Insect pulp and method for producing same

Abstract

The present invention relates to a method for preparing an insect pulp, to the insect pulp thus obtained and to the uses thereof in animal feed and in particular feed for domestic animals.

Description

[0001] Title: Insect pulp and its manufacturing process

[0002] TECHNICAL FIELD OF THE INVENTION

[0003]

[0001] The present invention relates to a process for preparing insect pulp, to the insect pulp thus obtained and to its uses in animal feed, and particularly in the feeding of domestic animals.

[0004] DISCLOSURE OF THE INVENTION

[0005]

[0002] With the increasing environmental concerns, the search for alternatives to usual animal proteins is becoming increasingly important not only in human food but also in animal feed.

[0006]

[0003] By usual animal proteins, it is meant proteins from animals from cattle, sheep or pig farming, fish or poultry.

[0007]

[0004] According to the FAO (Food and Agriculture Organisation), insects are considered a sustainable alternative to conventional animal proteins in the face of natural resource depletion and the growth of the world population.

[0008]

[0005] Indeed, insect farming results in a low greenhouse gas production compared to cattle or pig farming, with a high protein conversion rate.

[0009]

[0006] However, the production and transformation of insects into a food product of interest remains difficult and costly. In addition, nutritional quality and health safety are important criteria to consider in the development of an industrial-scale food product manufacturing process.

[0010]

[0007] In this context, the inventors have identified a continuous process for preparing insect pulp, the continuous process enabling efficient industrialization of the transformation of insects into a pulp that has a low microbial load and whose nutritional quality is preserved, particularly in terms of protein profile. By efficient industrialization, it is meant an industrialization at low cost and high yield.

[0008] Thus, the present invention aims at a process for preparing insect pulp from insects, comprising the following steps:

[0011] - grinding the insects,

[0012] - cooling to a temperature of 4°C or lower, said cooling step comprising a sub-step of dilution-cooling by adding water at a temperature between 4°C and 15°C, in which the grinding and cooling steps are carried out continuously.

[0013]

[0009] As used herein, "pulp" refers to a product comprising solid particles in a liquid.

[0014]

[0010] A pulp according to the invention does not comprise a buffer solution, an enzyme, or a texturing agent (e.g., a gelling agent, starch, etc.). More particularly, a pulp of insects according to the invention consists of insects and water.

[0015]

[0011] By "insects" is meant insects at any stage of development, such as an adult stage, a larval stage or a nymph stage. Preferably, the insects are at the larval stage.

[0016]

[0012] More particularly, the insects can be selected from the group consisting of Coleoptera, Diptera, Lepidoptera, Isoptera, Orthoptera, Hymenoptera, Blattoptera, Hemiptera, Heteroptera, Ephemeroptera and Mecoptera, preferably from Coleoptera, Diptera, Orthoptera and Lepidoptera.

[0017]

[0013] 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.

[0018]

[0014] More preferably, the insects are beetles. The preferably used beetles 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.

[0019]

[0015] More preferably, these are the following beetles: Tenebrio molitor, Alphitobius diaperinus, Zophobas morio, Tenebrio obscurus, Tribolium castaneum and Rhynchophorus ferrugineus, or mixtures thereof, even more preferably Tenebrio molitor and Alphitobius diaperinus.

[0020]

[0016] The insects are preferably bred and not taken from the wild. For example, the insects are bred on an insect farm. Breeding insects on a specific farm not only controls and eliminates risks associated with insect-borne diseases, but also limits risks associated with the toxicity of insect-derived food products due, for example, to the presence of insecticides. In addition, breeding allows the quality of the insect supply to be controlled and supply costs to be limited.

[0021]

[0017] When applied to a process, "continuous" means a process carried out without interruption in which a continuous flow of material is supplied, as opposed to a discontinuous or batch process.

[0022]

[0018] Insects are ground using a grinder. Advantageously, the grinder is a wet grinder of the colloidal type. Colloid grinders are generally used to reduce the size of the elements, particles, which are introduced into them. Colloid grinders consist of two main parts: a fixed part, and a rotating part (opposite the fixed part). These parts can be smooth or have textured surfaces. The product to be ground is brought into a space located between these two parts, where the grinding is carried out.

[0023]

[0019] The grinding step was successfully carried out with a colloidal type mill having the characteristics indicated below.

[0024]

[0020] Advantageously, in the method according to the invention, the grinding is carried out by a wet-phase grinder of the colloidal type, comprising a rotor of generally conical shape comprising projecting teeth and a stator.

[0025]

[0021] Indeed, the grinder comprises a rotating part called a rotor. The rotor has a general shape which is conical, and more precisely a general outer casing in the shape of a truncated cone. The rotor of the grinder comprises in particular four volutes included in this truncated conical casing, which define the surface of the rotor. The grinder is configured to drive the rotor in rotation around a central axis. The outer surface of the rotor comprises projecting teeth. These teeth form sharp helical edges, which describe a portion of a turn on the surface of the truncated cone formed by the rotor.

[0022] The grinder further comprises a fixed part called a stator. The stator has a general shape of a funnel or hopper, and forms a receiving volume for the rotor. Thus, the receiving volume formed by the rotor corresponds to the general shape of the rotor. A space remains between the stator and the rotor, where the insects are ground.The stator has teeth, which form sharp edges that extend from the base to the top of the stator.

[0026]

[0023] In the context of the present method, a textured surface of the rotor and / or the stator, suitable for causing cutting, offers better results for obtaining the desired pulp, due to the fact that the cuticle of insects, and in particular of larvae, has a certain elasticity making the latter difficult to grind.

