EP3562317A1

EP3562317A1 - Method for treating insects, in which the cuticles are separated from the soft part of the insects, and the soft part is then separated into three fractions

Info

Publication number: EP3562317A1
Application number: EP17825881.0A
Authority: EP
Inventors: Sophie Laurent; Thibault SARTON DU JONCHAY; Jean-Gabriel LEVON; Cecilia SOCOLSKY; Lorena SANCHEZ; Nathalie BEREZINA; Benjamin ARMENJON; Antoine Hubert; Corentin LE BERRE; Adam KIRECHE; Hella TOKOS; Bénédicte LORRETTE
Original assignee: Ynsect SAS
Current assignee: Ynsect SAS
Priority date: 2016-12-28
Filing date: 2017-12-28
Publication date: 2019-11-06
Also published as: KR20190099298A; AU2017385712A1; EP3562316A1; AU2017385712B2; CN110099571A; JP7127030B2; MX2019007884A; AU2017387972B2; US11998029B2; RU2019123582A3; AU2017387972A1; US20200107560A1; FR3060947A1; BR112019013482A2; CN110099573A; US20220174989A1; KR20190099297A; KR20230124761A; WO2018122476A1; AU2023201702A1

Abstract

The invention relates to a method for treating insects, comprising the separation of the cuticles from the soft part of the insects, the maturation of the soft part of the insects, followed by the separation of the soft part of the insects into an oil fraction, a solid fraction and an aqueous fraction. The invention further relates to powders, in particular a powder obtainable by the method of treating insects according to the invention, and to the use of these powders in food.

Description

METHOD OF TREATING INSECTS COMPRISING THE SEPARATION OF CUTICLES FROM THE MOLLE PART OF INSECTS THEN SEPARATING THE MOLLE PART INTO THREE FRACTIONS

The present invention relates to a method of treating insects. The invention also relates to powders, in particular a powder that can be obtained by the insect treatment method according to the invention, and the use of these powders in food, especially in animal feed.

Powders made from animals have long been used in animal feed.

One of the most used powders is fish meal, which is one of the main sources of protein in animal feed. Fishmeal is very rich in animal protein (rich in amino acids such as lysine and methionine) that are easy to digest. A growing demand accompanied by a limited supply has resulted, in particular, in significantly increasing its price. Thus, there is a strong demand for alternative sources of high quality and, to the extent possible, renewable protein that could be used in animal feed.

In recent years, it has been proposed to use flour prepared from insects as a substitute for fishmeal.

Insect flours offer natural protein sources for replacement and the possibility of mass production with minimal ecological footprint. In particular, some beetles such as Tenebrio molitor, have the advantage of being suitable for intensive mass production.

By way of example, application WO2016 / 108037 describes in particular a coleopteran powder comprising at least 67% by weight of proteins and at least 5% by weight of chitin, which can be used in animal feed.

In the context of the present application, "chitin" means any type of chitinic derivative, that is to say of a polysaccharide derivative comprising N-acetylglucosamine units and D-glucosamine units, in particular the chitin-polypeptide polymers (sometimes referred to as "chitin-polypeptide composite"). These copolymers may also be associated with pigments, often of the melanin type.

Chitin is the second most synthesized polymer in the world after cellulose. Indeed, chitin is synthesized by many species of the living world: it is partly the exoskeleton of crustaceans and insects and the side wall that surrounds and protects the fungi. More particularly, in insects, chitin thus constitutes 3 to 60% of their exoskeleton.

However, chitin is generally considered a compound difficult to digest by some animals.

There is therefore a need for powders made from insects that have a reduced chitin content.

The work of the inventors made it possible to demonstrate that it was possible to obtain such powders, when the insects from which these powders are prepared were subjected to a specific treatment.

The invention thus relates to a method of treating insects comprising the following steps:

cuticle separation from the soft part of insects and then

separating the soft part of the insects into an oily fraction, a solid fraction and an aqueous fraction.

"Insects" means insects at any stage of development, such as adult, larval, or pupal stage.

The cuticle is the outer layer (or exoskeleton) secreted by the epidermis of insects. It usually consists of three layers: the epicuticle, the exocuticle and the endocuticle.

The term "soft part" refers to the flesh (including muscles and viscera) and the juice (including body fluids, water and haemolymph) of the insects. In particular, the soft part does not consist in the juice of insects.

Advantageously, the insects used in the process according to the invention are in a larval stage.

Preferably, the insects used in the process according to the invention are edible.

Advantageously, the preferred insects for carrying out the process according to the invention are, for example, Coleoptera, Diptera, Lepidoptera, Isoptera, Orthoptera, Hymenoptera, Boletoptera, Hemiptera, Heteroptera, Ephemeroptera and moptera, preferably beetles, Diptera, Orthoptera, Lepidoptera or mixtures thereof, more preferably beetles.

The Coleoptera preferentially used in the process according to the invention belong to the families Tenebrionidae, Melolonthidae, Dermestidae, Coccinellidae, Cerambycidae, Carabidae, Buprestidae, Cetoniidae, Dryophthoridae, or mixtures thereof.

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

The oily fraction has a lipid content greater than or equal to 90%, preferably greater than or equal to 95%, even more preferably greater than or equal to 99% by weight relative to the total weight of the oily fraction.

It should be noted that in the context of the present application, and unless otherwise stated, the ranges of values indicated are inclusive.

The solid fraction has a dry matter content of between 45 and 65% by weight relative to the total weight of solid fraction.

The aqueous fraction has a carbohydrate content of between 15 and 40% by weight, preferably between 20 and 30% by weight, relative to the total dry weight of the aqueous fraction.

At the end of the step of separating the soft part, and before any concentration thereof, the aqueous fraction has a solids content of less than or equal to 20% by weight, preferably less than or equal to 15% by weight. % by weight on the total weight of aqueous fraction.

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

A filter press is composed of filter cloths, and allows separation according to the pressure filtration principle.

According to a second embodiment, the separation of cuticles from the soft part of the insects is carried out using a band separator.

By band separator is meant a device for separating the solid portion of the soft portion of a product, and which comprises a clamping band (or pressing belt) and a perforated drum.

The separation of the cuticles from the soft part of the insects is more fully described in step 2 of the detailed insect treatment method according to the invention hereinafter.

