according to the invention further comprises a step of stabilizing the hydrolyzed protein solid fraction obtained in step c), by adding one or more additives chosen from a preservative and / or a pH lowerer.

[0130] The additives are as described above, with their advantageous and preferential modes.

[0131] The present invention also relates to the use of the hydrolyzate according to the invention in an animal feed.

[0132] Preferably, the animals are chosen from domestic animals, pasture animals, farmyard animals or even aquatic animals.

[0133] Advantageously, domestic animals are chosen from dogs, cats, birds, rodents, terrestrial reptiles, and fish.

[0134] Advantageously, the grazing animals are chosen from cattle, sheep, goats, pigs, equines, camelids and deer.

[0135] Advantageously, farmyard animals are chosen from chicken, turkey, duck, goose, pigeon, quail, pheasant and ostrich.

[0136] Advantageously, the aquatic animals are chosen from seabirds, cetaceans, marine reptiles, crustaceans (for example, shrimp), fish, preferably farmed fish.

[0137] Farmed fish are preferably sea bass, sea bream, gilthead sea bream, sturgeon, meagre, panga, salmon, tilapia, turbot or trout.

[0138] Preferably, farmed fish are chosen from Salmonidae and include salmon and trout.

[0139] Preferably, the fish belong to the genus Salmo, Salvelinus, Onchorynchus, and / or Hucho, more preferably Salmo.

[0140] Particularly preferred species according to the invention are: Salmo salar (Atlantic salmon), Salmo trutta (Brown trout or Brown trout), Oncorhynchus kisutch (Pacific salmon), Oncorhynchus tshawytscha (King salmon), Onchorynchus mykiss (Rainbow trout) and Salvelinus alpinus (Arctic char).

[0141] Farmed fish are fish raised in freshwater or saltwater tanks or cages. The environment, water quality, and feed are all controlled.

[0142] For example, closed-circuit farming systems (Recirculating Aquaculture Systems) can be used in fish farming. Preferably, in the use according to the invention, the feed is in the form of granules, flakes, pâté, kibble or treats.

[0143] Advantageously, the food is in the form of granules or flakes. This form is particularly suitable for feeding aquatic animals such as fish.

[0144] Such a feed comprises, in addition to the hydrolysate, other ingredients suitable for feeding fish. These ingredients may include fish oils, animal meal such as krill meal, fish meal or squid meal; cereal flours such as wheat flour; oilseed meals such as soybean meal, pea flour; vegetable oils such as rapeseed oil; gelling agents such as guar gum; protein concentrates; wheat or corn gluten; vitamin and mineral premixes or any other ingredients suitable for feeding fish.

[0145] Food in the form of pâté or kibble is particularly suitable for feeding domestic animals such as dogs or cats.

[0146] Advantageously, in the use according to the invention, the food comprises from 1% to 20% by weight of the hydrolyzate, the percentage by weight being indicated on the weight of the food.

[0147] Advantageously, the food comprises between 1% and 10% by weight of the hydrolyzate, preferably between 1% and 8% by weight, more preferably between 1% and 5% by weight of the hydrolyzate, the percentage being indicated on the weight of the food.

[0148] Fish food is most often prepared in the form of pellets.

[0149] The manufacture of granules is well known to those skilled in the art. The granules can in particular be obtained by extrusion.

[0150] According to a first embodiment, the hydrolyzate is mixed with the other ingredients constituting the food as illustrated above, before extrusion or shaping.

[0151] According to a second embodiment, firstly the other ingredients of the food are extruded then the hydrolysate is introduced in the form of a coating applied under vacuum.

[0152] The techniques for coating granules and the conditions to be implemented are well known to those skilled in the art.

[0153] The use according to the invention is advantageously implemented to improve the growth of farmed fish.

[0154] The addition of the hydrolyzate according to the invention to the fish feed makes it possible to significantly improve the body weight gain and / or the size (length) of said fish, preferably the body weight gain and the size of said fish as demonstrated in example 3 and in figure 1.

[0155] More particularly, the use of the hydrolysate according to the invention makes it possible to: increase weight gain, increase the specific growth rate, reduce the feed conversion ratio, and / or increase the slaughter yield of farmed fish, and in particular salmonids.

[0156] Preferably, the use of the hydrolyzate according to the invention makes it possible to increase weight gain, to increase the specific growth rate, and to reduce the feed conversion ratio of farmed fish, and in particular salmonids.