[0027]

[0024] The crusher is fed by a device allowing the insects to be fed at a regular, continuous rate, such as pneumatic transport followed by a dosing cyclone or a volumetric or centrifugal pump.

[0028]

[0025] By dosing cyclone, we mean a device which comprises a decanter cyclone, in this case allowing the air to be evacuated, and a dosing means such as an endless screw, located in the bottom of the device, allowing the dosing and feeding of the grinder. Such a device is advantageous when the insects are brought in by a pneumatic transfer system.

[0029]

[0026] Advantageously, the volumetric or centrifugal pump will have an impeller chosen so as not to damage the insects during feeding, for example, a very open impeller.

[0030]

[0027] Advantageously, the insects may be introduced along an axial feed channel which continues into the space between the rotor and the stator. In this space, the insects are reduced to pulp by the action of the edges which act like knives to score and reduce the insects by cutting, and by the combined action of the rotor and the stator which create shear forces in the product.

[0031]

[0028] Grinders having a similar operation can of course be used in the process. Thus, the grinding step can be carried out without causing heating of the insects which could alter the properties of the pulp thus obtained.

[0032]

[0029] Advantageously, the grinding is carried out in a single step. The residence time in the grinder is preferably less than 30s, more preferably between 15 and 25s, even more preferably of the order of 10 to 20s.

[0033]

[0030] The cooling step includes a dilution-cooling sub-step by adding water to a temperature between 0°C and 15°C. The addition of water makes it possible both to cool the pulp and also to dilute it and therefore to reduce the dry matter content. At the end of the dilution-cooling sub-step, the insect pulp advantageously has a dry matter content of between 20 and 30% by weight, preferably between 23 and 27% by weight, even more preferably between 24 and 26% by weight, the percentage by weight being expressed relative to the total weight of the pulp.

[0034]

[0031] It will be noted that in the context of the present application, and unless otherwise stipulated, the ranges of values ​​indicated are understood to be inclusive. It will be noted that in the context of the present application, the terms "weight percentage" and "mass percentages" are equivalent.

[0035]

[0032] However, the addition of water is insufficient to obtain a pulp at a temperature below 4°C.

[0036]

[0033] Therefore, in the method according to the invention, the cooling step also comprises a sub-step of cooling by heat transfer.

[0037]

[0034] “Heat transfer cooling” means cooling in which the thermal energy of one fluid is transferred to another fluid without mixing them.

[0038]

[0035] During the cooling step, the two sub-steps can be carried out one before the other or simultaneously.

[0039]

[0036] Advantageously, the device allowing cooling by heat transfer is chosen from a continuous reactor with injection of liquid nitrogen, an in-line dynamic mixer with injection of liquid nitrogen, heat exchangers or a combination of these.

[0040]

[0037] By continuous reactor with liquid nitrogen injection, we mean industrial equipment comprising a tank whose bottom is equipped with liquid nitrogen injection nozzles, said tank comprising a stirring device.

[0041]

[0038] By in-line dynamic mixer with liquid nitrogen injection is meant industrial equipment used to continuously mix substances while incorporating liquid nitrogen into the process. It can be used to continuously cool a substance such as a sauce or any other fluid or pasty substance, and can therefore be referred to as a cooler, or according to the English expression "sauce chiller".

[0042]

[0039] Such a dynamic mixer has moving elements, such as blades, which create a mixing movement, a turbulence, in the substance introduced into the mixer. The mixer is called "in-line" because it is integrated directly into the production flow, thus allowing continuous mixing of the substance as it passes through it. In practice, the dynamic mixer comprises a cylindrical mixing chamber into which the product to be cooled flows, while a shaft carrying blades, which extends along the main axis of the cylindrical mixing chamber, is driven in rotation, for example using a motor.

[0043]

[0040] Cooling is achieved by injecting liquid nitrogen, for example introduced radially into the mixing chamber. Nitrogen is an inert gas that can be cooled to very low temperatures to become liquid.

[0044]

[0041] By heat exchangers, we are referring more particularly to a wide gap plate heat exchanger and / or a tubular type heat exchanger such as a scraped surface exchanger.

[0045]

[0042] Wide-spaced plate heat exchangers and tubular heat exchangers are supplied with refrigerant liquid by devices called refrigeration units.

[0046]

[0043] According to a first embodiment of the cooling by heat transfer, the cooling by heat transfer is provided by a continuous reactor with injection of liquid nitrogen and / or an in-line dynamic mixer with injection of liquid nitrogen.

[0047]

[0044] Advantageously, when a continuous reactor with liquid nitrogen injection is used, the dilution-cooling sub-step is carried out simultaneously with the heat transfer cooling sub-step since the water is introduced into the reactor simultaneously with the insect pulp.

[0048]

[0045] When an in-line dynamic mixer with liquid nitrogen injection is used, the dilution-cooling sub-step is carried out before the heat transfer cooling sub-step since the water is added to the insect pulp before introducing it into the mixer.

[0049]

[0046] According to a second embodiment of the cooling by heat transfer, the cooling by heat transfer is provided by one or more heat exchangers.

[0050]

[0047] In this embodiment, the water from the dilution-cooling sub-step is added prior to the introduction of the pulp into the heat exchanger(s). In this embodiment, the dilution sub-step is therefore carried out before the heat transfer cooling sub-step.

[0051]

[0048] Advantageously, the heat transfer cooling is carried out by one or more wide-spaced plate heat exchangers and one or more scraped surface exchangers, in that order.

[0052]

[0049] In this second embodiment of the cooling by heat transfer, it is possible, if necessary, to supplement the cooling by heat transfer by passing the insect pulp through a continuous reactor with injection of liquid nitrogen and / or an in-line dynamic mixer with injection of liquid nitrogen.

