Process for preparing a palatability enhancer from insects

Abstract

Process for preparing a palatability enhancer from insects The invention relates to a process for preparing a palatability enhancer from insects, to a palatability enhancer obtainable by implementing the process according to the invention, to a food comprising a palatability enhancer according to the invention and to a process for improving the palatability of a food composition comprising the incorporation of a palatability enhancer according to the invention into a food composition.

Description

Title of the invention: Process for preparing a palatability enhancer from insects Technical field

[0001] The invention relates to a method for preparing a palatability enhancer from insects. The palatability enhancer can in particular be used in industry, in particular in the agri-food industry and in animal feed. Prior art

[0002] Insects provide a nutritional contribution rich in essential nutrients and thus represent a food source of interest. The European Union has also integrated them into its regulations 68 / 2013, 2015 / 2283 and 2021 / 1372 as a new food, and considers them to be a foodstuff of the future. This alternative food is interesting in view of the agricultural and ecological challenges that populations will have to face and the shortage of land. Moreover, since the nutrients obtained from insects are rich in proteins and fats, their use would make it possible to substitute fish or soy-based feed in animal feed.

[0003] Insects are also used for the preparation of palatability agents. Mention may in particular be made of documents CN111227132, CN115088786, CN115104678 and CN109043124 which describe processes for preparing palatability compositions for pets from whole insects. However, these processes require the use of whole insects, which greatly limits the use of the insect. In particular, the protein fraction, which constitutes the most valued fraction in insects, is entirely used during the process of preparing the palatability agent. The palatability improvers obtained with such processes therefore have a high cost.

[0004] There is therefore a need to develop alternative processes to reduce the manufacturing costs of palatability enhancers produced from insects and to optimize the use of the different fractions contained in insects.

[0005] It is in this context that the Applicant has developed, and this constitutes the basis of the present invention, a process for preparing a palatability enhancer from insects comprising the steps described below. The process developed by the Applicant makes it possible in particular to better exploit the different fractions of the insect, in particular the protein fraction and the oily fraction. Summary of the invention

[0006] The present invention, which finds application in the field of food, aims to propose a new process for preparing a palatability improver from insects.

[0007] According to a first aspect, the invention relates to a method for preparing a palatability enhancer from insects, comprising the following steps: a) obtaining an oily fraction from insects, b) subjecting the oily fraction to hydrolysis in order to obtain a hydrolyzed oily fraction, c) heating the hydrolyzed oily fraction to induce a Maillard reaction.

[0008] According to a second aspect, the invention relates to a palatability improver capable of being obtained by implementing the method according to the invention.

[0009] According to a third aspect, the invention relates to a food composition comprising (i) at least one food ingredient, and (ii) a palatability enhancer according to the invention.

[0010] According to a fourth aspect, the invention relates to a method for improving the palatability of a food composition, comprising the incorporation of a palatability improver according to the invention into a food composition.

[0011] According to a fifth aspect, the invention relates to a method for improving the palatability of a food, comprising the application of a palatability improver according to the invention to a food. Detailed description

[0012] Definitions

[0013] The term "palatability enhancer" or "palatability factor" designates a compound or composition which, when added to a food, significantly increases the palatability of that food and, consequently, its consumption.

[0014] The term "insects" refers to insects at any stage of their development, such as the adult stage, the larval stage and / or the nymph stage. In the context of the present invention, the insects are preferably at the larval stage. The insects may be selected from Coleoptera, Diptera, Lepidoptera, Orthoptera, Isoptera, Hymenoptera, Blattoptera, Hemyptera, Heteroptera, Ephemeroptera and Mecoptera, preferably from Diptera. In particular embodiments, the insects are chosen from 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, Gryllodes sigillatus, Gryllus assimillis and Samia ricini, Bombyx mori, preferably chosen from Hermetia illucens, gryllodes sigillatus, Gryllus assimillis, Musca domestica, Tenebrio molitor, Alphitobius diaperinus and Acheta domesticus. The larvae of Hermetia illucens are particularly preferred in the context of the present invention.

[0015] The term "hydrolysis" refers to a chemical reaction in which a covalent bond is broken by the action of a water molecule. Hydrolysis can be carried out by the action of an enzyme, in which case we speak of enzymatic hydrolysis.

[0016] For the purposes of the invention, the term "lipid hydrolysis" or "lipolysis" designates a chemical reaction in which lipid molecules, such as triglycerides, react with water resulting in the cleavage of ester bonds. The products of this reaction are, for triglycerides, free fatty acids and glycerol. The hydrolysis of lipids can be carried out, for example, by saponification or by the action of a lipase; this is then referred to as enzymatic lipolysis.

[0017] The term "saponification" refers to a chemical reaction in which lipid molecules, such as triglycerides, react with a strong alkali, such as sodium hydroxide (NaOH), to form soap. During saponification, the ester bonds of lipids are broken, which releases, among other things, fatty acid salts (soap).

[0018] The term "lipase" refers to a class of enzymes that catalyze the hydrolysis of lipids. Lipases are found in a variety of organisms, including animals, plants, fungi, and bacteria. Lipases are highly soluble in water and act at the oil-water interface. Access to the active site is controlled by the opening of a valve that, when closed, hides the hydrophobic surface surrounding the lipase active site. The valve opens when the lipase comes into contact with an oil-water interface (interfacial activation).

[0019] The term "triacylglycerol lipase" refers to a subclass of lipases that catalyzes the hydrolysis of triglycerides, including long-chain triglycerides. Triacylglycerol lipases hydrolyze triglycerides into diglycerides, monoglycerides, and free fatty acids.

[0020] The term "Maillard reaction" refers to a set of glycation reactions between reducing sugars and compounds that carry an amine group, such as amino acids and proteins. In the food industry, the Maillard reaction generates compounds that contribute to the color, flavor, and odor of a food. They begin with a condensation between the amine group of an amino acid or protein, and the carbonyl group of reducing sugars (e.g., glucose, fructose, lactose, ribose, xylose). This first step is followed by various reactions depending on the reagents and conditions. In particular, a Maillard reaction can be induced by heating food products.

[0021] The term "animal" means any animal that may benefit from increased palatability resulting from a palatability enhancer, including humans, birds, bovines, canines, equines, felines, lupines, murines, ovines or porcines. In particular, it may be domestic animals such as cats, dogs, rabbits, guinea pigs, ferrets, hamsters, mice, gerbils, horses, cows, goats, sheep, donkeys, pigs, etc.

[0022] All percentages expressed in this description are expressed by weight over the weight of the total composition considered, including the water content ("wet weight"), unless otherwise indicated.

[0023] Process for preparing a palatability improver

[0024] According to a first aspect, the invention relates to a method for preparing a palatability enhancer from insects, comprising the following steps: a) obtaining an oily fraction from insects, b) subjecting the oily fraction to hydrolysis in order to obtain a hydrolyzed oily fraction, c) heating the hydrolyzed oily fraction to induce a Maillard reaction.

[0025] The method according to the invention makes it possible in particular to obtain a palatability improver essentially from the oily fraction, thus making it possible to furthermore use all or part of the protein fraction.

[0026] Step a)

[0027] Step a) consists of obtaining an oily fraction from insects.

[0028] In the field of preparing food products from insects, insects are generally considered to consist of two fractions, namely a solid fraction and a liquid fraction. The solid fraction, also called the "cuticle", is a chitin-rich fraction. Chitin is an amorphous solid constituting the cuticle of insects. The liquid fraction, also called the "soft part of insects", comprises the aqueous protein fraction and the oily fraction.

[0029] Obtaining an oily fraction from insects does not present any particular difficulty for the person skilled in the art. For example, an oily fraction can be obtained (i) by grinding insects and then subjecting the ground material to one or more physical separation steps which make it possible to separate the different fractions of the insect (wet process) or (ii) by pressing dehydrated insects (dry process). It is also possible to obtain the oily fraction by implementing other methods, such as the use of solvent or supercritical CO2. Obtaining an oily fraction from insects by the wet or dry process are the most used in industry.

[0030] Wet way

[0031] In a particular embodiment, the oily fraction of step a) is obtained by grinding insects and then subjecting the ground material to one or more physical separation steps which make it possible to separate the different fractions of the insect.

[0032] Grinding makes it possible to obtain a starting material of viscous consistency. The viscosity of the ground material can vary depending on the nature and composition of the ground insects. The person skilled in the art will have no difficulty in adapting the viscosity of the ground material. For example, the desired viscosity can be easily obtained by adding more or less water before, during or after grinding the insects.