This separation of the cuticles from the soft part of the insect makes it possible in particular to separate the chitin from the soft part. Indeed, the cuticles obtained at the end of this separation step has a high chitin content of the order of 10 to 30% by weight on the total weight of cuticles, as indicated below. In particular, the step of separating cuticles from the soft part is carried out without any prior step of grinding insects, particularly in the form of particles, has been performed.

Also, the separation of the soft portion of the insects into an oily fraction, a solid fraction and an aqueous fraction is more fully described in step 4 of the detailed insect treatment method according to the invention hereinafter.

The insect treatment method according to the invention may comprise a slaughtering step prior to the step of separating the cuticles from the soft part.

Advantageously, following the slaughter stage 1, the insects are directly used for the implementation of step 2 of separating the cuticles from the soft part of the insects, that is to say that the insects are not subjected to no treatment, such as grinding, freezing or dehydration between step 1 and step 2.

This slaughtering step is more fully described in step 1 of the detailed method of treating insects according to the invention hereinafter.

Optionally, the insect treatment method according to the invention further comprises a step of maturation of the soft part of the insects, between the step of separating the cuticles from the soft part and the step of separating the soft part of the insects. insects in an oily fraction, a solid fraction and an aqueous fraction.

By "stage of maturation of the soft part of the insects", it is more particularly a step during which the soft part of the insects is subjected to agitation.

This step is more fully described in step 3 of the detailed insect treatment method according to the invention hereinafter.

In particular, the insect treatment method according to the invention may therefore comprise the following steps:

- separation of cuticles from the soft part of insects,

- the maturation of the soft part of the insects, then

Optionally, the insect treatment method according to the invention comprises a step of concentration of the aqueous fraction, to obtain a concentrated aqueous fraction.

This step is more fully described in step 5 of the detailed insect treatment method according to the invention hereinafter. Optionally, the insect treatment method according to the invention further comprises a step of mixing the solid fraction:

with all or part of the concentrated aqueous fraction; and or

- all or part of the cuticles,

to obtain a mixture.

This step is more fully described in step 6 of the detailed insect treatment method according to the invention hereinafter.

Preferably, the insect treatment method according to the invention comprises a step of drying the solid fraction or the mixture to obtain a dry solid fraction or a dry mixture, respectively.

This step is more fully described in step 7 of the detailed insect treatment method according to the invention hereinafter.

Preferably, the insect treatment method according to the invention further comprises a grinding step of the dry solid fraction or of the mixture

This step is more fully described in step 8 of the detailed insect treatment method according to the invention hereinafter.

More particularly, the process according to the invention is carried out without it being necessary to add a solvent, such as water. In particular, no dilution of the soft part is performed during the process according to the invention.

According to a preferred embodiment of the insect treatment method according to the invention, this is a process for preparing a powder, and especially an insect powder, and comprises the following steps:

i) the killing of insects;

ϋ) separation of cuticles from the soft part of insects;

iii) optionally, ripening of the soft part of the insects;

iv) separating the soft part of the insects into a solid fraction, an aqueous fraction and an oily fraction;

v) optionally, concentrating the aqueous fraction to obtain a concentrated aqueous fraction;

optionally, mixing the concentrated aqueous fraction and / or cuticles with the solid fraction to obtain a mixture; vii) drying the solid fraction obtained in step iv) or the mixture obtained in step vi) to obtain a dry solid fraction or a dry mixture; and viii) grinding the dry solid fraction or the dry mixture obtained in step vii).

Detailed method for treating insects according to the invention

• Step 1: Slaughtering insects

This slaughtering stage 1 may advantageously be carried out by thermal shock, such as boiling or bleaching. This step 1 makes it possible to kill the insects while lowering the microbial load (reduction of the risk of deterioration and health) and by inactivating the internal enzymes of the insects that can trigger an autolysis, and thus a rapid browning of these.

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

The quantity of water introduced during scalding is determined as follows: the ratio of the volume of water in ml to the weight in g of insect is preferably between 0.3 and 10, more preferably between 0 and 10. , 5 and 5, still more preferably between 0.7 and 3, even more preferably of the order of 1.

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

• Step 2: Separation of cuticles from the soft part of insects Step 2 aims to separate cuticles from the soft part of insects.

The separation of cuticles from the soft part of the insects can be carried out at using any type of suitable separator.

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

Advantageously, the filter press used in the insect treatment process according to the invention is a band-press filter.

A band press filter has two perforated clamping bands (also called "filter cloths"). The insects are placed between the two perforated clamping bands so as to press the soft part of the insects through the perforations of the clamping bands, while the solid part of the insects remain between the two perforated clamping bands.

Those skilled in the art are able to determine the diameter of the perforations of the clamping bands and the pressure to be exerted, allowing the cuticles to be separated from the soft part of the insects.

By way of example, mention may be made of the belt press filter (or "belt press") from the Flottweg company, or the band press filters from the company ATR Créations.

According to a second embodiment, the separation of cuticles from the soft part is carried out using a band separator.

By way of example, a belt separator may comprise a clamping band and a perforated drum, the clamping band surrounding at least a portion of the perforated drum.

The clamping band allows the application and application of the insects against the perforated drum so as to press the soft part of the insects through the perforations of the drum while the solid part of the insects (cuticles) remains. outside the drum.

The cuticles can then be recovered using a scraper knife. By way of example, band separators from Baader, such as 601 to 607 ("soft separator 601 to 607") band separators, or BFD Corporation's SEPAmatic® belt separators ( range 410 to 4000V).

Advantageously, the diameter of the perforations of the drum is between 0.5 and 3 mm, preferably between 1 and 2 mm.

Regarding the pressure, the skilled person is able to determine the pressure to be exerted for the separation of cuticles from the soft part of the insects. This insect separation step differs from a conventional pressing that can be achieved for example with a single-screw or twin-screw press in that it allows a separation (net) of the soft part and cuticles of insects and not a separation of a juice from a solid fraction.

Advantageously, the separation of cuticles from the soft part of the insects is carried out using a band separator.

The cuticles obtained in step 2 comprise between 10 and 30%, preferably between 15 and 25% by weight of chitin, on the total dry weight of cuticles.