[0157] The hydrolyzate according to the invention, the farmed fish and the salmonids are more particularly those described above, including their advantageous and preferred embodiments.

[0158] The use according to the invention is advantageously implemented for improving the consistency of feces.

[0159] "Consistency of feces" means the degree of cohesion of the materials constituting the feces. This consistency can be measured on a scale from 1 to 4 as shown in Example 4.

[0160] By "improving consistency" we mean an increase in the cohesion of the materials constituting the feces, in particular an increase in the rate of solid and firm feces (such as score 1) and a decrease in the rate of liquid feces (diarrhea, runny digestate, scores 3-4).

[0161] A high consistency of feces is interesting for an application in aquaculture, which requires having a high water quality to avoid damaging the biofilters.

[0162] The present invention also relates to an animal feed comprising 1 to 20% by weight of the hydrolysate according to the invention, the percentage by weight being given on the weight of the feed.

[0163] BRIEF DESCRIPTION OF THE FIGURES

[0164] Other characteristics and advantages of the invention will appear in the following examples, given for illustrative purposes, with reference to:

[0165] - Figure 1 which represents six diagrams (Figures 1a) to 1f)) comparing the overall growth performances of rainbow trout fed for 84 days with the control diet (CTRL) with those of rainbow trout fed with the experimental diet according to the invention (Hydrolysate). The diets and the parameters measured are detailed in more detail in Example 3 below.o Figure 1 a) compares the final weight of the trout expressed in grams obtained according to the two diets tested; o Figure 1 b) compares the final length of the trout, expressed in centimeters, obtained according to the two diets tested; o Figure 1 c) compares the weight gain of the trout expressed as a percentage determined according to the two diets tested; o Figure 1 d) compares the specific growth rate of the trout expressed as a percentage per day determined according to the two diets tested; o Figure 1e) compares the daily feed intake of the trout determined (as a percentage of body weight per day, on the ordinate) according to the two diets tested; o Figure 1f) compares the feed conversion ratio of the trout determined according to the two diets tested.

[0166] Figure 2, which is a bar chart comparing the slaughter yield in salmon when fed with the feed according to the invention comprising the hydrolysate obtained from insects, or with the control diet;

[0167] Figure 3, which is a bar chart comparing the consistency of feces in salmon when the latter is fed with the feed according to the invention comprising the hydrolysate obtained from insects, or with the control diet; with on the ordinate, the percentage distribution of feces according to their consistency (i.e., score 1 or 2).

[0168] Figure 4 represents four diagrams (Figures 4a) to 4d)) comparing the overall growth performance of Atlantic salmon fed for 58 days with the control diet (CTRL2) with that of Atlantic salmon fed with the experimental diet according to the invention (Hydrolysate). The diets and the parameters measured are further detailed in Example 5 below. o Figure 4a) compares the final weight of the salmon expressed in grams obtained according to the two diets tested; o Figure 4b) compares the final length of the salmon, expressed in centimeters, obtained according to the two diets tested; o Figure 4c) compares the specific growth rate of the salmon expressed as a percentage per day determined according to the two diets tested; o Figure 4d) compares the feed conversion ratio of the salmon determined according to the two diets tested.

[0169] 1: Process for preparing the hydrolyzate according to the invention

[0170] First, 1 kg of T. molitor larvae are steamed and then decapitated using a twin-screw separator, thus allowing the separation of the cuticles and the pulp (flesh).

[0171] The pulp thus obtained is placed in a maturation tank for 1 hour at 90°C with stirring. The heated pulp is then separated via a tricanter (3-phase decanter) thus obtaining an oily fraction, an aqueous fraction and a solid protein fraction corresponding to a protein cake.

[0172] The protein cake is then diluted by adding water to reduce the dry matter from 42% to 22%.

[0173] Then the hydrolysis step is carried out at 60°C for 2 hours using the following enzymes:

[0174] - Alcalase: introduced at a concentration between 40-60 IU / Kg expressed in relation to the dry weight of the protein cake;

[0175] Flavourzyme: introduced at a concentration between 2500-5000 IU / kg expressed relative to the dry weight of the protein cake.

[0176] The enzymes are then deactivated at 90°C for 30 minutes and the resulting hydrolysate is cooled to 40°C before being stabilised by adding additives to achieve a pH below 2.9. The additives used may include a preservative and / or a pH lowering agent.