[0033] The grinding can be carried out with a suitable grinding tool, for example a grinder comprising a turbine and a cutting head, a ball mill or even a micro-grinder. The choice of the grinding tool can influence the particle size of the insect particles present in the ground material. Preferably, the particle size of the insect particles present in the ground material obtained in step a) is less than 2.0 mm, in particular less than 1.0 or even less than 0.5 mm. The particle size can be measured by any suitable method, for example by sieving. The person skilled in the art will have no difficulty in adapting the grinding step to obtain the desired particle size.

[0034] The grinding can be carried out at a temperature ranging from 20 to 90°C, for example at a temperature of 40 to 70°C.

[0035] Physical separation can be achieved by decantation, pressing, centrifugation, reverse osmosis separation, ultrafiltration, supercritical CO2 extraction, or a combination of several of these separation methods.

[0036] In particular, the physical separation can be carried out with an apparatus allowing simultaneous centrifugation and decanting, for example with a plate separator or with a 3-phase decanter. Such apparatuses are commonly used in the food industry to obtain in a single step an aqueous fraction (e.g. an aqueous protein fraction) and an oily fraction, while eliminating solid residues.

[0037] 3-phase decanters or "three-phase decanters" are used for the simultaneous separation of two liquid phases of different densities and one solid phase. 3-phase decanters thus perform a three-phase separation (solid-liquid-liquid separation) of dispersions of solid residues and two immiscible liquids of different densities (e.g. oil fraction and aqueous protein fraction). Several 3-phase decanters are available on the market, for example the Tricanter Flottweg 3-phase decanter, the GEA 3-phase decanter or the Andritz 3-phase decanter.

[0038] Plate separators are also known as "clarifying separators" or "plate centrifuges". These are high-speed centrifuges used for the clarification of suspensions and / or the separation of two liquids of different densities (e.g. oil fraction and aqueous protein fraction). They operate at higher speeds than 3-phase decanters. Several plate separators are available on the market, for example the Flottweg plate separator, the GEA plate separator or the Alfa Laval plate separator.

[0039] Physical separation makes it possible to eliminate the solid residues present in the liquid fraction. The insect ground material can therefore be subjected to physical separation in order to obtain an aqueous protein fraction, an oily fraction, and a solid residue fraction (fraction commonly called "settling" or "centrifugation sludge").

[0040] The physical separation can be carried out at a temperature ranging from 45°C to 90°C. The physical separation can also be carried out at lower temperatures, for example at a temperature ranging from 50 to 80°C, in particular at a temperature ranging from 65 to 75°C.

[0041] In a first particular embodiment, the oily fraction of step a) is obtained by implementing a method comprising the following steps: a1) grinding insects in order to obtain a ground material, a2) optionally, subjecting the ground material to enzymatic hydrolysis with a protease in order to obtain a hydrolyzed ground material, a3) optionally, pressing the ground material or the hydrolyzed ground material in order to obtain a solid fraction enriched in chitin and a liquid fraction, and a4) subjecting the ground material, the hydrolyzed ground material or the liquid fraction to a physical separation in order to extract an oily fraction.

[0042] The grinding steps a1) and physical separation a4) can be implemented as detailed above.

[0043] The insects ground in step a1) may be insects which have not been subjected to any treatment or which have undergone a slaughter step. The slaughter may advantageously be carried out by thermal shock, for example by scalding or by freezing.

[0044] The insects ground in step a1) may also be insects that have previously been dehydrated. Grinding therefore makes it possible to obtain an insect powder. It is understood that the insect powder must be rehydrated if optional steps a2) and / or a3 are implemented. The insect powder may nevertheless be directly subjected to a step a4) of physical separation by pressing to extract the oily fraction, as explained below.

[0045] In general, the smaller the particle size in step a1), the easier the hydrolysis of the optional step a2). A small particle size promotes enzymatic attack and thus increases the performance of enzymatic hydrolysis.

[0046] Optional step a2) is carried out by bringing the ground material obtained in step a1) into contact with one or more protease enzymes. The protease(s) may be acidic, basic or neutral protease(s), for example chosen from aminopeptidases, metallocarboxypeptidases, serine endopeptidases, cysteine ​​endopeptidases, aspartic endopeptidases, metalloendopeptidases, exopeptidases or a mixture thereof.

[0047] The following enzymes, or a mixture of several of these enzymes, can be used in step a2): - Bacillus protease: Protamex (EC 3.4.21.14, Novozyme), - Casein protease: Promod 439L (Biocatalysts), - Aminopeptidases : Flavourzyme (EC 3.4.11.1, Novozyme), Fungal protease 500 (EC 3.4.11.1, Bio-Cat), Kojizyme (EC 3.4.11.1, Novozyme), - Endopeptidases sérine : Protex P (EC 3.4.21, Genencor International B.V.), Chymotrypsine (EC 3.4.21.1 Novozyme), Protamex (EC 3.4.21, Novozyme), Elastase (EC 3.4.21.14, Novozyme), Trypsine (EC 3.4.21.36, Novozyme), Alcalase (EC 3.4.21.4, Novozyme), - Endopeptidases cystéine : Papaïne (EC 3.4.22, BSC Biochemicals), Bromelaine (ananase) (EC 3.4.22.32, Bio-Cat), - Endopeptidases aspartique : Prolyve NP (EC 3.4.23, Lyven), Pepsine (EC 3.4.24.1, Sigma Aldrich), - Métallo-endopeptidases : Neutral protéase (EC 3.4.24.28, Bio-Cat), - Endopeptidases : Protex 50 FP (EC 3.4.21, Genencor International B.V. (Dupont)), Sumizyme BNP-L (Takabio-Shin Nihon), - Exo and endopeptidase (protease + amylase cocktail): Pancrealyve (Lyven), - Aspartic protease: Izyme BA (EC 3.4.23, Novozyme), - Aspergillopepsin I: Sumizyme AP-L (Takabio-Shin Nihon), - Zn-based endoprotease of beta ayloliequefaciens: Neutrase (EC 3.4.24, Novozyme), and - Protease: Novozyme 37071 (Novozyme).

[0048] The amount of enzyme(s) added in step a2) can be easily adjusted depending on the enzyme(s) used in order to obtain satisfactory enzymatic activity.

[0049] The pH of the ground material may be adjusted depending on the enzyme(s) used. For acid proteases the pH will be acidic, generally ranging from pH 3 to pH 6. For alkaline proteases the pH will be basic, generally ranging from pH 8 to pH 10. For neutral proteases the pH will be neutral, generally ranging from pH 6 to pH 8.

[0050] The temperature during step a2) may be adjusted depending on the enzyme(s) used and the desired reaction rate. In one embodiment in particular, step a2) is carried out at a temperature ranging from 40 to 70°C, for example from 50 to 55°C.

[0051] Preferably, step a2) is carried out with stirring, for example by placing the ground material in a tank which comprises a device for stirring the ground material. Stirring can be facilitated by adding water to the mixture, which reduces the viscosity, and / or by using a centrifugal pump. Stirring makes it possible to homogenize the mixture and promotes enzymatic hydrolysis, which in particular makes it possible to reduce the hydrolysis time.

[0052] In a particular embodiment, the hydrolysis reaction is stopped by heating the hydrolyzed ground material, in particular at a temperature ranging from 70 to 100°C, for example by heating to 80°C. Heating makes it possible to inactivate the protease. Typically, hydrolysis stops after 1 to 5 hours, for example after 3 to 4 hours.

[0053] In another particular embodiment, the hydrolyzed ground material is not heated to stop the hydrolysis reaction before step a3) or a4). The fact of not heating the hydrolyzed ground material makes it possible to preserve the hydrolyzed ground material from degradation by heat, in particular of the lipids contained in the ground material. This embodiment makes it possible to preserve the quality of the fractions obtained in step a4), in particular the oily fraction.

[0054] Optional step a3) consists of pressing the ground material or the hydrolyzed ground material in order to obtain a solid fraction enriched in chitin and a liquid fraction.

[0055] The solid fraction enriched in chitin corresponds to the fraction commonly called "press cake" or "sludge" and the liquid fraction corresponds to the fraction commonly called "press juice" or "filtrate". The pressing can be carried out with a suitable pressing tool, for example a screw press.

[0056] The temperature during pressing must be high enough so that the lipids present in the ground material or hydrolyzed ground material (oily fraction) are in the liquid state. The temperature during pressing is generally above 25°C, for example between 25°C and 100°C, between 40°C and 100°C, between 60°C and 100°C, or between 80 and 90°C. The choice of temperature may depend on the nature of the lipids present in the ground material or hydrolyzed ground material.