The determination of the chitin content is carried out by extraction thereof. For example, a method for determining the chitin level that can be used is the ADAC 991.43 method.

Furthermore, the cuticles comprise less than 25%, preferably less than 10%, more preferably less than 5%, even more preferably less than 3% by weight of lipids on the total dry weight of the cuticles.

Methods for determining the fat content (lipids) are well known to those skilled in the art. By way of example and preferably, the determination of this content will be carried out according to the method of the EC regulation 152/2009.

Throughout the application, where no date is specified for a regulation, standard or directive, it is the regulation, standard or directive in effect on the filing date.

In addition, the cuticles comprise between 55 and 90%, advantageously between 60 and 85%, preferably between 65 and 80% by weight of proteins on the total dry weight of cuticles.

In the context of the present application, the term "proteins" refers to the amount of crude protein. Quantification of the crude proteins is well known to those skilled in the art. By way of example, mention may be made of the Dumas method or the Kjeldhal method. Preferably, the Kjeldhal method is used.

It should be noted, however, that this method is based on measuring the nitrogen content. Chitin contains nitrogen at a level of about 8%. As a result, the nitrogen content of chitin was deduced from the measured nitrogen content before conversion to obtain the protein content.

The cuticles comprise between 0.5 and 30%, advantageously between 1 and 20%, preferably between 5 and 15% by weight of carbohydrates on the total dry weight of cuticles.

The carbohydrate content was calculated by measuring the difference in carbohydrates. According to this method, the carbohydrate content is equal to the dry matter content to which the ash, protein and lipid content are subtracted.

In addition, the cuticles preferably comprise at least 0.08% by weight, more preferably at least 0.1% by weight, more preferably at least 0.12% by weight of trehalose on the total dry weight of cuticles.

The amount of trehalose is determined by GC-MS analysis. Such an analysis is more fully described in Example 1 below.

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

In addition, the soft part comprises at least 45%, preferably at least 48%, more preferably at least 50% by weight of protein on the total dry weight of the soft part.

• Step 3: Maturation of the soft part of insects

The soft part of the insects is then, optionally, stirred in a tank.

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

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

This step facilitates the separation of the soft part of the insects in step 4 below.

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

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

Advantageously, this maturation step is immediately followed by the step of separating the soft part into a solid fraction, an aqueous fraction and an oily fraction.

In particular, no further dilution step in a solvent such as water and / or heating is necessary to effect the separation into three fractions.

On the contrary, as shown in Example 3, such a dilution step has the effect of:

to prevent a good separation of the three fractions (solid, aqueous and oily), to degrade the properties of the three fractions, and

- generate significantly higher costs.

• Yielding of the soft part in a single fraction, an aqueous fraction and an oily fraction

This step aims to recover three fractions from the soft part of insects obtained in step 2 or 3, namely a solid fraction, an aqueous fraction, and an oily fraction.

According to a first embodiment, this step of separating the soft part is performed in two sub-steps.

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

In the second substep, the liquid fraction is subjected to centrifugation, so as to recover an oily fraction and an aqueous fraction.

Advantageously, in this second substep, a plate centrifuge is used.

According to a second embodiment of step 4, the soft part of the insects is subjected to decantation using a 3-phase decanter, so as to obtain directly an aqueous fraction, an oily fraction and a solid fraction.

Suitable 3-phase decanters are, for example, Tricanter® from Fiottweg, or 3-phase decanters from GEA, such as clarifier CA 225-03-33.

Advantageously, the separation of the soft part is performed according to the second embodiment.

Indeed, the use of a 3-phase decanter makes it possible to obtain particularly effective phase separation. More particularly, the solid fraction obtained has a high content of dry matter, the aqueous fraction has little insoluble sediment (from the solid fraction) and oil, and the oily fraction has little insoluble sediment (from the solid fraction ) and water.

· Step 5: Concentration of the aqueous fraction

The aqueous fraction obtained in step 4 is then optionally concentrated to obtain a concentrated aqueous fraction.

Advantageously, the concentration is carried out by evaporation.

Advantageously, the evaporation is carried out at a temperature of between 30 and 100 ° C., preferably between 60 and 80 ° C. Preferably, the evaporation is carried out at a pressure of between 50 and 1013 mbar, preferably at 1013 mbar.

The evaporation is preferably carried out for a period of between 5 and 20 minutes.

The concentration is preferably carried out using a falling film evaporator, a rising water plate evaporator, or a thin film evaporator.

This type of standard equipment can be used without encountering fouling problem, thanks to the small amount of sediment present in the aqueous fraction.

Generally, the aqueous fractions can not be concentrated beyond 42% dry matter, because they tend to gel (glue water) from this concentration.

In the case of the present invention, the aqueous fraction comprises soluble proteins of small size (at least 45%, preferably at least 60% of the soluble proteins of the aqueous fraction have a size of less than 550 g / mol, as more fully described hereinafter), which makes it possible to avoid gelling and thus to obtain an aqueous fraction with a high concentration of dry matter (up to 70%) and having a viscosity of less than 30,000 cPs (centipoise).

By "soluble proteins" is meant, among the crude proteins, those which are soluble in an aqueous solution whose pH is between 6 and 8, advantageously between 7.2 and 7.6.

When the term "proteins" is used in the present application, it refers to crude proteins.

Preferably, the aqueous solution is a buffer solution whose pH is between 6 and 8, advantageously between 7.2 and 7.6. Preferably, the buffer solution is an NaCl phosphate buffer solution, whose pH is equal to 7.4 +/- 0.2.

In addition, the concentration step of the aqueous fraction has a double interest because it allows:

a saving in steam: in the absence of the concentration step 5, the water should be evaporated during the drying step 7 described hereinafter, with a dryer whose specific steam consumption is greater than that of a concentrator as described above; and

- to avoid microbiological contaminations, thanks to a reduction of the volume and the osmotic pressure due to the high concentration in dry matter of the fraction concentrated aqueous

* Step 6 _.:. élanflgggg., dj lg! MJgue _"is. cpnce" ^ ed and / or.

cuticles with its solid fraction

All or part of the cuticles obtained in step 2 and / or all or part of the concentrated aqueous fraction obtained in step 5 can / may be optionally mixed with the solid fraction obtained in step 4 to obtain a mixed.