[0177] The preservative may be selected from sodium formate, sorbic acid, formic acid, potassium diformate, calcium formate, sodium bisulfate, potassium sorbate, acetic acid, sodium diacetate, calcium acetate and prenyl acetate.

[0178] The pH lowerer may be chosen from an organic or inorganic acid, preferably an inorganic acid, such as for example phosphoric acid, citric acid, fumaric acid, acetic acid, sorbic acid, propionic acid.

[0179] Finally, a filtration step is carried out to remove residual cuticle particles.

[0180] The finished product obtained is a hydrolyzate (or hydrolyzed aqueous composition) with a dry matter content of between 20-25%. according to the invention

[0181] The hydrolyzate obtained in Example 1 was characterized as follows. 1. Analyses

[0182] 1.1 Determination of humidity level

[0183] The humidity level was determined according to the method from EC Regulation 152 / 09.

[0184] • 1.2 Determination of the quantity of proteins

[0185] The protein content was determined according to the Kjeldahl method, of EC Regulation 152 / 2009, with a conversion factor N to protein of 6.25.

[0186] • 1.3 Determination of the quantity of lipids

[0187] The amount of lipids was determined according to EC Regulation 152 / 2009.

[0188] • 1.4 Determination of the quantity of ash

[0189] The ash content was determined according to EC Regulation 152 / 2009.

[0190] • 1.5 Determination of the quantity of fibers

[0191] The fiber content (soluble and insoluble) was determined according to the AOAC 985.29 method.

[0192] • 1.6 Determination of the quantity of amino acids

[0193] The amount of total and free amino acids was determined according to ISO 13903:2005 (for total and free amino acids except tryptophan) and EC Regulation 152 / 2009 (for tryptophan).

[0194] The amount of free amino acids was determined according to ISO 13903:2005.

[0195] • 1.7 Determination of pepsin digestibility

[0196] Peptic digestibility was determined according to AOAC 971.09 (pepsic digestibility at 0.02% (Gravimetry)) and AOAC 992.15; AOAC 990.03; AOCS Ba 4e-93 (protein combustion) methods.

[0197] • 1.8 Determination of ileal digestibility

[0198] Ileal digestibility was determined according to the BOISEN methods (for enzyme dosage) and the Dumas method (for protein content).

[0199] • 1.9 Determination of the quantity of soluble and insoluble proteins

[0200] The quantity of soluble proteins was determined by solubilizing said proteins in a solution consisting of 30% acetonitrile, 70% ultrapure water and 0.1% trifluoroacetic acid (“ACN / water / TFA solution”), these percentages being percentages by volume on the total volume of solution, which constitutes the mobile phase before determination by HPLC-SEC (size exclusion chromatography method known to those skilled in the art). The quantity of insoluble proteins was determined by the dry residue obtained after dissolving a sample of dried hydrolyzate in the ACN / water / TFA solution, and related to the initial dry weight.

[0201] • 1.10 Determination of protein size

[0202] Protein size was determined by HPLC-SEC.

[0203] • 1.11 Determination of the quantity of minerals

[0204] The content of each of the minerals listed in Table 8 below was determined by ICP / AES (inductively coupled plasma-atomic emission spectrometry).

[0205] • 1.12 Determination of the quantity of vitamins

[0206] The thiamine hydrochloride (vitamin B1-HCl) content was determined according to the BS EN 14122-2014 method.

[0207] Vitamin B12 (cyanocobalamin) content was determined according to AOAC method 952.20.

[0208] The riboflavin (vitamin B2) content was determined according to the EN 14152:2014 method.

[0209] The niacin (vitamin B3) content was determined according to the EN 15652:2009 method.

[0210] The pantothenic acid (vitamin B5) content was determined according to the AOAC 2012.16 method.

[0211] The pyridoxine (vitamin B6) content was determined according to the EN 14164:2014 method.

[0212] The phylloquinone (vitamin K1) content was determined according to the EN 14148:2003 method.

[0213] 2. Results

[0214] The characteristics of the hydrolyzate according to the invention are presented in tables 2 to 8 below.

[0215] [Table 2]

[0216] Average results calculated on 20 hydrolysates, except for fibers where a single measurement was made.