[0057] Advantageously, the pressing tool is equipped with a sieve. The sieve makes it possible to retain the solid fraction enriched in chitin while allowing the liquid fraction to pass through. The pore size is preferably less than 3 mm, for example from 0.5 to 2 mm.

[0058] When pressing is carried out with a screw press equipped with a screen, the person skilled in the art has no difficulty in choosing a suitable screen and adjusting the pressure, for example by adjusting the speed of the screw and the closing of the shutter. In general, the pressure applied with a screw press ranges from 1 to 5 bar(s). The use of a press screw is particularly advantageous since it allows the chitin-enriched solid fraction and the liquid fraction to be separated efficiently at a low rotation speed (less than 50 revolutions per minute) compared to the rotation speed of decanters (generally between 3000 and 4000 revolutions per minute), which avoids the formation of an emulsion.

[0059] Step a3) makes it possible in particular to obtain a press juice essentially free of solid elements, in particular essentially free of chitin. Pressing considerably facilitates the implementation of the subsequent steps implemented from the press juice, in particular step a4) of physical separation. Thus, when step a3) is implemented, the liquid fraction is transformed in step a4) to obtain in particular aqueous and oily protein fractions.

[0060] Dry route

[0061] In another particular embodiment, the oily fraction of step a) is obtained by implementing a method comprising the following steps: a1') obtaining dehydrated insects, and a2') pressing the dehydrated insects in order to extract an oily fraction.

[0062] The dehydrated insects obtained in step a1') may be whole or ground insects, as described above. The dehydration may be total or partial. Preferably the dehydrated insects comprise less than 10% by weight of water relative to the total weight of the insect, for example less than 5%, such as less than 3%.

[0063] The insects used to obtain the dehydrated insects of step a1') may be insects which have not been subjected to any treatment or which have undergone a slaughter step. The slaughter may advantageously be carried out by thermal shock, for example by scalding or by freezing.

[0064] Step a2') consists of pressing the dehydrated insects in order to directly extract an oily fraction.

[0065] The temperature during pressing must be high enough so that the lipids present in the insects are in a liquid state. The temperature during pressing is generally above 25°C, for example between 25°C and 100°C, between 40°C and 100°C, between 40°C and 60°C, between 60°C and 100°C, or between 80 and 90°C. The temperature during pressing is commonly around 50°C.

[0066] Advantageously, the pressing tool is equipped with a sieve. The sieve makes it possible to retain the solid fraction enriched in chitin and proteins while allowing the oily fraction to pass through. The pore size is preferably less than 3 mm, for example 0.5 to 2 mm.

[0067] When the pressing is carried out with a screw press equipped with a screen, the person skilled in the art has no difficulty in choosing a suitable screen and in adjusting the pressure, for example by adjusting the speed of the screw and the closing of the shutter. In general, the pressure applied with a screw press is greater than 3 bar, for example it is greater than 5 bar. The pressure applied can range from 1 to 10 bar(s), for example it ranges from 1 to 5 bar(s).

[0068] Step a2') makes it possible in particular to directly obtain an oily fraction essentially freed from solid elements.

[0069] The oily fraction directly obtained after step a2') can be purified, for example by placing it in a settling tank.

[0070] Preferably, the oily fraction obtained in step a) of the process according to the invention has a lipid content greater than or equal to 80% by weight (wt%) relative to the total weight of the oily fraction, for example greater than or equal to 85 wt%, greater than or equal to 90 wt%, greater than or equal to 95 wt%, greater than or equal to 96 wt%, greater than or equal to 97 wt%, greater than or equal to 98 wt%, for example greater than or equal to 99 wt% by weight relative to the total weight of the oily fraction.

[0071] Step b)

[0072] Step b) consists of subjecting the oily fraction to hydrolysis in order to obtain a hydrolyzed oily fraction.

[0073] The oily fraction may be premixed with water to obtain an emulsion. Water may be mixed with the oily fraction in an amount such that the emulsion comprises at least 5 wt% relative to the total weight of the emulsion, such as at least 6 wt%, for example from 10 wt% to 85 wt% of water, for example from 25 wt% to 5 wt%, such as from 30 wt% to 85 wt%, from 40 wt% to 85 wt%, from 45 wt% to 85 wt%, from 50 wt% to 85 wt% or from 60 wt% to 85 wt% relative to the total weight of the emulsion. The water added to the oily fraction allows the hydrolysis reaction to take place, the water acting as a reactant.

[0074] In a particular reaction mode, the oil:water mass ratio in the emulsion ranges from 1:5 to 5:1, for example it ranges from 2:5 to 3:2. Adjusting the oil:water mass ratio, for example depending on the enzyme used and / or the salinity, presents no difficulty for the person skilled in the art.

[0075] Thus, in a particular embodiment, step b) consists of: bl) mixing the oily fraction with water to obtain an emulsion, and b2) subjecting the emulsion to hydrolysis in order to obtain a hydrolyzed oily fraction.

[0076] The emulsion can be obtained by stirring the oil fraction / water mixture. For example, the oil fraction / water mixture can be stirred vigorously for a few minutes to obtain an emulsion. The homogeneity of the emulsion can then be maintained by adjusting the stirring, the aim being to avoid phase separation. A homogeneous emulsion makes it possible in particular to maximize the surface area of ​​the oil / water interface. water, which enhances the hydrolysis reaction. Optionally, an emulsifier can be added to the mixture to facilitate and / or stabilize the emulsion.

[0077] Advantageously, the water added to the oily fraction contains salts, such as NaCl and CaCl2. The salts make it possible in particular to improve the efficiency of step b) when step b) is carried out with an enzyme (see below), and therefore to increase the hydrolysis rate. However, the salinity must not be too high to avoid negatively impacting the functioning of the enzyme and / or to avoid denaturing the homogeneity of the hydrolyzed product. The person skilled in the art will be able to easily adapt the salinity of the water to optimize the efficiency of the enzyme while preserving the homogeneity of the hydrolyzate.

[0078] The temperature during step b) may be adjusted so that the oily fraction is in liquid form. In a particular embodiment, step b) is carried out at a temperature ranging from 40 to 70°C, for example from 50 to 55°C.

[0079] In particular embodiments, one or more compounds chosen from (i) one or more amino acids, (ii) proteins and (iii) one or more sugars are added to the oily fraction. Advantageously, (i) one or more amino acids are added in an amount ranging from 0.01 wt% to 80 wt% relative to the total weight of the oily fraction, preferably from 0.1 wt% to 25 wt%, for example from 0.5 wt% to 5 wt%; and / or (ii) one or more sugars are added in an amount ranging from 0.01 wt% to 80 wt% relative to the total weight of the oily fraction, preferably 0.1 wt% to 25 wt%, for example from 0.5 wt% to 5 wt% relative to the total weight of the oily fraction.

[0080] In particular embodiments, step b) consists of subjecting the oily fraction to (i) enzymatic hydrolysis, preferably with one or more lipase(s), and / or (ii) saponification in order to obtain a hydrolyzed oily fraction.

[0081] Enzymatic hydrolysis

[0082] In particular embodiments, step b) may be carried out by bringing the oily fraction (or the emulsion) into contact with one or more lipase-type enzymes. The lipases that may be used in the context of the present invention may be of animal origin, of plant origin or of microbial origin (fungi, yeasts or bacteria). It is understood that the term “oily fraction” may be substituted hereinafter by the term “emulsion” when the oily fraction is mixed with water to obtain an emulsion (see the embodiment described above).

[0083] Lipases of animal origin can be used in the food industry and can, for example, be pregastric lipases, pancreatic lipases, hepatic lipases, etc.

[0084] Lipases of microbial origin are produced by fungi, yeasts and bacteria. The following microorganisms account for the majority of industrial production of microbial lipases: Candida sp., Aspergillus sp., Rhizomucor sp., Rhizopus sp., Humicola sp., Yarrowia lipolytica and Pseudomonas sp. They are developed, produced and marketed by major players in the enzyme sector for different applications.