Advantageously, the mixture is homogenized so as to facilitate its subsequent treatment.

Mixers that can be used are, for example, conical screw mixers, such as those from the company Vrieco-Nauta®, or pendulum mixers, such as those from the company PMS.

It will be noted that, on average, for one kilogram of solid fraction obtained, 500 to 650 g of cuticles, for example approximately 550 g, and 250 to 350 g of aqueous fraction, for example approximately 300 g, are obtained.

·

mixture obtained in step 6

The solid fraction obtained in step 4 or the mixture obtained in step 6 can be dried to obtain a dry solid fraction or a dry mixture.

Advantageously, the drying is carried out using a disk dryer, a tubular dryer, a propeller dryer, a flash type dryer, a thin film dryer or an atomization dryer.

Preferably, the drying is carried out using a disk or tubular dryer.

Suitable tubular dryers are for example those of Tummers (Simon Dryers Technology).

Suitable disk dryers are, for example, those of Haarslev. The drying can be carried out between 1 and 10 hours, preferably between 3 and 5 hours.

Advantageously, the drying is carried out at a temperature between 60 and 225 ° C, preferably between 80 and 100 ° C.

Preferably, the evaporation is carried out at atmospheric pressure.

Step 8: Grinding of the dry solid fraction or of the dry mixture obtained in step 7

Following drying, grinding can be carried out and a powder is obtained. By "powder" is meant a composition in the form of particles. Preferably, the powder according to the invention is an insect powder, that is to say a powder prepared solely from insects and possibly water.

A mill such as a hammer mill or a cone mill (such as cone mills ("Kek cone mills") from Kemutec) can for example be used.

Advantageously, at the end of this grinding, the particle size is less than 0.5 cm (larger particle size observable using a microscope), preferably of the order of 1 mm. More particularly, the particle size is between 300 μm and 1 mm, more preferably between 500 and 800 μm.

When the powder is milled to a particle size acceptable for human or animal consumption, it may be referred to as "flour" and in particular "insect meal" ("insect meal"). By "particle size acceptable for human or animal nutrition", a particle size of between 100 μm and 1.5 mm is preferred, preferably between 300 μm and 1 mm, more preferably between 500 and 800 μm.

Depending on whether the optional steps 5 and / or 6 are / are implemented or not, different powders can be obtained, namely:

a powder resulting solely from the solid fraction (step 6 not implemented);

a powder resulting from mixing the solid fraction and all or part of the cuticles;

a powder resulting from the mixing of the solid fraction and all or part of the concentrated aqueous fraction;

a powder resulting from the mixing of the solid fraction, all or part of the cuticles and all or part of the concentrated aqueous fraction.

The invention also relates to the products resulting from the process according to the invention.

The invention further relates to a solid fraction obtainable by the insect treatment method according to the invention.

The invention also relates to a solid fraction comprising at least 71% by weight of proteins and between 0.1 and 2% by weight of chitin, the percentages by weight being indicated on the total dry weight of the solid fraction.

Preferably, the solid fraction comprises at least 73% by weight, more preferably at least 74% by weight, still more preferably at least 75% by weight of proteins, the percentages by weight being indicated on the total dry weight of solid fraction. Advantageously, the solid fraction comprises between 0.5 and 1, 7% by weight of chitin on the total dry weight of solid fraction.

Advantageously, the solid fraction comprises between 5 and 17% by weight of lipids, preferably between 10 and 15% by weight of lipids, on the total dry weight of solid fraction.

Preferably, the solid fraction comprises between 1 and 10% by weight, preferably between 2 and 6% by weight of ash, on the total dry weight of solid fraction.

The method of determining the ash content is well known to those skilled in the art. Preferably, the ashes have been determined according to the method falling under EC Regulation 152/2009 of 27-01-2009.

In addition, the solid fraction preferably comprises between 5 and 15% by weight, more preferably between 7 and 13% by weight of carbohydrates on the total dry weight of solid fraction.

More particularly, the solid fraction preferably comprises at least 0.2% by weight, more preferably at least 0.3% by weight, still more preferably at least 0.35% by weight, still more preferably at least 0.5% by weight. by weight and even more preferably at least 0.7% by weight of trehalose on the total dry weight of solid fraction.

Moreover, the digestibility of proteins in humans and animals is strongly conditioned by the size of the proteins. In animal nutrition, it is common to reduce the size of proteins, to facilitate the digestion of animals. This reduction in the size of the proteins is generally done by hydrolysis processes (for example enzymatic), the implementation of which is particularly expensive.

The solid fraction comprises soluble proteins whose size is sufficiently small to facilitate the digestion of the animals.

Advantageously, at least 75%, preferably at least 80%, more preferably at least 85% of the soluble proteins of the solid fraction have a size less than or equal to 12400 g / mol.

More particularly, at least 55%, preferably at least 60%, more preferably at least 65% of the soluble proteins of the solid fraction have a size of less than 550 g / mol.

The invention also relates to an aqueous fraction that can be obtained by the insect treatment method according to the invention.

The invention further relates to an aqueous fraction comprising at least 48% by weight of proteins, at least 2% by weight of trehalose, and having a content of lipids less than 7% by weight, the percentages by weight being indicated on the total dry weight of the aqueous fraction.

Preferably, the aqueous fraction comprises at least 55% by weight, more preferably at least 60% by weight, still more preferably at least 65% by weight of protein, relative to the total dry weight of the aqueous fraction.

Advantageously, the aqueous fraction comprises at least 2.5% by weight, more preferably at least 3% by weight of trehalose on the total dry weight of the aqueous fraction.

Preferably, the aqueous fraction has a lipid content of less than 6% by weight, more preferably less than 4% by weight, even more preferably less than 2% by weight, relative to the total dry weight of the aqueous fraction.

Advantageously, the aqueous fraction comprises between 5% and 20% by weight of ash, preferably between 7% and 15% by weight of ash on the total dry weight of the aqueous fraction.

In addition, the aqueous fraction comprises less than 2% by weight of insoluble sediments, preferably less than 1% by weight of insoluble sediments, preferably less than 0.5% by weight of insoluble sediments on the total weight of the aqueous fraction.

The aqueous fraction does not contain chitin.