[0217] Table 2: Composition of the hydrolyzate

[0218] • Proteins and amino acids

[0219] [Table 3]

[0220] *g / 100g: g / 100g of hydrolyzate in dry weight **average results calculated on several hydrolysates Table 3: Amino acid content in the hydrolyzate

[0221] [Table 4]

[0222]

[0223] *g / 100g: g / 100g of hydrolyzate in dry weight **average results calculated on several hydrolysates Table 4: Free amino acid content [Table 5]

[0224] Table 5: Size of water-soluble proteins

[0225] [Table 6]

[0226] ^average results calculated on several hydrolysates

[0227] Table 7: Vitamin content

[0228] [Table 8] ^average results calculated on several hydrolysates

[0229] Table 8: Mineral content

[0230] Example 3: Introduction of the hydrolyzate according to the invention into fish feed (rainbow trout) a. Materials and Methods

[0231] A fish meal diet (CTRL) was formulated with ingredients meeting the known nutritional needs of rainbow trout. Based on this diet, another diet comprising the hydrolysate obtained according to Example 1 was prepared (see Table 9 below). [Table 9]

[0232]

[0233] *% of dry matter in relation to the total weight of the composition

[0234] 1Premix: This is a vitamin and mineral premix comprising the following ingredients: Butylated Hydrotoluene (BHT) (E 321) 20,000 mg, Colloidal Silica (E 551 b) 176,700 mg, Sepiolite (E 562) 370,600 mg, Vitamin B2 3,000 mg, Vitamin B12 10 mg, Nicotinamide (3a315) 20,000 mg, Folic Acid (3a316) 1,500 mg, Vitamin D3 (3a671) 200,000 IU, Vitamin A (3a672a) 2,000,000 IU, Vitamin E (3a700) 10,000 mg, Vitamin K3 (3a710) 2,500 mg, Vitamin B1 (3a821) 3,000 mg, Vitamin B6 / pyridoxine hydrochloride (3a831) 2,000 mg, D-calcium pantothenate (3a841) 10,000 mg, Biotin (3a880) 300 mg, Inositol (3a900) 50,000 mg, Betaine anhydrous (3a920) 50,000 mg, Iron (iron (II) sulfate, monohydrate) (3b103) 600 mg, Iodine (potassium iodide) (3b201) 50 mg, Manganese (manganese (II) oxide) (3b502) 960 mg, Zinc (zinc sulfate, monohydrate) (3b605) 750 mg, Copper (copper sulfate, pentahydrate) (E 4) 900 mg, Selenium (sodium selenite) (E 8) 1 mg.

[0235] Table 9: Composition of experimental diets

[0236] These two diets were manufactured by extrusion using standard techniques known to those skilled in the art so as to obtain granules having a size of 2 to 4 mm.

[0237] During extrusion, the food is dried and then cooled.

[0238] For pellets according to the CTRL regime, the pellets are obtained by extruding a composition prepared from LT fish meal, wheat gluten, soy concentrate, soy lecithin, wheat flour, premix, guar gum and hemoglobin in the amounts indicated in Table 8, which are mixed for extrusion. Then, after extrusion, after cooling the extruded pellets, an additional 7% by weight of fish oil is added by vacuum coating.

[0239] For the granules according to the invention, the granules are obtained by extrusion of a composition prepared from LT fish meal, wheat gluten, soy concentrate, soy lecithin, wheat flour, premix, guar gum and hemoglobin according to the quantities indicated in Table 8, which are mixed for extrusion. Then, at the end of the extrusion, after cooling of the extruded granules, two successive coatings are carried out according to the following steps:

[0240] 1 ère step: addition of the hydrolyzate (4% by weight of the composition at a content of 25% dry matter, i.e. 1% of dry matter relative to the total weight of the composition of the granules) to the extruded granules by vacuum coating, 2 ème step: low temperature drying of the granule coated with the hydrolyzate, 3 èmeStep: Addition of 7% additional weight of fish oil by vacuum coating. b. Growth performance test

[0241] Each diet was tested in quadruplicate (4 tanks per diet).

[0242] Rainbow trout were acclimatized for 15 days before the start of the growth trial, after which 25 trout with an average weight of 20–30 g were randomly distributed in each tank (20 tanks in total). The tanks used were cylindrical fiberglass tanks (volume: 500 L) connected to a recirculating aquaculture system (RAS).