[0053]

[0050] At the end of the cooling step, the temperature of the pulp is at a temperature less than or equal to 4°C, preferably between 1 and 4°C.

[0054]

[0051] According to a first particular embodiment of the method according to the invention, the method for preparing an insect pulp from insects comprises the following steps: a) blanching the insects, b) grinding the insects, c) heating to a temperature of at least 80°C, d) cooling to a temperature less than or equal to 4°C, said cooling step comprising a dilution-cooling sub-step by adding water to a temperature between 4°C and 15°C, in which steps a) to d) are carried out continuously.

[0055]

[0052] The blanching step makes it possible to wash the insects (removing pieces of frass, molts and substrates stuck to the insects), to lower the microbial load (reducing the risk of spoilage and sanitation) and to inactivate the internal enzymes thus preventing autolysis and rapid browning of the insects. The blanching step according to the invention also has the advantage of preserving the integrity of proteins contained in the insects.

[0056]

[0053] The blanching step is generally carried out by spraying the insects with water at a temperature between 80 and 98°C, preferably between 85 and 97°C, more preferably between 90 and 97°C, even more preferably between 92 and 95°C. Preferably, the insects are blanched in water at a temperature of 94 or 95°C.

[0057]

[0054] The bleaching step is carried out in a device called a bleacher.

[0058]

[0055] The term “whitening” means a device for bleaching insects.

[0059]

[0056] The residence time of the insects in the whitener is between 1 and 15 min, preferably between 3 and 10 min.

[0060]

[0057] For example, the residence time of the insects in the bleaching unit is 9 min when the temperature of the sprayed water is 94°C, or 7 min when the temperature of the sprayed water is 95°C. These residence times and temperatures allow a good logarithmic reduction of Clostridium perfringens and Bacillus cereus, which are heat-resistant bacteria.

[0061]

[0058] Advantageously, the method according to the first particular embodiment comprises a boiling step, prior to the blanching step, said boiling step being carried out continuously with steps a) to d).

[0062]

[0059] By "scalding step" we mean a step during which the insects, transported, are plunged into a bath of "boiling" water. This scalding step makes it possible in particular to cause death as quickly as possible, while respecting animal welfare, and according to scientific recommendations. It also makes it possible to carry out an initial washing of the insects.

[0063]

[0060] By “boiling” water, we are referring more particularly to water whose temperature is between 65 and 97°C, preferably between 70 and 90°C, more preferably between 70 and 85°C. Preferably, the boiling step is carried out at a temperature of 75°C.

[0064]

[0061] Advantageously, the scalding step lasts between 1 and 20 seconds, preferably between 2 and 12 seconds.

[0062] In the method according to the first particular embodiment of the invention, after blanching, the insects are then sent via a transfer and / or feed system (such as a pneumatic transfer followed by the dosing cyclone, a volumetric or centrifugal pump as described above) to the grinding step. The grinding step is as described in the general method above.

[0065]

[0063] At the end of the grinding step, the pulp obtained undergoes a heating step.

[0066]

[0064] The purpose of this heating step is to again reduce the microbial load of the insect pulp.

[0067]

[0065] In the heating step, the insect pulp is heated to a temperature of at least 80°C, preferably between 80°C and 130°C.

[0068]

[0066] According to a first embodiment of the heating step, the insect pulp is sent into a tank heated to a temperature between 80 and 100°C, preferably between 85 and 100°C, more preferably between 90 and 100°C, even more preferably between 92 and 95°C.

[0069]

[0067] In this embodiment, the residence time of the pulp in the tank during the heating step is between 30 minutes and 4 hours, preferably between 1 hour and 3 hours, even more preferably between 1 hour 30 minutes and 2 hours 30 minutes.

[0070]

[0068] According to a second embodiment of the heating step, the pulp is subjected to in-line sterilization. In-line sterilization can be carried out using a microwave-type device or by direct steam injection (“DSI”).

[0071]

[0069] A DSI type device allows instantaneous heat transfer from the steam to the pulp.

[0072]

[0070] In this type of device, the steam is injected at a temperature of 165°C (6 barg) to 192°C (12 barg), depending on the pressure used. The residence time of the insect pulp in the DSI device is of the order of 1 to 10 seconds.

[0073]

[0071] A microwave type device (or microwave tube) is a continuous industrial microwave heating system, which uses a magnetron to generate microwaves to heat the product passing through the tube.

[0072] In this type of device, the microwave power is 70 to 400 kW, depending on the flow rate implemented in the continuous process. Preferably, the microwave power is 75 to 300 kW.

[0074]

[0073] In this embodiment, the residence time of the pulp in the microwave type device is between 1 and 10 seconds, preferably 1 to 5 seconds.

[0075]

[0074] At the outlet of the microwave or DSI type devices, which allow the temperature of the pulp to be raised to a temperature of 120°C, a chamber is positioned, which corresponds to a certain length of piping, in which the pulp is maintained at this temperature (120°C). This length of piping corresponds to the residence time that is desired to respect the desired sterilization scale. It depends not only on the temperature, but also on the flow rate and the type of piping used. For example, to kill 3 log of clostridium perfringens at 120°C, a residence time of 77s is required, therefore at a flow rate of 2.1 t / h, 12m of DN65 piping will be required. At a higher temperature, such as 125°C, the residence time is 25s, or a length of 4m. Alternatively, at 125°C and a flow rate of 6.6t / h, a residence time of 25s and 5m of DN100 pipe length are required.

[0076]

[0075] Advantageously, whatever the embodiment, the heating step is carried out without adding water.

[0077]

[0076] The cooling step is also as described in the general method above.