Similar to the solid fraction, the aqueous fraction has soluble proteins whose size is sufficiently small to facilitate digestion of the animals.

Advantageously, at least 90%, preferably at least 95%, more preferably at least 97% of the soluble proteins of the aqueous fraction have a size less than or equal to 12400 g / mol.

More particularly, at least 45%, preferably at least 50%, more preferably at least 53%, even more preferably at least 60% of the soluble proteins of the aqueous fraction have a size of less than 550 g / mol.

More particularly, the aqueous fraction has a dry matter content of between 5 and 15% by weight relative to the total weight of the aqueous fraction.

When concentrated, the concentrated aqueous fraction has a dry matter content of between 55 and 75% by weight relative to the total weight of concentrated aqueous fraction.

The invention also relates to a concentrated aqueous fraction that can be obtained by the insect treatment method according to the invention, said process treatment then having the optional step of concentration.

The invention further relates to an oily fraction obtainable by the insect treatment method according to the invention.

The invention also relates to a powder obtainable by the insect treatment method comprising the following steps:

- separation of cuticles from the soft part of insects,

separating the soft part of the insects into an oily fraction, a solid fraction and an aqueous fraction,

optionally, the concentration of the aqueous fraction,

optionally, the mixing of the solid fraction with:

all or part of the concentrated aqueous fraction; and or

- all or part of the cuticles,

to obtain a mixture,

drying the solid fraction or the mixture to obtain a dry solid fraction or a dry mixture, respectively;

- Grinding the dry solid fraction or dry mixture.

This insect treatment method may further comprise one or more of the features described above.

The invention relates more particularly to a powder that can be obtained by the process for preparing a powder, and in particular an insect powder, according to the invention, as described above.

As indicated above, depending on whether the optional steps 5 and / or 6 of the insect treatment process according to the invention, namely the concentration step of the aqueous fraction and the mixing step of all or part of the cuticle and / or all or part of the concentrated aqueous fraction, with the solid fraction, is / are or is / are not used and, where appropriate, according to the conditions of their implementation, different powders can be obtained.

The invention also relates to a powder, and in particular an insect powder, comprising at least 71% by weight of proteins and between 0.1 and 4% by weight of chitin, the percentages by weight being indicated on the total dry weight of powder.

Preferably, this powder has a protein content greater than or equal to 72% by weight, more preferably greater than or equal to 74% by weight, still more preferably greater than or equal to 75% by weight, relative to the total dry weight of powder. More particularly, this powder has a chitin content of between 0.5 and 3% by weight, more preferably between 0.8 and 2% by weight, even more preferably between 0.8 and 1.7% by weight on the total dry weight of powder.

Preferably, this powder comprises between 5 and 20% by weight, preferably between 7 and 17% by weight of lipids, relative to the total dry weight of powder.

More particularly, this powder comprises between 1 and 10% by weight, preferably between 2 and 6% by weight of ash, on the total dry weight of powder.

In addition, this powder preferably comprises between 3 and 20% by weight of carbohydrates on the total dry weight of powder.

More particularly, this powder preferably comprises at least 0.1% by weight, more preferably at least 0.2% by weight of trehalose on the total dry weight of powder.

When the optional steps 5 and / or 6 are / are not implemented, a powder, and in particular an insect powder, resulting solely from the solid fraction is obtained.

This powder comprises at least 71% by weight of proteins and between 0.1 and 2% by weight of chitin, the percentages by weight being indicated on the total dry weight of powder.

Preferably, this powder has a protein content greater than or equal to

72% by weight, more preferably greater than or equal to 74% by weight, still more preferably greater than or equal to 75% by weight, relative to the total dry weight of powder.

More particularly, this powder has a chitin content of between 0.5 and 1.7% by weight of chitin, based on the total dry weight of powder.

Preferably, this powder comprises between 5 and 17% by weight, preferably between 10 and 15% by weight of lipids, relative to the total dry weight of powder.

In addition, this powder preferably comprises between 5 and 15% by weight, more preferably between 7 and 13% by weight of carbohydrates on the total dry weight of powder.

More particularly, this powder preferably comprises at least 0.2% by weight, more preferably at least 0.3% by weight, still more preferably at least 0.35% by weight of trehalose on the total dry weight of powder.

When steps 5 and 6 of the process according to the invention are implemented, a powder resulting from the mixing of the solid fraction, all or part of the cuticles and all or part of the concentrated aqueous fraction can also be obtained.

The invention therefore also relates to a powder, and in particular an insect powder, comprising at least 65% by weight of proteins, at least 10% by weight of carbohydrates and between 0.1 and 2% by weight of chitin, the percentages by weight being indicated on the total dry weight of powder.

Preferably, this powder has a protein content greater than or equal to 70% by weight, more preferably greater than or equal to 74% by weight, relative to the total dry weight of powder.

More particularly, this powder has a chitin content of between 0.2 and 1.5% by weight, more preferably between 0.5 and 1.3% by weight, relative to the total dry weight of powder.

Preferably, this powder has a carbohydrate content greater than or equal to 12% by weight, more preferably greater than or equal to 14% by weight, relative to the total dry weight of powder.

More particularly, this powder preferably comprises at least 0.7% by weight, more preferably at least 0.9% by weight, even more preferably at least 1% by weight, and even more preferably at least 1.2% by weight. of trehalose on the total dry weight of powder.

Preferably, this powder comprises between 5 and 15% by weight, preferably between 7 and 13% by weight of lipids, relative to the total dry weight of powder.

More particularly, this powder comprises between 3 and 10% by weight, preferably between 4 and 8% by weight of ash, relative to the total dry weight of powder.

The residual moisture content of the powders according to the invention is between 2 and 15%, preferably between 5 and 10%, more preferably between 4 and 8%. This humidity level can for example be determined according to the method resulting from the EC Regulation 152/2009 of 27-01-2009 (103 ° C / 4 h).

Advantageously, the proteins of the powders according to the invention have a digestibility greater than or equal to 85% by weight relative to the total weight of crude proteins.

Digestibility is a pepsic digestibility measured by the method described in Directive 72/199 / EC.

Preferably, the digestibility is greater than or equal to 88%, more preferably greater than or equal to 92%.