[0243] The tanks were supplied with freshwater at temperatures between 15 ± 1 °C, with dissolved oxygen levels greater than 7 ± 1 mg / L. Ammonium and nitrite concentrations in the water were monitored daily to maintain them below toxic levels. The fish were kept on a 12-hour light / dark photoperiod.

[0244] Fish were hand-fed to apparent satiation once daily for 84 days (between 8:00 and 9:00 a.m.) up to a maximum of 3% of daily feed biomass intake.

[0245] After 84 days of experimental feeding, all fish in each tank were sampled, anesthetized with MS222, and growth performance was assessed.

[0246] Parameters measured for growth assessment:

[0247] PCI (g): Initial body weight

[0248] PCF (g): Final body weight

[0249] TCS (% / day): Specific growth rate = [(In PCF-ln PCI) / days] x 100 LTI (cm): Initial total length Tl

[0250] LTF (cm): Final total length

[0251] GP (%): Weight gain = [(PCF-PCI) / PCI] x 100

[0252] RCA: Feed conversion ratio = [total feed intake (g) / GP (g)]

[0253] PAJ (% body weight / day): Daily food intake = (gross food intake / (PCI +PCF) / 2 / days) x 100

[0254] Results :

[0255] [Table 10]

[0256] *"Hydrolysate" means the diet comprising the hydrolysate according to the invention. Table 10: Results on fish growth performance

[0257] Values ​​are expressed as mean ± standard deviation (n=4).

[0258] Asterisks indicate significant differences between experimental groups and the CTRL control group (Student's t test, P < 0.05; n = 4).

[0259] Conclusion :

[0260] After 84 days of experimental feeding, it was observed that for an equivalent daily intake, the body weight and body length of the fish fed with the pellets according to the invention had significantly increased compared to the fish fed with the CTRL pellets (see figure 1).

[0261] Thus, the inventors have demonstrated that the use of the hydrolyzate according to the invention at a very low dosage (1% in dry matter) has a significant impact on the growth of fish.

[0262] Example 4: Introduction of the hydrolyzate according to the invention into fish feed (salmon) a. Materials and methods

[0263] The hydrolysate described in Examples 1 and 2 is used. Commercially available 2 mm feed pellets from Skretting AS (RCX) were used as the basis for the production of two diets, detailed below. These pellets comprise, among other things, 49% by weight of protein, 22% by weight of fat and 9% by weight of ash. Based on this formulation, a test diet was formulated, in which 1% of hydrolysate was added by coating.

[0264] Finally, both diets were prepared by coating the pellets with water to balance the average water content to approximately 13% by weight of the total pellet weight.

[0265] The trials were conducted on salmon. A total of 320 Atlantic salmon with an average weight of 17g were randomly distributed into six 80L tanks (an average weight of 16.63-16.70g per tank). Each diet was fed to three overeating tanks.

[0266] The experiment was conducted for 3 weeks.

[0267] Growth Assessment

[0268] All fish were weighed individually at the start of the experiment and at harvest (end of the experiment).

[0269] Fecal assessment

[0270] At the end of the experiment, 10 fish per tank were randomly selected for fecal appearance.

[0271] The consistency of the feces was analyzed visually and evaluated according to a scale ranging from 1 to 4, where score 1: solid and firm, score 2: semi-solid, soft digestate, score 3: diarrhea, runny digestate, score 4: yellow or non-white casts of non-food matter / no digestate.

[0272] Digestate corresponds to the residual material resulting from methanization (anaerobic digestion). b. Results

[0273] Growth Assessment

[0274] Body weight increased 2.2 times during the experimental period, from 17 g to 38.5-39.5 g, corresponding to a growth rate (SGR) of 3.48-3.58. As highlighted in Figure 2, slaughter yield was significantly lower for the control (82.7%) compared to the diet containing the hydrolysate (83.7%).

[0275] Fecal assessment

[0276] The softest consistency is observed for the CTRL group (Table 11, Figure 3, left stick).

[0277] [Table 11]

[0278] *By “Hydrolyzate” we mean the diet comprising the hydrolyzate according to the invention.

[0279] Table 11: Average fecal score.

[0280] As can be seen in Figure 3 and Table 11, the inclusion of a hydrolysate in the salmon diet significantly improved the consistency of feces compared to the control diet. Indeed, compared to the control diet, the diet containing the T. molitora hydrolysate improved the proportion of solid feces (score 1), between 70% and 80% respectively, compared to 40% for the control diet.