[0078]

[0077] According to a second particular embodiment of the method according to the invention, the method for preparing an insect pulp from insects comprises the following steps: i. sterilization of the insects, ii. grinding of the insects, ill. cooling to a temperature less than or equal to 4°C, said cooling step comprising a dilution-cooling sub-step by adding water to a temperature between 4°C and 15°C, in which steps i. to ill. are carried out continuously.

[0079]

[0078] According to this second particular embodiment: - the sterilization step is an in-line sterilization step as described above in the first particular embodiment, which can be carried out using a microwave type device or by direct steam injection (“DSI”, Direct Steam Injection”);

[0080] - the grinding and cooling steps being as described in the general process above.

[0081]

[0079] Advantageously, the method according to the second particular embodiment comprises a bleaching step prior to the sterilization step.

[0082]

[0080] The objective of this blanching step is to clean the insects and to bring their temperature to a temperature of 80-95°C, such as around 90°C. It can be carried out with a blanching device according to the methods described above in the first particular embodiment.

[0083]

[0081] Advantageously, and whatever the embodiment, in the method according to the invention, at the end of the cooling step, the insect pulp is stored and / or frozen.

[0084]

[0082] Advantageously, and whatever the embodiment of the method according to the invention, the latter does not include a step of fractionating the pulp.

[0085]

[0083] Advantageously, and whatever the embodiment of the method according to the invention, the method is also carried out without adding a pH adjuster.

[0086]

[0084] The invention also relates to an insect pulp comprising:

[0087] - a dry matter content of between 20 and 30% by weight expressed in relation to the total weight of the insect pulp,

[0088] - a protein content of at least 45% by weight expressed in relation to the dry weight of the pulp,

[0089] - a lipid content of at least 20% by weight expressed in relation to the dry weight of the pulp, and

[0090] - a microorganism content of less than 1000 cfu / g.

[0091]

[0085] Preferably, the above insect pulp is obtained by the preparation process according to the invention.

[0086] Preferably, the dry matter content is obtained from the determination of the humidity level according to the method resulting from regulation EC152 / 2009.

[0092]

[0087] Advantageously, the pulp according to the invention comprises a dry matter content of between 23 and 27% by weight, the percentage by weight being expressed relative to the total weight of the pulp.

[0093]

[0088] Preferably, the pulp comprises a dry matter content of between 24 and 26% by weight, preferably 25% by weight, the percentage by weight being expressed relative to the total weight of the pulp.

[0094]

[0089] 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.

[0095]

[0090] Advantageously, the pulp comprises between 45 and 70% by weight of proteins, preferably between 49 and 65%, more preferably between 52 and 60%, the percentages by weight being expressed relative to the dry weight of the pulp.

[0096]

[0091] 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. By "proteins", unless otherwise indicated, is meant not only proteins but also peptides and free amino acids.

[0097]

[0092] Advantageously, the pulp comprises at least 20% of essential amino acids, preferably between 20% and 55%, more preferably between 30% and 45% by weight of essential amino acids, the percentages by weight being expressed relative to the total weight of proteins in the pulp.

[0098]

[0093] By "total protein weight" or "protein weight" without further indication of the nature of the proteins, we mean the weight of crude proteins present in the pulp. This therefore includes water-soluble and insoluble proteins.

[0099]

[0094] Preferably, the level of essential amino acids is determined according to ISO 13903:2005 (except for tryptophan) and EC152 / 2009 regulation (for tryptophan).

[0095] The term "essential amino acid" means the following amino acids: histidine, isoleucine leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine and arginine.

[0100]

[0096] Advantageously, the insect pulp comprises a decomposition rate into sensitive amino acids of less than 30%, preferably less than 20%, more preferably less than 10% by weight of the amino acids.

[0101]

[0097] "Sensitive amino acids" means amino acids that are susceptible to oxidation under the effect of temperature. Sensitive amino acids are arginine, glutamate, leucine, glycine, lysine, methionine, cystine and cysteine.

[0102]

[0098] Indeed, as demonstrated in Example 4 (see Table 6), the amino acid content is similar before and after the heating step, including for sensitive amino acids. Consequently, the process according to the invention makes it possible to obtain a pulp whose protein profile is preserved.

[0103]

[0099] It follows that, despite the possible heating step, the proteins in the pulp do not undergo (or only slightly) a Maillard reaction.

[0104]

[0100] Advantageously, the pulp comprises at least 60% by weight of insoluble proteins, preferably between 60 and 90%, even more preferably between 70 and 85%, the percentages by weight being expressed relative to the total weight of proteins.

[0105]

[0101] Advantageously, the pulp comprises a content greater than 60%, preferably between 70% and 90%, more preferably between 75% and 85% by weight of water-soluble proteins having a size less than 12400 g / mol, on the total weight of water-soluble proteins.

[0106]

[0102] 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 4.

[0107]

[0103] By "insoluble proteins" is meant proteins insoluble in the ACN / water / TFA solution, as detailed in Example 4.

[0108]

[0104] Advantageously, the pulp 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.

[0109]

[0105] Preferably, the size of the proteins is determined by HPLC-SEC as detailed in Example 4.

[0110]

[0106] Advantageously, the insect pulp comprises between 20% and 40% by weight of lipids, expressed on the dry weight of the pulp, preferably between 21% and 38% by weight of lipids, more preferably between 25% and 35% by weight of lipids on the dry weight of the pulp.

[0111]

[0107] 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 by following the method of EC Regulation 152 / 2009, as detailed in Example 4.

[0112]

[0108] Similarly, it is noted that despite the heating step, the lipids are also preserved (little or no oxidation).