[0085] Enzymes belonging to the following enzyme classes can be used in step b): - EC 3.1.1.3: triacylglycerol lipase, - EC 3.1.1.4: phospholipase A2, - EC 3.1.1.5: lysophospholipase, - EC 3.1.1.23: acylglycerol lipase, - EC 3.1.1.26: galactolipase, - EC 3.1.1.32: phospholipase Al, - EC 3.1.1.34: lipoprotein lipase, - EC 3.1.1.79: hormone-sensitive lipase, - EC 3.1.1.116: sn-l-specific diacylglycerol lipase, - EC 3.1.1.118: phospholipid sn-1 acylhydrolase, - EC 3.1.4.3: phospholipase C, - EC 3.1.4.4: phospholipase D, - EC 3.1.4.11: phosphoinositide phospholipase C, - EC 3.1.4.50: glycosylphosphatidylinositol phospholipase D, and - EC 3.1.4.54: N-acetylphosphatidylethanolamine-hydrolysing phospholipase D.

[0086] Examples of commercially sold lipases for food applications are described below: - lipases marketed by Novozyme: Lecitase® Ultra 10L (pancreatic phospholipase A2), Lecitase® (microbial phospholipase Al), Lecitase® Ultra (thermostable microbial phospholipase Al), - lipases marketed by AB Enzymes: Rohalase® MPL (phospholipase A2), Rohalase® PL-Xtra (phospholipase A2), - lipases marketed by DSM: Purifine® DLC (phospholipase C), Purifine® 3G (combination of several phospholipases), Gumzyme® (phospholipase A2), - lipases marketed by Danisco: Lysomax® (phospholipase A2), - lipases marketed by Sigma-Aldrich: L3126-25G (triacylglycerol lipase), - triacylglycerol lipases with the following CAS numbers: NO: 9001-62-1, NO: 9004-02-8, NO: 9001-62-1.

[0087] In particular embodiments, the lipase is of animal origin.

[0088] In particular embodiments, the lipase is one or more phospholipases, for example chosen from phospholipase A1, phospholipase A2 and phospholipase C. The phospholipases used in the food industry are often of microbial origin (Trichoderma, Aspergillus, Pichia, etc.) or derived from pig pancreas. The main suppliers of phospholipases are Novozymes, DSM, Dupont, AB Enzymes.

[0089] In other particular embodiments, the lipase is one or more lipases selected from acylglycerol lipases (EC 3.1.1.23, EC 3.1.1.118), diacylglycerol lipases (EC 3.1.1.116) and triacylglycerol lipases (EC 3.1.1.3).

[0090] In a preferred embodiment, the lipase is a triacylglycerol lipase (EC 3.1.1.3).

[0091] The amount of enzyme(s) added in step b) can be easily adjusted depending on the enzyme(s) used in order to obtain satisfactory enzymatic activity.

[0092] The pH of the oily fraction may be adjusted depending on the enzyme(s) used, for example according to the supplier's recommendations.

[0093] The temperature during step b) may be adjusted depending on the enzyme(s) used and the desired reaction rate. In a particular embodiment, step b) is carried out at a temperature ranging from 40 to 70°C, for example from 50 to 55°C.

[0094] Preferably, step b) is carried out with stirring, for example by placing the oily fraction in a tank which comprises a device for stirring the oily fraction. Stirring promotes enzymatic hydrolysis, which in particular makes it possible to reduce the hydrolysis time.

[0095] Enzymatic hydrolysis generally lasts from 1 to 5 hours, for example from 3 to 4 hours. Thus, all or part of the lipids are hydrolyzed by the action of lipase. Advantageously, at least 10% by weight of the lipids (wt%) are hydrolyzed, for example at least 15 wt% of the lipids are hydrolyzed, for example at least 20 wt% of the lipids are hydrolyzed, for example at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 45 wt%, at least 50 wt%, at least 55 wt%, at least 60 wt%, at least 65 wt%, at least 70 wt%, at least 75 wt%, at least 80 wt% or at least 85 wt% of the lipids are hydrolyzed. The percentage of hydrolyzed lipids can be measured by measuring the acid number (AI), for example according to the NF EN ISO 660 standard, or by gas chromatography (GC), for example according to the IUPAC 2-323 standard or the ISO / CD 17383 standard.CPG allows, through retention times, to determine the presence of triglycerides (TGs), diglycerides (DGs), monoglycerides (MGs) and free fatty acids (FFAs).

[0096] The use of a lipase to carry out step b) is also advantageous since the lipase can constitute a reagent for the Maillard reaction during step c).

[0097] Saponification

[0098] In particular embodiments, step b) can be carried out by saponification.

[0099] Saponification is a chemical reaction between a strong base and a fatty substance (glycerol ester). It produces soaps (a fatty acid salt) and releases glycerol. Saponification can be carried out using strong bases, such as NaOH or KOH.

[0100] Carrying out saponification presents no difficulty for the person skilled in the art. It may consist simply of mixing the strong base with the oily fraction in suitable proportions. The quantity and concentration of the strong base added to the oily fraction can be adapted without difficulty by the person skilled in the art. However, it is preferable that the quantity and concentration of the strong base are adapted so that the hydrolyzed oily fraction remains in liquid form. Indeed, the addition of a large quantity of strong base to the oily fraction, in particular a concentrated strong base, can produce a hydrolyzed oily fraction in solid form, which is not desirable.

[0101] The temperature during step b) may be adjusted depending on the amount of strong base added, the concentration of the strong base and the desired reaction rate. In a particular embodiment, step b) is carried out at a temperature ranging from 40 to 75°C, for example from 50 to 70°C.

[0102] Preferably, step b) is carried out with stirring, for example by placing the oily fraction in a tank which comprises a device for stirring the oily fraction. Stirring promotes saponification, which in particular makes it possible to reduce the hydrolysis time.

[0103] It is also possible to add an emulsifier during saponification, for example lecithin.

[0104] Saponification generally lasts from 2 to 3 hours. Thus, all or part of the lipids are hydrolyzed during saponification. Advantageously, at least 20% by weight of the lipids (wt%) are hydrolyzed, for example at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 45 wt%, at least 50 wt%, at least 55 wt%, at least 60 wt%, at least 65 wt%, at least 70 wt%, at least 75 wt%, at least 80 wt% or at least 85 wt% of the lipids are hydrolyzed. The percentage of hydrolyzed lipids can be measured by the acid-base assay method using the colored indicator phenolphthalein or by a gas chromatography (GC) method. The CPG allows, through retention times, to determine the presence of triglycerides (TGs), diglycerides (DGs), monoglycerides (MGs) and free fatty acids (FFAs).

[0105] Enzymatic hydrolysis + saponification

[0106] In particular embodiments, step b) can be carried out by bringing the oily fraction into contact with one or more lipase-type enzymes and saponification.

[0107] Contacting the oily fraction with one or more enzymes can be carried out as described above.

[0108] Saponification can be carried out as described above.

[0109] Advantageously, the contacting of the oily fraction with one or more lipase-type enzymes is carried out before saponification.

[0110] Step c)

[0111] Step c) consists of heating the hydrolyzed oily fraction to induce a Maillard reaction.

[0112] In particular embodiments, one or more compounds chosen from (i) one or more amino acids, (ii) proteins and (iii) one or more sugars are added to the hydrolyzed oily fraction.

[0113] In particular embodiments, the following are added to the hydrolyzed oily fraction: - one or more sugars, and - one or more compounds chosen from (i) one or more amino acids, and (ii) proteins.

[0114] In a particular embodiment, step c) can be broken down as follows: cl) adding to the hydrolyzed oily fraction one or more sugars, and one or more compounds chosen from (i) one or more amino acids, and (ii) proteins; and c2) heating the mixture obtained at the end of step cl) to induce a Maillard reaction.

[0115] Any sugar that can be consumed during a Maillard reaction can be added to the hydrolyzed oil fraction. Examples include reducing sugars. These may be one or more monosaccharides, for example, one or more monosaccharides selected from the group consisting of glucose, fructose, galactose, ribose, xylose, arabinose, and mannose. They may also be one or more disaccharides, for example, one or more disaccharides selected from the group consisting of lactose, sucrose, maltose, trehalose, isomaltulose, lactulose. For example, they may be a mixture of lactose and xylose or a mixture of sucrose and fructose. Combined with amino acids, the lactose and xylose mixture has an ability to develop a meat-like odor in Maillard reactions, one of the favorite odors of pets.

[0116] In particular embodiments, one or more sugars are added in an amount ranging from 0.01 wt% to 80 wt% relative to the total weight of the oily fraction, preferably 0.1 wt% to 25 wt%, for example from 0.5 wt% to 10 wt%, for example from 0.5 wt% to 5 wt% relative to the total weight of the oily fraction.