[0281] The lower incidence of semi-solid stools makes the hydrolyzate according to the invention interesting in animal feed supplementation, particularly for application in aquaculture, which requires high water quality to avoid damaging the biofilters.

[0282] The experimental data generated in this example make it possible to affirm that supplementation in animal feed with the hydrolyzate according to the invention significantly improves the consistency of the feces.

[0283] Example 5: Introduction of the hydrolyzate according to the invention into fish feed (salmon) a. Material and method

[0284] The process described in Example 1 was reproduced and made it possible to obtain a hydrolyzate with the following characteristics:

[0285] Table 12: Composition of the hydrolysate A control diet (CTRL2) was formulated with ingredients meeting the known nutritional needs of salmon. Based on this diet, another diet including the hydrolysate described in Table 12 was produced (see Table 13 below). *% of dry matter in relation to the total weight of the composition

[0286] 1 Fish meal: from Pelagia Norway, reference: PA / ES / 21 / 003, comprising 70.5% crude protein and 9.4% crude fat.

[0287] 2 Premix: This is a premix of vitamins and minerals including the following ingredients:

[0288] Vitamin A 500,000 IU; Vitamin D3 300,000 Ul; Vitamin E 40,000 Ul; Vitamin K3 2,000 mg; Vitamin B1 3,000 mg; Vitamin B2 5,000 mg; Calcium D-pantothenate 8 OOOmg; Niacinamide 15,000 mg; Vitamin B6 3,000 mg; Folic acid 1,000 mg; Vitamin B12 5,000 mg; Vitamin C 25,000 mg; Biotin 55,000 mg; calcium iodate, anhydrous, iodine 600.0 mg; manganese oxide, manganese 3,000.0 mg; zinc oxide, zinc 21000.0 mg.

[0289] Table 13: Composition of experimental diets

[0290] The diets detailed in Table 12 were manufactured by extrusion using standard techniques known to those skilled in the art so as to obtain granules having a size of 2 mm.

[0291] The pellets are obtained by first mixing soy protein concentrate, fish meal, wheat gluten, potato starch, pemix, lysine, methionine, monocalcium phosphate, ytrium oxide, choline chloride according to the contents indicated in Table 13, in a Spiry 25 dough mixer. In a second step, fish oil and hydrolyzate (for the diet according to the invention) were added to the mixture. In a third step, gelatin activated at 60°C was also added to the mixture. The dough thus obtained was transformed into pellets, cold, using an extruder. The pellets were dried at 45°C until a dry matter content of approximately 93% was obtained.

[0292] Thus, in this embodiment, the hydrolyzate is mixed with the other ingredients constituting the food (granule) before extrusion.

[0293] Each diet was tested in triplicate (3 tanks per diet). 180 Atlantic salmon with an average weight of 20.3 ± 0.3 g were randomly distributed in each tank (6 tanks with a volume of 80 L each). The tanks are connected to a recirculating aquaculture system (RAS). The tanks are supplied with fresh water at a water temperature between 13.3 and 15.3 °C (with an average temperature of 14.1 °C).

[0294] Each diet was fed in excess appetite and uneaten food was collected to accurately calculate the feed conversion rate (RCA).

[0295] 10 salmon per tank were selected to evaluate their growth performance. After 58 days of experimental feeding, these 10 salmon were euthanized by anesthetic overdose. b. Results

[0296] Growth Assessment

[0297] The 10 selected salmon were weighed at the beginning of the experiment and then at harvest (end of the experiment). Their size was measured at harvest.

[0298] *By “Hydrolysate” we mean the diet comprising the hydrolysate according to the invention Table 15: Results on the growth performance of salmon

[0299] Values ​​are expressed as mean ± standard deviation (n=3). In this case, the standard deviation is equal to the standard error.

[0300] Asterisks indicate significant differences between experimental groups and the CTRL2 control group (Student's t test, P < 0.05; n = 3).

[0301] From the results presented above, it is observed that the body weight of salmon fed with the pellets comprising the hydrolysate was multiplied by 5. In addition, it is observed that for an equivalent daily feed intake (RCA of 0.67 for the CTRL2 group and for the group fed with the diet comprising the hydrolysate), the weight and length of salmon fed with the pellets according to the invention significantly increased compared to salmon fed with the CLTRL2 pellets. Indeed, a significant difference in body weight of 14.3% was obtained (see Table 15 and Figure 4a).