[0113]

[0109] Advantageously, the pulp has a pepsin and / or ileal digestibility of between 85% and 95%, preferably between 88% and 94%, more preferably between 89% and 93%.

[0114]

[0110] Preferably, pepsin digestibility is measured according to Directive 72 / 199 / EEC and the ISO 6655 method.

[0115]

[0111] Ileal digestibility is measured according to the BOISEN method.

[0116]

[0112] Advantageously, the insect pulp comprises an ash content of less than 10% by weight expressed on the dry weight of the pulp. Preferably, the pulp comprises an ash content of between 0% and 8% by weight, preferably between 0 and 5% by weight on the dry weight of the pulp.

[0117]

[0113] Preferably, the ash content is determined according to a method of EC Regulation 152 / 2009 as detailed in Example 4.

[0118]

[0114] Advantageously, the insect pulp comprises a fiber content of less than 15% by weight expressed on the dry weight of the pulp. Preferably, the pulp comprises a fiber content of between 2 and 10%, preferably between 3 and 8% by weight of fiber expressed on the dry weight of the pulp.

[0119]

[0115] Preferably, the fiber content is determined from the crude cellulose content as detailed in Example 4.

[0116] The pulp according to the invention has the advantage of having a low microbial load. The bleaching and heating steps detailed above make it possible to significantly reduce the microbial load of the insect pulp.

[0120]

[0117] “Low microbial load” means a microorganism content of less than 1000 cfu / g. The term microorganisms refers to bacteria such as mesophilic aerobic flora, mesophilic lactic acid bacteria, E. Coli, presumptive Bacillus cereus, Clostridium perfringens, Enterobacteriaceae and / or Salmonella; yeasts and / or molds.

[0121]

[0118] Advantageously, the insect pulp comprises a content of less than 1000 cfu / g of mesophilic aerobic flora, as determined according to the NF EN ISO 4833-1 method.

[0122]

[0119] Advantageously, the insect pulp comprises a content of less than 1,000 cfu / g of mesophilic lactic acid bacteria, as determined according to the NF ISO 15214 method.

[0123]

[0120] Advantageously, the insect pulp comprises a content of less than 100 cfu / g of yeasts and molds, as determined according to method NF V08-059.

[0124]

[0121] Advantageously, the insect pulp comprises a content of less than 10 cfu / g of E.Coli, as determined according to the NF ISO 16649-2 method.

[0125]

[0122] Advantageously, the insect pulp comprises a content of less than 40 cfu / g of Bacillus cereus, as determined according to the BKR 23 / 06 - 02 / 10 method.

[0126]

[0123] Advantageously, the insect pulp comprises a content of less than 10 cfu / g of Clostridium perfringens, as determined according to the NF EN ISO 7937 method.

[0127]

[0124] Advantageously, the insect pulp comprises a content of less than 10 cfu / g of Enterobacteria, as determined according to the NF EN ISO 21528-2 method.

[0128]

[0125] Advantageously, the insect pulp does not contain salmonella type bacteria as determined according to the BKR 23 / 07-10 / 11 method.

[0129]

[0126] As mentioned previously, a pulp is defined as a product comprising solid particles in a liquid.

[0127] Advantageously, the insect pulp comprises particles having a particle size such that 100% of the particles have a size less than 1200 pm (d100<1200 pm), preferably 100% of the particles have a size less than 1000 pm (d100<1000 pm).

[0130]

[0128] Advantageously, and preferably in addition, the particle size of the insect pulp is such that 90% of the particles have a size less than 900 pm (d90<900 pm), preferably less than or equal to 700 pm (d90=700 pm).

[0131]

[0129] By particle size distribution, we mean the study of the statistical distribution of the sizes of the particles of the pulp. The determination of the particle size distribution can be determined by different methods known to those skilled in the art. By way of example, and preferably, we can cite laser diffraction.

[0132]

[0130] Preferably, the insects are as described previously for the method. In particular, the insects are beetles and more preferably, those described above.

[0133]

[0131] The invention finally aims at the use of the insect pulp according to the invention, for the preparation of animal feed.

[0134]

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

[0135]

[0133] Advantageously, the insect pulp according to the invention is used in the feeding of domestic animals such as dogs, cats, birds, rodents, terrestrial reptiles, and fish. Preferably, the insect pulp is used in the feeding of dogs.

[0136]

[0134] Advantageously, the food is in the form of granules, flakes, pâté, kibble or treats, preferably in the form of pâté.

[0137]

[0135] The present invention also relates to an insect pulp capable of being obtained by a process as described above.

[0138] DETAILED DESCRIPTION OF THE INVENTION

[0139]

[0136] Example 1: First process for preparing insect pulp according to the invention

[0140]

[0137] Live T. molitor larvae are introduced at a flow rate of 1.9 t / h into a blanching type machine capable of both scalding the insects and blanching the scalded insects. The scalding of the larvae is carried out in a hot water bath at 75°C for approximately 9 seconds.

[0141]

[0138] The scalded larvae then pass into the blanching area of ​​the machine, where water at 94°C is sprayed on them for about 15 minutes. These scalding and blanching steps significantly reduce the microbial load (particularly enterobacteria, yeasts and molds). During their passage through the blanching area, the larvae take on about 8 to 10% of their weight in water.

[0142]

[0139] The blanched larvae are then sent by pneumatic transfer at a flow rate of 2.1 t / h, via a transfer system to a dosing cyclone allowing their introduction into a grinder via a "rain" feed. The grinder used is a colloidal type wet-phase grinder comprising a generally conical rotor and a stator. Grinding is carried out in a single stage (i.e. in a single pass through the grinder), while making it possible to obtain an insect pulp comprising particles having a particle size such that d100<1200pm, preferably d100<1200pm, and d90<900pm, preferably d90=700pm. At the grinder outlet, the pulp is at a temperature between 90-92°C and has a dry matter content of around 31%.