The invention further relates to the use of an aqueous fraction according to the invention, a concentrated aqueous fraction according to the invention, or powder comprising at least 65% of proteins, at least 10% by weight of carbohydrates and between 0.1 and 2% by weight of chitin according to the invention described above, as a flavor, advantageously in animal feed.

The invention finally relates to the use of a powder according to the invention in food, preferably in animal feed.

Other features and advantages of the invention will become apparent in the examples which follow, given by way of illustration, with reference to the figures:

- Figure 1 is a diagram illustrating the detailed method of insect treatment according to the invention;

- Figure 2 includes two photographs of the soft part, firstly at the outlet of the reactor after the maturation step (Figure A) and secondly, after centrifugation to separate the phases (Figure B);

- Figure 3 is a standard curve used to perform the determination of trehalose;

- Figure 4 is a diagram illustrating the moisture content of the oily fraction obtained by the process according to the invention and the oily fraction obtained by comparative methods;

FIG. 5 is a diagram illustrating the sediment content of the oily fraction obtained by the process according to the invention and of the oily fraction obtained by comparative methods;

FIG. 6 is a diagram illustrating the peroxide number of the oily fraction obtained by the process according to the invention and of the oily fraction obtained by a comparative method;

- Figure 7 is a diagram illustrating the dry matter content of the aqueous fraction obtained by the process according to the invention and the aqueous fraction obtained by comparative methods;

- Figure 8 is a diagram illustrating the sediment content of the aqueous fraction obtained by the process according to the invention and the aqueous fraction obtained by a comparative method;

FIG. 9 is a diagram illustrating the percentage of emulsion present in the aqueous fraction obtained by the process according to the invention and in the aqueous fraction obtained by a comparative method;

FIG. 10 is a diagram illustrating the percentage (as a percentage of dry matter) of lipids present in the aqueous fraction obtained by the process according to the invention and in the aqueous fraction obtained by comparative methods;

FIG. 11 is a diagram illustrating the pepsic digestibility of the proteins of the aqueous fraction obtained by the process according to the invention and that of the proteins of the aqueous fraction obtained by comparative methods;

FIG. 12 is a diagram illustrating the trehalose content of the aqueous fraction obtained by the process according to the invention and of the aqueous fraction obtained by comparative methods;

Figure 13 comprises three photographs illustrating the color of the aqueous fraction obtained by the process according to the invention and that of the aqueous fraction obtained by comparative methods;

Figure 14 is a diagram illustrating the trehalose content of the solid fraction obtained by the process according to the invention and the solid fraction obtained by comparative methods;

FIG. 15 is a diagram illustrating the percentage of water-soluble part of the solid fraction obtained by the process according to the invention and of the solid fraction obtained by comparative methods;

Figure 16 is a diagram illustrating the percentage of soluble portion in the mobile phase of the solid fraction obtained by the process according to the invention and the solid fraction obtained by comparative methods; and

17 is a diagram illustrating the distribution of the size of the proteins in the solid fraction obtained by the process according to the invention and in the solid fraction obtained by comparative methods.

EXAMPLE 1 Insect Treatment Process According to the Invention

Tenebrio molitor larvae were used. On receipt of the larvae, they can be stored at 4 ° C for 0 to 15 days in their breeding tanks before slaughter without major degradation. The weight of the larvae (age) used is variable and therefore their composition may vary, as illustrated in Table 1 below:

biomass

(insects) mg 23 35 58 80 108 154

Dry matter% ^* 34 34 34.2 37.9 39.6 39.5

Ashes% * 1, 59 1, 52 1, 6 1, 75 1, 67 1, 43 Crude protein% * 22.6 22.2 22 23.2 23.1 23.2

Lipids% * 6.62 6.88 7.98 10.3 10.9 11, 7

^* % Is expressed as dry weight on wet weight of larvae.

Table 1: Biochemical composition of larvae of Tenebrio molitor according to their weight.

• Step 1: Slaughtering insects

Live larvae (+ 4 ° C to + 25 ° C) are conveyed in a thickness of between 2 and 10 cm, on a perforated belt (1 mm) to a bleaching chamber. The insects are thus bleached with steam (nozzles or steam bed) at 98 ° C under forced ventilation or with water at 92-95 ° C (spray nozzles) or in mixed mode (water + steam). The residence time in the bleaching chamber is between 5 seconds and 15 minutes, ideally 5 minutes.

The temperature of the larvae at the bleaching outlet is between 75.degree.

98 ° C.

• Step 2: Separation. The moistened part of the insect cuticles are conveyed to the feed hopper of a band separator to separate cuticles from the soft part of the larvae.

Advantageously, the separation takes place immediately after slaughtering so that the larvae do not have time to cool to room temperature.

The band separator used is a 601 band separator from Baader.

The diameter of the perforations of the drum is 1, 3 mm.

The soft part of the insects is recovered in a tank.

The cuticles are recovered using a scraper knife.

Determination of the amount of trehalose in cuticles

The amount of trehalose in the cuticles recovered in step 2 was measured as follows:

Trehalose is analyzed by GC-MS.

Temperature program: 150 ° C, followed by a ramp at 10 ° C / min up to 260 ° C, after 5 minutes at this temperature, a ramp of 25 ° C / min up to 310 ° C and maintenance of this temperature for 2 minutes. Injector temperature: 280 ° C, interface: 250 ° C, the split ratio is 10, the injection volume is 1 pL. For example, a sH-RXI-5mS column, 30m x 0.25mm x 0.25μm is used.

The preparation of the sample for analysis is carried out as follows: a precise quantity of the sample (between 10 and 300 mg) is weighed into a Falcon tube, 9.75 ml of methanol are added thereto and 250 μl of a solution are added. standard internal (myo-inositol, 25 μg / mL) in DMSO. The mixture is stirred at 80 ° C. for 10 minutes, 100 μl of BSTFA are then added and the reaction mixture is stirred for a further 30 minutes at room temperature, 1 ml of acetonitrile is then added and the sample thus prepared is injected onto a GC-MS device.

The amount measured is 1.2 mg trehalose per g dry matter.

* Step 3: Maturation of the soft part of insects

The soft part of the insects is left to rest in the recovery tank of step 2, with stirring for 1 hour and at a temperature of about 90 ° C.