[0117] Any amino acid that can be consumed during a Maillard reaction can be added to the hydrolyzed oil fraction. It can be one or more amino acids selected from the group consisting of (but not limited to): Alanine, Arginine, Asparagine, Aspartate (aspartic acid), Cysteine, Glutamine, Glutamate (glutamic acid), Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Proline, Serine, Threonine, Tryptophan, Tyrosine, Valine, Glycine. For example, it can be a mixture of Cysteine ​​and Methionine. The mixture of cysteine ​​and methionine has the ability to develop a meat-like odor in Maillard reactions, one of the favorite odors of pets.

[0118] In particular embodiments, one or more amino acids are added in an amount ranging from 0.01 wt% to 80 wt% relative to the total weight of the oily fraction, preferably from 0.1 wt% to 25 wt%, for example from 0.5 wt% to 10 wt%, for example from 0.5 wt% to 5 wt% relative to the total weight of the oily fraction.

[0119] Any protein capable of reacting in a Maillard reaction may be added to the hydrolyzed oil fraction. In a particular embodiment, proteins extracted from insects may be added to the hydrolyzed oil fraction.

[0120] In particular embodiments, proteins are added in an amount ranging from 0.01 wt% to 80 wt% relative to the total weight of the oil fraction, preferably from 0.1 wt% to 25 wt%, for example from 0.5 wt% to 10 wt%, for example from 0.5 wt% to 5 wt% relative to the total weight of the oil fraction.

[0121] In particular embodiments, the following are added to step cl): - one or more sugars as defined above in an amount ranging from 0.01 wt% to 80 wt% relative to the total weight of the oily fraction, preferably 0.1 wt% to 25 wt%, for example from 0.5 wt% to 10 wt%, for example from 0.5 wt% to 5 wt% relative to the total weight of the oily fraction; and - one or more compounds chosen from (i) one or more amino acids in an amount ranging from 0.01 wt% to 80 wt% relative to the total weight of the oily fraction, preferably from 0.1 wt% to 25 wt%, for example from 0.5 wt% to 10 wt%, for example from 0.5 wt% to 5 wt% relative to the total weight of the oily fraction and (ii) proteins added in an amount ranging from 0.01 wt% to 80 wt% relative to the total weight of the oily fraction, preferably from 0.1 wt% to 25 wt%, for example 0.5 wt% to 10 wt%, for example 0.5 wt% to 5 wt% based on the total weight of the oil fraction.

[0122] In a particular embodiment, step c) or c2) consists of heating the hydrolyzed oily fraction obtained at the end of step b) or c1) to a temperature between 60°C and 180°C, preferably between 80°C and 100°C. These temperature ranges are conventionally used to induce a Maillard reaction.

[0123] The Maillard reaction generally occurs at a pH between 4 and 8.5, preferably at pH 7. Therefore, it is preferable to maintain the pH of the heated mixture in the desired pH range, especially between pH 6 and pH 8, for example at pH 7. It should be noted, for example, that the addition of one or more amino acids may result in a decrease in the pH of the hydrolyzed oil fraction. Therefore, when adding one or more amino acids to the hydrolyzed oil fraction, it is preferable to adjust the pH to the desired pH range, for example to pH 7 for the Maillard reaction to proceed properly. To maintain the pH in the desired pH range, for example, a base, such as NaOH, may be added, preferably before heating to induce the Maillard reaction.

[0124] The heating time will be adapted according to the needs and / or taking into account other parameters such as the heating temperature. In a particular embodiment, step c) or c2) consists of heating the hydrolyzed oily fraction for a time ranging from 5 minutes to 360 minutes, preferably ranging from 60 minutes to 180 minutes, for example for 120 minutes.

[0125] In a particular embodiment, step c) consists of: - heating the hydrolyzed oily fraction to a temperature between 60°C and 180°C, preferably for a period of time ranging from 5 minutes to 360 minutes, or - heating the hydrolyzed oily fraction for a period of time ranging from 5 minutes to 360 minutes, preferably at a temperature between 60°C and 180°C.

[0126] When adding the sugar to the oil fraction, the oil fraction is preferably heated until the sugar is completely consumed during the Maillard reaction. The sugar consumption can be measured by the method described in Regulation (EC) 152 / 2009, III, J 2009-01.

[0127] The humidity level is advantageously adjusted for the implementation of step c). In particular embodiments, the humidity level of the hydrolyzed oily fraction is adjusted between 60% and 90% before step c), for example the humidity level is adjusted from 60% to 85%, from 60% to 80%, from 60% to 75%, in particular from 60 to 70%, for example to 65%, before step c). The humidity level is adjusted by adding water to the hydrolyzed oily fraction.

[0128] Preferably, step c) is carried out with stirring, for example by placing the hydrolyzed oily fraction in a heating tank which comprises a device allowing the hydrolyzed oily fraction to be stirred and heated. Stirring promotes the Maillard reaction, which in particular reduces heating time.

[0129] The palatability enhancer obtained at the end of step c) can be used directly. One or more compounds chosen from a preservative, an antioxidant (e.g. potassium sorbate, ascorbic acid, tocopherol) and a texturizing agent (e.g. xanthan gum, guar gum, agar agar) can also be added thereto. The palatability enhancer obtained in step c) can be mixed with food compositions. In general, the mixture obtained in step c) is cooled before addition to food compositions. The pH of the palatability enhancer obtained in step c) can also be lowered to an acidic pH, for example to pH 3, to help preserve it.

[0130] Other objects according to the invention

[0131] According to a second aspect, the invention relates to a palatability enhancer capable of being obtained by implementing the method according to the invention. The weight of lipids contained in the palatability enhancer is greater than the weight of proteins.

[0132] In particular embodiments, the palatability enhancer comprises at least 20 wt% of lipids relative to the total weight of the palatability enhancer, for example at least 21 wt%, at least 22 wt%, at least 23 wt%, at least 24 wt% or at least 25 wt% of lipids relative to the total weight of the palatability enhancer. For example, the palatability enhancer comprises from 20 wt% to 40 wt% of lipids relative to the total weight of the palatability enhancer, such as from 20 wt% to 30 wt%, from 22 wt% to 28 wt%, or from 24 wt% to 27 wt% of lipids relative to the total weight of the palatability enhancer.

[0133] In particular embodiments, the palatability enhancer comprises less than 10 wt% of protein relative to the total weight of the palatability enhancer, for example less than 9 wt%, less than 8 wt%, less than 7 wt%, less than 6 wt%, or less than 5 wt% of protein relative to the total weight of the palatability enhancer. For example, the palatability enhancer comprises from 1 wt% to 10 wt% of protein relative to the total weight of the palatability enhancer, such as from 1 wt% to 5 wt% of protein relative to the total weight of the palatability enhancer.

[0134] In particular embodiments, the protein:lipid mass ratio in the palatability enhancer according to the invention is greater than or equal to 1:2, for example it ranges from 1:2 to 1:15, from 1:5 to 1:15, from 1:8 to 1:12, for example it is 1:8, 1:9, 1:10, 1:11 or 1:12.

[0135] In particular embodiments, the palatability enhancer comprises more than 35 wt% of fatty acids in free form relative to the total weight of lipids, for example more than 40 wt%, more than 45 wt%, more than 50 wt%, more than 55 wt%, more than 60 wt%, more than 65 wt%, more than 70 wt% or more than 75 wt% of free fatty acids based on the total weight of lipids. For example, from 50 wt% to 95 wt% of free fatty acids based on the total weight of lipids, such as from 60 wt% to 85 wt% or from 70 wt% to 80 wt% of free fatty acids based on the total weight of lipids. The content of free fatty acids may be measured according to VDLUFAIII, 5.2.1: 1976.

[0136] According to a third aspect, the invention relates to a food, in particular a food for domestic animals, comprising (i) at least one food ingredient, and (ii) a palatability improver according to the invention.

[0137] In a particular embodiment, the food according to the invention comprises from 0.1 wt% to 20 wt% of palatability enhancer according to the invention relative to the total weight of the food, for example from 0.1 wt% to 15 wt%, from 0.1 wt% to 10 wt%, from 0.1 wt% to 5 wt%, such as from 0.5 wt% to 20 wt%, from 0.5 wt% to 15 wt%, from 0.5 wt% to 10 wt%, from 0.5 wt% to 5 wt%, for example from 1 wt% to 20 wt%, from 1 wt% to 15 wt%, from 1 wt% to 10 wt% or from 1 wt% to 5 wt% of palatability enhancer according to the invention relative to the total weight of the food.