[0143]

[0140] The pulp is then sent by heat-insulated transfer to a tank to undergo a heating step. The tank is maintained at 90°C via a double jacket into which steam (alternatively, oil or hot water) is introduced, and the residence time of the pulp in the tank is between 30 minutes and 4 hours. This heat treatment again makes it possible to lower the microbial load of the pulp.

[0144]

[0141] Alternatively, the heating step may be performed by in-line sterilization using a microwave-type device or by direct steam injection (“DSI”).

[0145]

[0142] In the case where sterilization is carried out with a microwave type device, the power required is 75kW for a residence time of 2.5s.

[0143] In the case where sterilization is carried out with a DSI type device, the steam pressure is between 6 (165°C) and 12 barg (192°C). For a flow rate of 2.1 t / h, the steam consumption is of the order of 50kg / h and the residence time is approximately 3s.

[0146]

[0144] At the outlet of the microwave or DSI type devices, which allow the temperature of the pulp to be raised to a temperature of 120°C, a chamber is positioned, which corresponds to a certain length of piping, in which the pulp is maintained at this temperature (120°C). This length of piping corresponds to the residence time that is desired to respect the desired sterilization scale. For example, to kill 3 log of clostridium perfringens at 120°C, a residence time of 77s is required, therefore at a flow rate of 2.1t / h, 12m of DN65 piping will be required. At a higher temperature, such as 125°C, the residence time is 25s, or a length of 4m.

[0147]

[0145] At the outlet of the tank, the pulp heated to a temperature greater than or equal to 90°C, is sent to a cooling stage. The cooling stage comprises a dilution-cooling sub-stage as well as a heat transfer cooling sub-stage. For the dilution-cooling stage, water at a temperature less than or equal to 13°C, preferably such as 4°C or even 2°C, is added at a flow rate of 0.5t / h. For heat transfer cooling, this is preferably carried out in a continuous reactor with liquid nitrogen injection and / or an in-line dynamic mixer with liquid nitrogen injection. When a continuous reactor with liquid nitrogen injection is used, the water is added simultaneously to the pulp in the reactor. When an in-line dynamic mixer with liquid nitrogen injection is used, the water is added to the pulp before entering the mixer.

[0148]

[0146] At the end of the cooling step, the pulp is at a temperature between 0 and 4°C. Optionally, an antioxidant, such as tocopherol or rosemary essential oils, may be added to the pulp, for example, in a similar manner to the dilution-cooling water.

[0149]

[0147] At the end of this cooling step, the pulp has a dry matter content of approximately 25% by weight of the total weight of the pulp.

[0148] The pulp can then be stored at a temperature between 0 and 4°C in tanks before optional freezing at a temperature of -18°C.

[0150]

[0149] Example 2: Second process for preparing insect pulp according to the invention

[0151]

[0150] Live T. molitor larvae are introduced at a flow rate of 6.1 t / h into a blanching machine capable of both scalding the insects and blanching the scalded insects. The larvae are scalded in a hot water bath at 75°C for 3 seconds.

[0152]

[0151] Then the scalded larvae pass into the blanching area of ​​the machine, in which water at 95°C is sprayed on them for 6 minutes.

[0153]

[0152] The blanched larvae are then sent, at a flow rate of 6.6t / h, to a grinder. The grinder used is a colloidal type wet-phase grinder comprising a generally conical rotor and a stator. Grinding is carried out in a single stage (i.e. in a single pass through the grinder), while making it possible to obtain an insect pulp comprising particles having a particle size such that d100<1200pm, preferably d100<1200pm, and d90<900pm, preferably d90=700pm. At the outlet of the grinder, the pulp is at a temperature between 90-92°C and has a dry matter content of around 31%.

[0154]

[0153] The pulp is then sent by heat-insulated transfer to a tank to undergo a heating step. The tank is maintained at 90°C via a double jacket into which steam (alternatively, oil or hot water) is introduced, and the residence time of the pulp in the tank is between 30 minutes and 4 hours. This heat treatment again makes it possible to lower the microbial load of the pulp.

[0155]

[0154] Alternatively, as for Example 1, the heating step can be carried out by in-line sterilization using a microwave-type device or by direct steam injection (“DSI”).

[0156]

[0155] In the case where sterilization is carried out with a microwave type device, the power required is 150kW for a residence time of 2.5s.

[0156] In the case where sterilization is carried out with a DSI type device, the steam pressure is between 6 and 12 barg. For a flow rate of 6.6t / h, the steam consumption is of the order of 150kg / h and the residence time is approximately 1 s.

[0157]

[0157] At the outlet of the microwave or DSI type devices, which allow the temperature of the pulp to be raised to a temperature of 125°C, a chamber is positioned, which corresponds to a certain length of piping, in which the pulp is maintained at this temperature (125°C). This length of piping corresponds to the residence time that is desired to respect the desired sterilization scale. For example, to kill 3 log of clostridium perfringens at 125°C, a residence time of 25s is required, therefore at a flow rate of 6.6t / h, 5m of DN100 piping will be required.