[0302] Fat score around viscera and eviscerated weight

[0303] At the end of the experiment, the amount of fat around the viscera of the tested salmon was determined using a visual determination method as detailed below:

[0304] The amount of visceral fat was graded from 1 to 5 based on the visibility of the pyloric caeca (Figure 5).

[0305] - a score of 1: pyloric caeca clearly visible,

[0306] - a score of 2: visible pyloric ceca,

[0307] - a score of 3: pyloric caeca visible as cracks in the visceral fat,

[0308] - a score of 4: pyloric caeca visible through visceral fat,

[0309] - a score of 5: pyloric ceca not visible.

[0310] So, the lower the score, the less fat there is around the viscera.

[0311] In addition, the gutted weight of the salmon was also measured. The results are shown in Table 16 below.

[0312] *By “Hydrolysate” we mean the diet comprising the hydrolysate according to the invention

[0313] Table 16: Results on fat deposition around the viscera

[0314] From these results, it is observed that although there is no significant difference between salmon fed with pellets from the CTRL2 group and those fed with pellets according to the invention, the latter tend to have a higher eviscerated weight.

[0315] Furthermore, it is observed that there is no significant difference regarding the deposition of fat around the viscera.

[0316] It can therefore be concluded from all of these results that salmon fed with the pellets according to the invention exhibit significantly greater growth in terms of weight and length without becoming fat. Thus, a fish diet comprising the hydrolysate according to the invention specifically increases the growth of body muscle mass in addition to body length without causing fat accumulation around the viscera. As a result, the hydrolysate according to the invention makes it possible to considerably increase the growth of fish while maintaining them in good physical condition, and thus improves the nutritional value of fish fed with pellets comprising the hydrolysate according to the invention.

Claims

Claims 1. Hydrolyzate obtained from insects, comprising at least 50% by weight of proteins, at least 7% by weight of lipids, at least 10.5% by weight of ash, the percentages by weight being indicated on the dry weight of the hydrolyzate, and a dry matter content of between 15 and 35% by weight, the percentage being given on the weight of the hydrolyzate.

2. Hydrolyzate according to claim 1, in which the insects are beetles.

3. Hydrolyzate according to any one of the preceding claims, comprising a fiber content of between 1 and 5% by weight on the dry weight of the hydrolyzate.

4. Hydrolyzate according to any one of the preceding claims, comprising water-soluble proteins, 75% of the water-soluble proteins having a size less than 12400 g / mol, based on the total weight of water-soluble proteins.

5. Hydrolyzate according to any one of the preceding claims, comprising one or more additives chosen from a preservative and / or a pH lowerer.

6. Hydrolyzate according to any one of the preceding claims, comprising 40 to 60% by weight of insoluble proteins, the percentage by weight being expressed relative to the total weight of proteins.

7. A process for preparing a hydrolysate from insects comprising the following steps: a) Separation of the cuticles and the soft part of the insects, b) Separation of the soft part of the insects into an aqueous fraction, an oily fraction and a solid protein fraction, and c) Enzymatic hydrolysis of the solid protein fraction.

8. Method according to claim 7, further comprising a step of killing the insects, prior to the step of separating the cuticles from the soft part.

9. Method according to claim 7 or 8, further comprising a step of maturation of the soft part of the insects, between the step of separation of the cuticles of the part soft and the step of separating the soft part of the insects into an oily fraction, a solid fraction and an aqueous fraction.

10. Method according to one of claims 7 to 9, further comprising a step of stabilizing the hydrolyzed solid protein fraction obtained in step c), by adding one or more additives chosen from a preservative and / or a pH lowerer.

11. Use of the hydrolyzate according to claims 1 to 6, in an animal feed.

12. Use according to claim 11, wherein the food is in the form of granules, flakes, pâté, kibble or treats.

13. Use according to one of claims 11 or 12, in which the food comprises from 1% to 20% by weight of the hydrolyzate, the percentage by weight being indicated on the weight of the food.

14. Use according to one of claims 11 to 13, for improving the growth of farmed fish.

15. Use according to one of claims 11 to 13, for improving the consistency of feces.

16. Animal feed comprising 1 to 20% by weight of the hydrolysate according to claims 1 to 6, the percentage by weight being given on the weight of the feed.

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