[0138] According to a fourth aspect, the invention relates to a method for improving the palatability of a food composition, in particular a food composition for pets, comprising the incorporation of a palatability improver according to the invention into a food composition.

[0139] According to a fifth aspect, the invention relates to a method for improving the palatability of a food, in particular a pet food, comprising the application of a palatability improver according to the invention to a food.

[0140] The Applicant has in fact shown that the palatability enhancer according to the invention makes it possible to increase the palatability of pet food. Thus, when the palatability enhancer according to the invention is present on or in an animal food, a significant increase in the consumption of said food is observed, compared with the same food in the absence of palatability enhancer according to the invention.

[0141] In a particular embodiment, the food is intended for animals, such as domestic animals, for example cats and / or dogs. The food according to the invention may be in any form suitable for animal feeding, for example in dry, semi-dry or wet form.

[0142] In a particular embodiment, the palatability enhancer according to the invention is incorporated into the food in an amount such that the palatability enhancer is present from 0.1 wt% to 20 wt% in the food, for example from 0.1 wt% to 15 wt%, from 0.1 wt% to 10 wt%, from 0.1 wt% to 5 wt%, such as from 0.5 wt% to 20 wt%, from 0.5 wt% to 15 wt%, 0.5 wt% to 10 wt%, 0.5 wt% to 5 wt%, for example 1 wt% to 20 wt%, 1 wt% to 15 wt%, 1 wt% to 10 wt% or 1 wt% to 5 wt% in the feed.

[0143] In a particular embodiment, the palatability enhancer according to the invention is applied to a food in an amount such that the palatability enhancer is present from 0.1 wt% to 20 wt% in the food, for example from 0.1 wt% to 15 wt%, from 0.1 wt% to 10 wt%, from 0.1 wt% to 5 wt%, such as from 0.5 wt% to 20 wt%, from 0.5 wt% to 15 wt%, from 0.5 wt% to 10 wt%, from 0.5 wt% to 5 wt%, for example from 1 wt% to 20 wt%, from 1 wt% to 15 wt%, from 1 wt% to 10 wt% or from 1 wt% to 5 wt% in the food.

[0144] A food, in particular a pet food, is preferably nutritionally balanced and comprises, for example, proteins, fibers, carbohydrates and / or lipids. Such foods are well known to those skilled in the art, and their composition depends on numerous factors such as, for example, the desired nutritional balance for the type of animal for which the food is intended.

[0145] In addition to these basic elements, a food, especially a pet food, may include vitamins, minerals, and other additives such as seasonings, preservatives, emulsifiers, and wetting agents.

[0146] The dietary balance, including the relative proportions of vitamins, minerals, lipids, proteins and carbohydrates, is determined according to known dietary standards for the animal for which the food is intended.

[0147] A food may include protein sources of any kind, including plant proteins such as soy or peanut, animal proteins such as casein, albumin, and fresh animal tissues, for example fresh meat tissue and fresh fish tissue, or even dry elements such as fish meal, insect meal, poultry meal, meat meal, bone meal. A food may also include wheat gluten, corn gluten meal, and microbial proteins such as yeast. A food may also include other ingredients such as whey and other milk by-products.

[0148] Vitamins and minerals that may be contained in a food include calcium carbonate, potassium chloride, sodium chloride, choline chloride, taurine, zinc oxide, ferrous sulfate, vitamin E, vitamin A, vitamin B12, vitamin D3, riboflavin, niacin, calcium pantothenate, biotin, thiamine mononitrate, copper sulfate, folic acid, pyroxidine hydrochloride, calcium iodate, and menadione sodium bisulfite complex (a source of vitamin K activity).

[0149] The palatability enhancer may be applied to the food, especially pet food, for example, by spraying, topping, coating or dusting.

[0150] The palatability enhancer may be incorporated into the food composition, in particular into a food composition for domestic animals, for example in the composition used to produce a food for domestic animals, such as a composition used to produce kibble. It may be, for example, the composition obtained before manufacture of the food, for example kibble, by extrusion. Brief description of the drawings

[0151] [Fig-1] diagram representing the different stages of a method according to the invention implementing enzymatic hydrolysis.

[0152] [Fig.2] diagram representing the different stages of a process according to the invention implementing hydrolysis by saponification.

[0153] [Fig.3] diagram representing the different stages of a process according to the invention implementing hydrolysis by saponification and enzymatic hydrolysis. Examples

[0154] Example 1: Process for preparing a palatability enhancer

[0155] 1. Method 1: Oil hydrolyzed by lipolysis then induction of a reaction of Maillard ([Fig. 1])

[0156] 1.1. Preparation of a brine

[0157] An aqueous brine was prepared by mixing NaCl and CaCl2 with gentle stirring until the salts were completely dissolved in water. The composition of the brine is shown in Table 1

[0158] [Tables 1] Ingredients Amounts (% by weight relative to the total weight of the brine) Water 96.7% NaG 0.2% caCS? 0.1%

[0159] 1.2, Preparation of an emulsion of an aqueous brine with insect oil

[0160] This step consisted of melting oil obtained from Hermetia illucens larvae at a temperature of 50°C because it solidifies at room temperature. Then, the melted oil was added to the brine and the mixture was emulsified. The amount of oil added depends on the amount of water provided by the brine. The oil:water mass ratio in the emulsion was 3:2. After adding the oil to the brine, the emulsion was formed in a few minutes (e.g. 3-5 minutes) with vigorous stirring and could then be maintained by gentler continuous stirring.

[0161] 1.3. Hydrolysis of oil by lipase

[0162] In order to optimize the efficiency of the enzymes, it is crucial to maintain the appropriate environmental conditions depending on the lipase used, such as pH, temperature, etc. The emulsion was heated to 50°C and the pH was adjusted to pH 7.5 by adding a dilute NaOH solution at 5 wt% relative to the total weight of the diluted solution. When the mixture reached a temperature of 50°C and a pH of 7.5, the enzymes (lipases) were added to the mixture at a concentration of 2 wt% triacylglycerol lipase relative to the initial amount of oil. During the lipolysis process, the release of fatty acids led to a decrease in pH. In order to maintain an optimal pH during this process, an addition of 5% NaOH sodium hydroxide at regular intervals was necessary to maintain the pH at 7.5. The lipolysis reaction lasted between 1.5 and 2 h. The hydrolysis yield reached 35-40%.

[0163] 1.4. Induction of a Maillard reaction

[0164] At the end of the oil hydrolysis process, the moisture was measured and adjusted with water to reach a target moisture of 65% to 68%. After adjusting the moisture, sugars (lactose and xylose) and then amino acids (cysteine ​​and methionine) were added to the hydrolyzed oil fraction. After adding the ingredients, the pH was then measured and adjusted using a NaOH solution to bring it back to pH 7 before starting the Maillard reaction. After adding the reagents and adjusting the pH, the temperature was raised to a temperature above 90°C to induce the Maillard reaction. A temperature hold was maintained at 90-95°C under continuous stirring for 2 hours.

[0165] 1.5. Addition of additives

[0166] After two hours, the Maillard reaction was complete. The mixture was lowered to a temperature of 50°C to allow the addition of additives. 0.3 wt% of potassium sorbate (relative to the total weight of finished product) was added to prevent mold growth and 0.3 wt% of antioxidant based on tocopherols and rosemary (relative to the total weight of finished product) to prevent oxidation of the product. Finally, to obtain a stable texture (more viscous, less risk of phase separation), a 3% xanthan gum solution was added at a rate of 7.7 wt% relative to the total weight of finished product. The pH was then adjusted to pH 3 with phosphoric acid.

[0167] 2. Method 2: Oil hydrolyzed by saponification then induction of a Maillard reaction ([Fig.2])

[0168] 2.L Hydrolysis of insect oil by saponification

[0169] Melted Hermetia illucens larvae oil at 70°C was added to a 6% NaOH solution. For complete saponification and release of fatty acids, the amount of NaOH was determined by the saponification index. 2 wt% lecithin (based on the total weight of oil and water) was then added in the mixture to maintain the emulsion during saponification. Following the addition of lecithin, the emulsion was assembled under vigorous stirring for a few minutes and then maintained by continuous moderate stirring until the end of the reaction. Saponification lasted approximately 2-3 hours with a hydrolysis yield that reached up to 90%.

[0170] 2.2, Induction of a Maillard reaction

[0171] The hydrolyzed oil then underwent the same treatment as described in point 1.4 above.

[0172] 2.3. Addition of additives

[0173] Preservatives were then added to the Maillard product to preserve the product according to the protocol described in point 1.5 above.