[0158]

[0158] At the outlet of this tank, the pulp heated to a temperature greater than or equal to 90°C, is sent to a cooling stage. The cooling stage comprises a dilution-cooling sub-stage as well as a heat transfer cooling sub-stage. In this embodiment, the dilution-cooling sub-stage is carried out by adding water to the insect pulp by means of a static mixer. The water at a temperature less than or equal to 13°C, preferably such as 4°C or even 2°C, is added at a flow rate of 1.6 t / h. The insect pulp, at a flow rate of 8.2 t / h, is then cooled by heat transfer by means of heat exchangers. The heat exchangers are advantageously scraped surface exchangers arranged in series, possibly preceded by one or more plate heat exchangers.Optionally, a continuous reactor with liquid nitrogen injection or an in-line dynamic mixer with liquid nitrogen injection can also be added at the end of the cooling step. At the end of the cooling step, the pulp is at a temperature between 0 and 4°C. Optionally, an antioxidant, such as tocopherol or rosemary essential oils, can be added to the pulp, for example, at the outlet of the heat exchangers.

[0159]

[0159] At the end of this cooling step, the insect pulp has a dry matter content of approximately 25% by weight of the total weight of the insect pulp.

[0160] The insect pulp can then be stored at a temperature between 0 and 4°C in tanks before optional freezing at a temperature of -18°C.

[0160]

[0161] Example 3: Third method for preparing insect pulp according to the invention

[0161]

[0162] Live T. molitor larvae are introduced at a flow rate of 6.1 t / h into a blancher in order to wash them and heat them to a temperature of around 90°C.

[0162]

[0163] They are then sterilized in line using a microwave-type device or by direct steam injection (“DSI”) at a flow rate of 6.4t / h.

[0163]

[0164] In the case where sterilization is carried out with a microwave type device, the power required is 300kW for a residence time of 2.5s.

[0164]

[0165] In the case where sterilization is carried out with a DSI type device, the steam pressure is between 6 and 12 barg. For a flow rate of 6.4t / h, the steam consumption is around 300kg / h and the residence time is approximately 1.7s.

[0165]

[0166] At the outlet of the microwave or DSI type devices, which allow the temperature of the pulp to be raised to a temperature of 125°C, a chamber is positioned, which corresponds to a certain length of piping, in which the pulp is maintained at this temperature. This length of piping corresponds to the residence time that is desired to respect the desired sterilization scale. For example, to kill 3 log of clostridium perfringens at 125°C, a residence time of 25s is required, therefore at a flow rate of 6.4t / h, 5m of DN100 piping will be required.

[0166]

[0167] Then the sterilized larvae are then sent at a flow rate of 6.4t / h, via a transfer system, such as a volumetric pump, to a grinder. The grinder used is a colloidal type wet mill comprising a generally conical rotor and a stator. Grinding is carried out in a single stage (i.e. in a single pass through the grinder), while making it possible to obtain an insect pulp comprising particles with a particle size such that d100<1200pm, preferably d100<1200pm, and d90<900pm, preferably d90=700pm. At the outlet of the grinder, the pulp is at a temperature of around 99-100°C and has a dry matter content of around 31%.

[0167]

[0168] At the outlet of the grinder, the pulp is sent to a cooling stage. The cooling stage includes a dilution-cooling sub-stage as well as a heat transfer cooling sub-stage. In this embodiment, the dilution-cooling sub-stage is carried out by adding water to the insect pulp using a static mixer. The water, at a temperature less than or equal to 13°C, preferably such as 4°C or even 2°C, is added at a rate of 1.6 t / h. The insect pulp, at a rate of 8.1 t / h, is then cooled by heat transfer using heat exchangers. The heat exchangers are advantageously scraped surface exchangers arranged in series, possibly preceded by one or more plate heat exchangers.Optionally, a continuous reactor with liquid nitrogen injection or an in-line dynamic mixer with liquid nitrogen injection can also be added at the end of the cooling step. At the end of the cooling step, the pulp is at a temperature between 0 and 4°C. Optionally, an antioxidant, such as tocopherol or rosemary essential oils, can be added to the pulp, for example, at the outlet of the heat exchangers.

[0168]

[0169] At the end of this cooling stage, the insect pulp has a dry matter content of approximately 25% by weight of the total weight of the insect pulp.

[0169]

[0170] The insect pulp can then be stored at a temperature between 0 and 4°C in tanks before optional freezing at a temperature of -18°C.

[0170]

[0171] Example 4: Characterization of insect pulp according to the invention

[0171]

[0172] The pulp obtained in Example 1 was characterized as follows.

[0172]

[0173] 1. Analyses

[0173]

[0174] 1.1 Determination of dry matter content

[0174] The dry matter content was calculated from the moisture content, determined according to the method from EC Regulation 152 / 09.

[0175] 12 Determination of the quantity of protein

[0175] The protein level was determined according to the Kjeldahl method, of EC Regulation 152 / 2009, with a conversion factor N to protein of 6.25.

[0176]

[0176] 1.3 Determination of the quantity of lipids

[0177] The amount of lipids was determined according to EC Regulation 152 / 2009.

[0178]

[0177] 1.4 Determination of the quantity of ash

[0179] The ash content was determined according to EC Regulation 152 / 2009.

[0180]

[0178] 1.5 Determination of the quantity of fibers

[0181] The fiber content was determined from the crude cellulose content determined gravimetrically using a Fibersac ® device.

[0182]

[0179] 1.6 Determination of the quantity of amino acids

[0183] The amount of total amino acids was determined according to ISO 13903:2005 and EC Regulation 152 / 2009 (for tryptophan).

[0184]

[0180] 1.7 Determination of pepsin digestibility

[0185] Peptic digestibility was determined according to Directive 72 / 199 / EEC and the ISO 6655 method

[0186]

[0181] 1.8 Determination of ileal digestibility

[0187] Ileal digestibility was determined according to the BOISEN methods (for enzyme dosage) and the Dumas method (for protein content).