• Step 4; Separation of the soft part a solid fraction, an aqueous fraction and an oily fraction

The soft part is then separated into three fractions using a three-phase decanter. The decanter used is Tricanter® Z23 from Flottweg.

Conditions of separation:

- Flow: up to 500Kg / h;

- Vt bowl: 4806 t / mm (3000G);

Y min: 5% (1.4 mm).

Three fractions are obtained at the end of this separation phase: an oily fraction, a solid fraction, and an aqueous fraction.

These fractions have the characteristics indicated in the following Table 2:

^* Mean scores calculated on several samples of each fraction, expressed on the dry matter%

Table 2: Characteristics of the oily fraction, the solid fraction and the aqueous fraction.

Determination of the size of the soluble proteins of the solid fraction and the aqueous fraction

Preparation of the solid sample (solid fraction): 30 mg of the sample are solubilized in 1 L of mobile phase and filtered using the chromafil xtra filter PES-45/25.

Preparation of the liquid sample (aqueous fraction): 400 μl are solubilized in 1600 μl. of the mobile phase and filtered using the filter Chromafil xtra PES-45/25, just before the injection. 1.5 ml of the sample thus prepared are centrifuged for 15 minutes at 12000 rpm (10625 g).

The conditions of implementation of the chromatography (HPLC Nexera XR of Shimadzu) are the following: the column used is a Superdex Peptide GL 10/300 (GE Healthcare), the detection is carried out by a DAD detector at 215 nm, the speed of the mobile phase is 0.3 mL / min and is composed of ACN (acetonitrile) / H ₂ C7TFA (trifluoroacetic acid) (30/70 / 0.1), the analysis is carried out at 25 ° C.

The size distribution of the soluble proteins of the solid fraction is shown in Table 3 below:

Molecular weight (kDa)%

> 12.4 13.8

12.4 - 6.5 14

6.5 - 1, 4 3.8

1, 4 - 0.55 2.1

<0.55 67.3

Table 3: Distribution of the size of the soluble proteins in the solid fraction The size distribution of the soluble proteins of the aqueous fraction is presented in Table 4 below:

Molecular weight (kDa)%

> 12.4 2.7

12.4 - 6.5 13.4

6.5 - 1, 4 19

1, 4 - 0.55 11, 5

<0.55 53.4

Table 4: Distribution of the size of the soluble proteins in the aqueous fraction Determination of the amount of trefoil in the solid fraction and the aqueous fraction

The amount of trefoil in these fractions was measured as follows:

The tre atose is analyzed by GC-S.

Temperature program: 150 ° C, followed by a ramp at 10 ° C / min up to 260 ° C, after 5 minutes at this temperature, a ramp of 25 ° C / min up to 310 ° C and maintenance of this temperature for 2 minutes. Injector temperature: 280 ° C, interface: 250 ° C, split ratio is 10, injection volume is 1 pL

The preparation of the sample for analysis is carried out as follows: a precise quantity of the sample (between 10 and 300 mg) is weighed into a Falcon tube, 9.75 ml of methanol are added thereto and 250 μl of a solution are added. of internal standard (myo-inositol, 25 μg / mL) in DMSO. The mixture is stirred at 80 ° C. for 10 minutes, 100 μl of BSTFA are then added and the reaction mixture is stirred for a further 30 minutes at room temperature, 1 ml of acetonitrile is then added and the sample thus prepared is injected onto a GC-MS device.

The amount measured in the solid fraction is 3.82 mg of trehalose per g of dry matter.

The amount measured in the aqueous fraction is 33.2 mg of trefoil per g of dry matter.

In addition, the aqueous fraction has less than 1% by weight of insoluble sediments on the total weight of the aqueous fraction.

Step 5: Concentration of the aqueous fraction

The aqueous fraction obtained in step 4 is then concentrated by evaporation, using a falling-film evaporator.

The concentrated aqueous fraction obtained has a solids concentration of about 65%.

• Step 6 (optional): Mixing the iaaueusgjgoncentrée fraçjic and / or cuticles with the solid fraction

Step 6 has not been implemented in this example.

• Step 7: Drying the solid fraction

The solid fraction obtained in step 4 is dried using a disk dryer from Haarslev for 5 hours in order to obtain a dry solid fraction or a dry mixture. From a microbiological point of view, the solid fraction contains less than 10 CFU / g of enterobacteria.

• Step 8: Grinding

The dry solid fraction is finally milled using a continuous hammer mill (6 reversible mobile - 8 mm thick). The mill is fed by a hopper with flow control flap (180kg / h). The perforated grid used to control the grain size at the outlet is 0.8 mm. The rotation speed of the motor is 3000 rpm (electric motor, power consumption 4kW (5.5 hp)).

The characteristics of an insect powder obtained are presented in Table 5 below.

^* The percentages given are percentages by weight on the total dry weight of the insect powder.

Table 5: Characteristics of an insect powder obtained in Example 1. EXAMPLE 2 Insect treatment method according to the invention

Steps 1 to 5 were implemented as described in the Example

1.

•

and cuticles with the solid fraction

The totality (100%) of the concentrated aqueous fraction obtained in step 5, as well as 0.05% by weight of the cuticles recovered in step 2, were mixed with all of the solid fraction obtained in step 4 , to obtain a mixture.

A conical screw mixer from Vrieco-Nauta® was used.

• Step 7: Drying the mixture

The mixture obtained in step 6 is dried using a disk dryer from Haarslev for 5 hours in order to obtain a dry mixture.

From a microbiological point of view, the dry mixture contains less than 10 CFU / g of enterobacteria.

• Step 8: Grinding

The dry mixture is finally milled using a continuous hammer mill (6 reversible mobile - 8 mm thick). The mill is fed by a hopper with flow control flap (180kg / h). The perforated grid used to control the grain size at the outlet is 0.8 mm. The rotation speed of the motor is 3000 rpm (electric motor, power consumption 4kW (5.5 hp)).

The characteristics of an insect powder obtained are presented in

Table 6 below.

* The percentages given are percentages by weight on the total dry weight of the insect powder.

Table 6: Characteristics of the insect powder obtained in Example 2.