[0174] 3: Method 3: Oil hydrolyzed by lipolysis and saponification then induction of a Maillard reaction ([Fig.3])

[0175] 3.1. Hydrolysis of insect oil by lipolysis then by saponification

[0176] Hermetia illucens larval oil was treated following all the steps of the lipolysis process with a lipase as described in point 1 above.

[0177] After two hours of lipolysis, a conversion rate (yield) of 35 to 40% was obtained. The quantities of sodium hydroxide and water in the lipolyzed product were recalculated at the end of lipolysis. From these data, it was possible to determine the additional weights of caustic soda and water required to obtain the same concentration levels of sodium hydroxide and water as in the saponification formula. A solution of water and sodium hydroxide was prepared with these additional weights and then added to the lipolyzed product. The mixture was then heated to 70°C to start saponification. Saponification was maintained at 70°C for 1 hour.

[0178] 3.2, Induction of a Maillard reaction

[0179] After undergoing lipolysis and then saponification, the hydrolyzed oil was then treated as described in step 1.4.

[0180] 3.3. Addition of additives

[0181] Preservatives were then added to the Maillard product to preserve the product, as described in point 1.5.

[0182] Example 2: taste tests

[0183] 1. Determination of the palatability of the three products from the three methods described in Example 1

[0184] LL Preparation of three palatability enhancers

[0185] The palatability enhancers are prepared as specified below: Product A: Method 2 of Example 1. Product B: Method 1 of Example 1. Product C: Method 3 of Example 1.

[0186] 1.2 Preparation of dog kibble

[0187] Dog kibble was coated with a palatability enhancer at a rate of 2 wt% of palatability enhancer relative to the weight of kibble.

[0188] 1.3. Determination of palatability with a test consisting of the presentation of a single bowl (consumption test)

[0189] 1.3.1. Principle of the consumption test

[0190] The consumption test is based on criteria specifically selected as indicators of the animals' level of pleasure, perceptible and significant from a human point of view, such as the proportion of the ration consumed, the comparison of consumption with the individual reference consumption, the % of bowls finished, the % of refusals, the speed of consumption. The kibbles containing the three palatability enhancers were each tested on a panel of 37 adult dogs, male and female, of various breeds. The consumption test consists of presenting one bowl at a time to each dog, in individual boxes with a tray system. The test was carried out on two meals per type of kibble, with randomization according to a predefined presentation plan (sequential monadic), in order to avoid possible bias linked to the order of presentation.

[0191] 1.3.2. Preparation and execution of tests

[0192] The ration offered in the bowl was weighed. The quantity was calculated according to the individual characteristics of each animal. The test consisted of short individual meals (20 min), starting at 8:00 for the first meal and at 15:45 for the second meal. At the end of the test, the bowl was removed and weighed.

[0193] 1.3.3. Data processing

[0194] The test results are statistically analyzed in order to draw conclusions.

[0195] Several processing methods are used, depending on the parameters (Table 2).

[0196] [Tables2] Method Parameters Student test consumption of a product compared to a reference consumption. Analysis of variance consumption speed % of ration consumed Logistic regression % of bowls finished % of bowls refused

[0197] The different methods allow us to calculate the p-value (p-value ) specific. This p-value makes it possible to evaluate, for each parameter, whether the result obtained for each product tested is statistically significant (i) compared to the others or (ii) compared to the reference consumption of dogs (Table 3).

[0198] [Tables3] p-value Risk of erroneous conclusion Significance threshold > 0.05 - NS Not significant ]0.01,0.05] 11%, 5%] * Significant 10.001,0.01] ]0.1% , 1%] Highly significant <0.001 Less than 0.1% Very highly significant

[0199] 1.3.4. Appetite test results

[0200] 1.3.4.1. Analysis of the percentages of ration consumed

[0201] The percentage of the ration consumed (or consumption rate) corresponds to the quantity consumed divided by the total quantity distributed (Table 4).

[0202] [Tables4] Product A Product B Product C Consumption rate 91% 93% 91%

[0203] 1.3.4.2. Distribution of consumption

[0204] Table 5 provides additional information to Table 4, detailing the consumption levels of each product, compared to the proposed ration. It illustrates the percentage of individual meals without consumption (0%), with less than half of the ration consumed (<50%), with more than half of the ration consumed (>=50%), and almost all of the ration consumed (>=95%).

[0205] [Tables5] Product A Product B Product C % of individual meal (0-0¾] 6% 0% 4% % of individual meal [0-50%[ 1% 7% 1% % of individual meal [0-95%[ 9% 7% 14% % of individual meal [95-100%] 84% 86% 79%

[0206] 1.3.4.3. Comparison with reference consumption

[0207] This graph enriches the previous results with additional consumption criteria. The percentage of consumption compared to the reference consumption measures the quantities consumed compared to the pet's habits (the reference consumption is an average of individual consumptions calculated over the previous months). Table 6 shows the proportion of individual meals with a consumption above the reference consumption, as well as those with a consumption below the reference consumption and the average quantity consumed of each product, as a percentage of the quantity usually consumed (reference consumption).

[0208] [Tableauxô] Product A Product B Product C % of individual meals Consumption > Reference consumption 88% 90% 86% % of individual meals Consumption < Reference consumption 12% 10% 14% Average quantity consumed as % of reference consumption 114% 115% 112% Significant deviation from reference consumption w* -Ÿ *

[0209] 1.3.4.4. Percentage of finished bowls

[0210] Finished bowls are perceived as a positive signal by pet owners. A bowl is considered finished if more than 97.5% of the initial ration has been consumed (Table 7).

[0211] [Tables7] Product A Product B Product C % of finished bowls 84% ​​86% 80%

[0212] 1.3.4.5. Percentage of bowls refused

[0213] Refused bowls are perceived as a negative signal by pet owners. A bowl is considered refused if the quantity consumed is equal to 0 g (Table 8).

[0214] [Tables8] Product A Product B Product C % of bowls refused 6% 0% 4%

[0215] 1.3.4.6. Percentage of consumption speed

[0216] Consumption speed is an additional criterion for measuring product attractiveness. It is expressed as the average percentage of ration consumed per minute (Table 9).

[0217] [Tables9] Product A Product B Product C Average % of ration consumed per minute 31% 31% "î 4 Û V

[0218] 1.3.5 Conclusion

[0219] Based on the previous results, it can be seen that the dogs liked all three products. However, it should be noted that the kibbles coated with product B (lipolysis alone) were slightly more liked by the dogs than those coated with products A (hydrolysis by saponification) or C (hydrolysis by lipolysis then saponification).

[0220] 2. Determination of the effect of oil hydrolysis on palatability

[0221] 2.1, Preparation of two palatability improvers

[0222] The objective of this evaluation was to analyze the influence of hydrolysis on the palatability improver by comparing two palatability improvers, namely product D (prepared with a hydrolysis step) and product E (prepared without a hydrolysis step).

[0223] Product D was prepared according to method 1 of Example 1. However, in the step aimed at inducing a Maillard reaction, cysteine ​​and methionine were replaced by a mixture of amino acids composed in particular of leucine and glutamic acid.

[0224] Product E was prepared according to method 1, but without hydrolysis of the insect oil by lipase (lipase was not added to the mixture). However, as for product D, in the step of inducing a Maillard reaction, cysteine ​​and methionine were replaced by the mixture of amino acids composed in particular of leucine and glutamic acid mentioned in the paragraph above (product D).

[0225] 2.2, Preparation of dog kibble

[0226] The dog kibble is prepared as described in Example 2, paragraph 1.2.

[0227] 2.3. Determination of palatability with a two-bowl versus test (versus test)

[0228] 2.3.1. Principle of the test versus

[0229] The objective of this study was to measure the palatability level of two batches of dog food, one batch having been coated with product D, the other with product E, while identifying significant differences between the two diets through consumption criteria. A palatability assessment was conducted on a group of 35 adult dogs, including both males and females of different breeds. The versus methodology was implemented. It involves the simultaneous presentation of one bowl from each batch to each dog, in individual boxes equipped with a tray system. The test was carried out over two meals, with a deliberate exchange of the position of the bowls, in order to avoid any potential bias.

[0230] The criteria evaluated included: • First choice: the first type of kibble consumed by the animal. • Quantities and percentages of consumption for each batch. • Consumption rate of a batch compared to total consumption (sum of consumption of the two batches). [0231 ] 2.3.2. Preparation and execution of tests

[0232] The bowls were prepared one hour before the start of the test. The same amount of food was distributed in each bowl, after weighing. The amount was calculated based on the individual characteristics of each animal.