[0188]

[0182] 1.9 Determination of the quantity of soluble and insoluble proteins The quantity of soluble proteins was determined by solubilization of 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 of the total volume of solution, which constitutes the mobile phase before determination by HPLC-SEC (steric exclusion chromatography method known to those skilled in the art).

[0189] The amount of insoluble protein was determined by the dry residue obtained after dissolving a dried pulp sample in the ACN / water / TFA solution, and related to the initial dry weight.

[0190]

[0183] 1.10 Determination of protein size

[0191] Protein size was determined by HPLC-SEC.

[0192]

[0184] 1 .11 Determination of the quantity of minerals

[0193] The content of each of the minerals listed in Table 8 below was determined by ICP / AES (inductively coupled plasma-atomic emission spectrometry).

[0185] 1.12 Determination of the quantity of heavy metals and mycotoxins

[0194] Heavy metal content was determined by ICP-MS (Inductively Coupled Plasma Mass Spectrometry) after microwave mineralization.

[0195] Mycotoxin content was determined for zearalenone and T2 / HT-2 toxins by extraction, purification and analysis by LC MS / MS (liquid chromatography coupled with mass spectrometry), and for aflatoxins and ochratoxin by HPLC-Fluorimetry (high performance liquid chromatography coupled with a fluorescence detector).

[0196]

[0186] 2. Results

[0197]

[0187] [Table 1]

[0198] *average results calculated on 8 pulps

[0199] **average results calculated on 7 pulps

[0200] ***average results calculated on 7 pulps

[0201] ****average results calculated on 2 pulps

[0202]

[0188] Table 1: Composition of the pulp

[0203]

[0189] [Table 2]

[0204]

[0205]

[0191] Table 2: Amino acid content in the pulp

[0206]

[0192] [Table 3]

[0207]

[0193] Table 3: Protein size

[0208]

[0194] [Table 4]

[0209]

[0195] Table 4: Digestibility

[0210]

[0196] [Table 5]

[0211]

[0197] Table 5: Measurement of peptic digestibility and protein content before and after heating to 90°C

[0212]

[0198] [Table 6]

[0213]

[0214]

[0199] Table 6: Amino acid content in g per 100g at 25% dry matter, before heating (0 min) and after heating at 90°C for 30 min, 2H or 3H.

[0215]

[0200] Tables 5 and 6 show that the quality of the pulp proteins is not degraded by the heating step.

[0216]

[0201] Indeed, we note that the digestibility of proteins is similar at T=0 (i.e. without heating the pulp) and at T=60 min, taking into account the standard error. However, digestibility is a good indicator of protein quality. Indeed, the more the proteins are denatured, the less digestible they are.

[0217]

[0202] Furthermore, the amino acid profile of the pulp is not modified by the heating step, and this also applies to the most sensitive amino acids, namely lysine, methionine and cysteine.

[0218]

[0203] The process according to the invention therefore makes it possible to obtain a pulp whose amino acid profile is not altered and avoids the degradation of proteins.

[0219]

[0204] [Table 7]

[0220]

[0221]

[0205] Table 7: Minerals

[0222]

[0206] [Table 8]

[0223]

[0207] Table 8: Fatty acid contents in the pulp

[0224]

[0208] [Table 9]

[0225]

[0226]

[0209] Table 9: Heavy metal and mycotoxin content in the pulp

[0227]

[0210] [Table 10]

[0228]

[0211] Table 10: Results of microbiological analysis of the pulp

Claims

Claims 1. A method of preparing an insect pulp from insects comprising the following steps: - crushing insects, - cooling to a temperature less than or equal to 4°C, said cooling step comprising a dilution-cooling sub-step by adding water at a temperature between 4°C and 15°C, in which the grinding and cooling steps are carried out continuously.

2. Method according to claim 1, in which the grinding is carried out by a colloidal type wet mill, comprising a rotor of generally conical shape comprising projecting teeth and a stator.

3. Method according to claim 1 or 2, in which the cooling step also comprises a sub-step of cooling by heat transfer.

4. A method for preparing an insect pulp from insects according to any one of claims 1 to 3, comprising the following steps: a) blanching the insects, b) grinding the insects, c) heating to a temperature of at least 80°C, d) cooling to a temperature of less than or equal to 4°C, said cooling step comprising a dilution-cooling sub-step by adding water to a temperature between 4°C and 15°C, wherein steps a) to d) are carried out continuously.

5. Method according to claim 4, comprising a boiling step, prior to the blanching step, said boiling step being carried out continuously with steps a) to d).

6. A method of preparing an insect pulp from insects according to any one of claims 1 to 3, comprising the following steps: i. sterilizing the insects, ii. grinding the insects, iii. cooling to a temperature less than or equal to 4°C, said cooling step comprising a dilution-cooling sub-step by adding water at a temperature between 4°C and 15°C, in which steps i. to iii. are carried out continuously.

7. Method according to claim 6, comprising a bleaching step prior to the sterilization step.

8. A method according to any one of claims 1 to 7, wherein the insect pulp is stored and / or frozen.

9. Insect pulp comprising: - a dry matter content of between 20 and 30% by weight expressed in relation to the total weight of the insect pulp, - a protein content of at least 45% by weight expressed in relation to the dry weight of the pulp, - a lipid content of at least 20% by weight expressed in relation to the dry weight of the pulp, and - a microorganism content of less than 1000 cfu / g.

10. Pulp according to claim 9, comprising a dry matter content of between 23 and 27% by weight, the percentage by weight being expressed relative to the total weight of the pulp.

11. Insect pulp according to claim 9 or 10, wherein the insects are beetles.

12. Use of the insect pulp according to any one of claims 9 to 11, for the preparation of an animal feed.

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