[0233] The test consists of short individual meals (20 min), starting at 8:00 a.m. for the first meal and at 3:45 p.m. for the second meal.

[0234] The test was considered to be finished as soon as one of the following cases occurred: • When a bowl is finished (if the dog only consumes one type of kibble). • When the equivalent of a bowl is finished (if the dog consumes both types of kibble). • After a period of 20 minutes (if no bowl is finished, or if there is not the equivalent of a finished bowl).

[0235] At the end of the test, the bowls were removed and weighed.

[0236] 2.3.3. Data processing

[0237] The test results were statistically analyzed in order to draw conclusions.

[0238] Several treatment methods were used, depending on the parameters (Table 10).

[0239] [TableauxlO] Method Parameters Student's test - consumption rate of a batch compared to h total consumption Chi-square test first choice

[0240] The different methods allow us to calculate the specific p-value. This p-value allows us to evaluate, for each parameter, whether the difference between the two products tested is statistically significant or not (Table 11). [0241 ] [T ables 11 ] p-Value Risk of erroneous conclusion Significance threshold > 0.05 - NS Not Significant ]0.01,0.05] ]1% , 5%] ¥ Significant M001 , 0.01] M1%, 1%] Highly significant <0.001 Less than 0.1% Very highly significant

[0242] 2.3.4. Appetite test results

[0243] 2.3.4.1. First choice analysis

[0244] In order to know if the animals were attracted more significantly by a product, a Chi2 test was carried out between the numbers of individuals having chosen product D as first choice and those having chosen product E (Table 12).

[0245] [Tableauxl2] Product D Product E Significance threshold % of individuals for the first meal 68% 32% NS % of individuals for the second meal 79% 21% Ÿ s- ■

[0246] Meal 1: There is no significant difference between the two batches.

[0247] Meal 2: There is a high significant difference between the two batches. The kibbles coated with product D were clearly preferred.

[0248] 2.3.4.2. Analysis of the consumption rate

[0249] The consumption rate is defined as the quantity consumed of one of the batches containing the studied products (D or E) divided by the total quantity consumed (D + E). To determine the existence of a significant difference between the consumption rates of the two products, a Student test was carried out (Table 13).

[0250] [Tables 13] Product D Product E Significance threshold % consumption for the first meal 70% 30% V % consumption for the second meal 68% 32% ÿ

[0251] Meal 1: There is a significant difference between the two batches. The kibbles containing product D were preferred.

[0252] Meal 2: There is a significant difference between the two batches. The kibbles containing product D were preferred.

[0253] 2.3.5. Conclusion

[0254] Based on the data obtained, a statistically significant distinction between the two batches (kibbles containing products D and E) was established, with the exception of the first choice observed during the first meal. Thus, it is concluded that the degree of attractiveness of the dog kibbles coated with product D is statistically higher than that of the dog kibbles coated with product E.

[0255] These results show that the oil hydrolysis step significantly increased the palatability of the kibble.

[0256] Example 3: Analysis of the composition of the palatability enhancer

[0257] The nutritional composition of product D, described in example 2, is indicated in table 14 below and compared to those of other palatability improvers available on the market.

[0258] [Tablesl4] Supplier Product Name Moisture (wt% of total product weight) Protein (wt% of total product weight) Lipid (wt% of total product weight) Ash (wt% of total product weight) pH nextProtein Product D 60 3 26 3.00 ND Improver 1 < 75 > 5 > 9 < 6 2.7-3.1 ND Improver 2 < 75 > 6 < 25 < 5 2.6-3.0 ND Improver 3 < 79 > 7 > 5 < 3 2.7-3.1 ND Improver 4 < 86 > 7 < 9 < 6 2.6-3.2 ND: undisclosed

[0259] The composition of product D highlights that this palatability enhancer is richer in lipids than in proteins (with a protein-to-dipid mass ratio of approximately 1:9). It is the product richest in lipids but also the least rich in proteins in the range of palatability enhancers compared.

[0260] A further analysis conducted according to the VDLUFA III, 5.2.1: 1976 method demonstrated that 76.2% of the lipids in product D are in the form of free fatty acids (result expressed in oleic acid equivalent). A determination of the acid number during the production of product D (according to the NF EN ISO 660 method) made it possible to quantify that 35 to 40% of the lipids were hydrolyzed during enzymatic lipolysis and the additional 36 to 41% during the Maillard reaction.

[0261] Initially, the insect oil used to prepare product D contained less than 2 wt% of free fatty acids relative to the total amount of lipids (measurement carried out according to standard NF EN ISO 660). The process developed by the Applicant was optimized in order to release a maximum of free fatty acids. These free fatty acids combined with a low protein level during the Maillard reaction make it possible to develop a palatability enhancer that is not only effective and appreciated by dogs (as shown by the studies presented in Example 2) but also has lower manufacturing costs than palatability enhancers produced from whole insects.

Claims

Claims

1. A method of preparing a palatability enhancer from insects, comprising the following steps: a. obtaining an oily fraction from insects, b. subjecting the oily fraction to hydrolysis to obtain a hydrolyzed oily fraction, c. heating the hydrolyzed oily fraction to induce a Maillard reaction.

2. Preparation process according to claim 1, in which the insects are chosen from 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, Gryllodes sigillatus, Gryllus assimillis and Samia ricini, Bombyx mori, or their mixtures, preferably Hermetia illucens.

3. Preparation process according to any one of the preceding claims, wherein the oily fraction of step a) is obtained by carrying out a process comprising the following steps: a1) grinding insects to obtain a ground material, a2) optionally, subjecting the ground material to enzymatic hydrolysis with a protease to obtain a hydrolyzed ground material, a3) optionally, pressing the ground material or the hydrolyzed ground material to obtain a solid fraction enriched in chitin and a liquid fraction, and a4) subjecting the ground material, the hydrolyzed ground material or the liquid fraction to physical separation to extract an oily fraction.

4. A preparation process according to any one of claims 1 or 2, wherein the oily fraction of step a) is obtained by carrying out a process comprising the following steps: a1') obtaining dehydrated insects, and a2') pressing the dehydrated insects in order to extract an oily fraction.

5. A preparation process according to any one of the preceding claims, wherein step b) consists of subjecting the oily fraction to (i) enzymatic hydrolysis, preferably with one or several lipase(s), and / or (ii) saponification in order to obtain a hydrolyzed oily fraction.

6. Preparation process according to any one of the preceding claims, in which the following are added to the hydrolyzed oily fraction: - one or more sugars, and - one or more compounds chosen from (i) one or more amino acids, and (ii) proteins.

7. Preparation process according to claim 6, in which the following are added to the hydrolyzed oily fraction: - one or more sugars in an amount ranging from 0.01 wt% to 80 wt% relative to the total weight of the oily fraction, and - one or more compounds chosen from (i) one or more amino acids in an amount ranging from 0.01 wt% to 80 wt% relative to the total weight of the oily fraction and (ii) proteins in an amount ranging from 0.01 wt% to 80 wt% relative to the total weight of the oily fraction.

8. Preparation process according to any one of the preceding claims, in which step c) consists of: - heating the hydrolyzed oily fraction to a temperature between 60°C and 180°C, preferably for a period of time ranging from 5 minutes to 360 minutes, or - heating the hydrolyzed oily fraction for a period of time ranging from 5 minutes to 360 minutes, preferably at a temperature between 60°C and 180°C.

9. A preparation process according to any preceding claim, wherein water is added to the oil fraction, and water is optionally added to the hydrolyzed oil fraction.

10. Preparation process according to any one of the preceding claims, in which one or more compounds chosen from a preservative, an antioxidant and a texturizing agent are added to the product obtained in step c).

11. Appetite enhancer obtainable by implementing the method according to any one of claims 1 to 10.

12. A palatability enhancer according to claim 11, comprising: - at least 20 wt% of lipids relative to the total weight of the palatability enhancer,

13.

14.

15. - less than 10 wt% of protein relative to the total weight of the palatability enhancer, - a protein-to-fat mass ratio ranging from 1:2 to 1:15, and - more than 35 wt% of fatty acids in free form relative to the total weight of lipids. Food comprising (i) at least one food ingredient, and (ii) a palatability enhancer according to claim 11 or 12. A method for improving the palatability of a food composition comprising incorporating a palatability improver according to claim 11 or 12 into a food composition. A method for improving the palatability of a food comprising applying a palatability improver according to claim 11 or 12 to a food.

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