EXAMPLE 3 Process According to the Invention and Comparative Methods I. Preparation of Samples

The process according to the invention for converting Tenebrio molitor larva pulp into oil (oily fraction or "TMO" for Tenebrio Molitor Oil), in aqueous phase (aqueous fraction or "SW" for Stick Water) and in solid proteins (fraction solid or "SPC" for Solid Protein Cake) and a comparative method have been reproduced.

The objective is to compare the quality of the products obtained by the two processes.

1. Method according to the invention

The larvae are initially bleached (parboiled) and then the cuticles of the larvae are separated from the soft part ("decutilated") through a band separator of the Baader brand.

8 kg of soft part resulting from the separation step is then sent for maturation in a pilot reactor with a capacity of 10 liters, said reactor being preheated to 50 ° C., with mechanical stirring at 350 rpm to guarantee a homogenization at the heart of the soft part. After a gradual rise in temperature of the soft part, the temperature is directly regulated in the mass thereof at 90 ° C. After one hour of heating at 90 ° C, the reactor is emptied. The heated soft part is then separated. The use of a tricantor is not possible at the laboratory scale, the soft part is centrifuged at 10000 g for 15 minutes to separate the different phases obtained (see Figure 2). Each phase (TMO, SW and SPC) is collected manually and stored at -20 ° C pending physico-chemical analyzes. 2. Comparative method

8 kg of soft part resulting from the separation step are used. This soft part came from the same batch of soft part as that used for the process according to the invention.

The comparative method differs from that according to the invention in two steps:

at the end of the separation, an additional step of coagulation of the soft part is carried out starting from 4 kg of soft part, in a pilot reactor, with stirring (350 revolutions / min) with a temperature of the walls of the fixed reactor at 100 ° C for 20 minutes; then

- The soft part is diluted by adding water and heated. Two dilutions of the soft part were made for these tests, 1: 0.5 (m / m, mass / mass) and 1: 0, 75 (m / m). Specifically, a volume of water at 50 ° C (2 liters or 3 liters depending on the dilution) is added to the pilot reactor. The regulation of the temperature in the pulp mass is carried out at 90 ° C. for one hour and then the reactor is emptied. The diluted soft part is then centrifuged under the same conditions as above and the 3 phases collected and stored at -20 ° C pending physicochemical analyzes.

II. Sample analyzes

Determination of the dry matter of the samples

The dry matter of TMO, SW and SPC is determined by drying to constant mass at 105 ° C according to ISO 6496. The difference in mass of the product before and after drying serves as a measure for the dry matter content. These contents are expressed as a percentage of mass. The moisture content is obtained by subtraction of the dry matter to the value 100.

Determination of the peroxide value in TMO

The peroxide number is determined according to the French standard NF EN ISO 3960 (June 2010) and expressed in MEQ of active oxygen / kg of oil.

Sediment content of TMO and SW

The filter used is a stainless steel sieve of pore 50 μm, previously tared. Sediment quantification is performed after 300 mL of TMO or 750 mL of SW (750 mL) is passed by weighing the residues in the sieve.

In the case of SW, the sediment dry matter is then determined as previously described. Evaluation of emulsion in Sa SW

The evaluation of the emulsion in the SW is carried out after centrifugation of 50 ml of SW collected. Collection of the emulsion (supernatant) is performed after placing the tubes at -20 ° to facilitate separation. The emulsion is then weighed and the result is expressed as a percentage of emulsion in the stick water.

Determination of fat in the SW

The determination of the fat or lipids in the samples of SW is carried out by extraction with petroleum ether after hydrolysis according to the regulation CE 152/2009. The amount of lipids is related to the dry matter of the sample in question (SW or SPC).

Determination of the pepsic digestibility of SW

The pepsic digestibility is determined on the SW according to Directive 72/199 / EC, without degreasing.

Determination of trehalose in SW and SPC

Trehalose is determined in SW and SPC after lyophilization. 40 mg of dry sample are extracted with 2 ml of DMSO for 1 hour, with stirring at 80 ° C. 250 μl of the extract are then mixed with 50 μl of myo-inositol, used as internal standard (1 g / l in DMSO). After homogenization, 100 μl of this mixture is derivatized with 100 μl of BSTFA-TMCS (99: 1) directly into GC-MS vial for 30 minutes at 60 ° C. Before injection, 600 μL of acetonitrile is added to GC-MS vial. The results are expressed in mg of trehalose / g dry using a standard range of trehalose carried out under the same conditions (FIG 3).

The derived extracts and the different standard range points are analyzed on a Shimadzu GC-MS-QP2010. The column used is a column SH-Rxi 5 ms (Schimadzu) of length 30 m, diameter 0.25 mm and fineness 0.25 p. The temperature program of the GC-MS is as follows: 100 ° C, followed by a ramp at 10 ° C / min up to 300 ° C held for 2 min.

The temperature of the injector is 280 ° C, that of the interface is 250 ° C, the split ratio is 10, the injection volume is 1 pL. The detection is carried out in SIM (Seiected Ion monitoring) mode with m / z specific for 305 for myoinositol and 361 for trehalose.

Measuring the color of the freeze-dried SW

The color has been compared to a color chart (RAL Classic K7 color chart) and characterized by the color code of this color chart. Determination of the soluble fraction of SPC

The experiments were performed from lyophilized SPCs. 1 g of sample is weighed (m) in a 50 ml tube previously weighed. 30 ml of water at ambient temperature are added and the tube is stirred (vortexed) for several minutes. After centrifugation, the supernatant liquid is removed and a second wash with 30 ml of water is carried out under the same conditions as the first. After removing the supernatant, the washed SPC pellet is placed in an oven at 60 ° C for 48 hours and then weighed. A control (unwashed SPC) is also placed in the oven to determine the percentage of actual dry matter and correct the initial weighing of samples before washing (% MS).

The percentage of soluble is determined as:

(mi x% MS) - mSPC washed dry

mi x% MS

Determination of the size of SPC soluble proteins

The size of the soluble proteins of the SPC is determined by steric exclusion chromatography.

40 mg of freeze-dried sample are solubilized in the mobile phase composed of acetonitrile / H ₂ O / TFA (trifluoroacetic acid) (30/70 / 0.1) in order to reach a concentration of 30 mg / mL and filtered at 45.degree. pm after centrifugation using the chromafil xtra filter PES-45/25. In parallel, the solubility of dry SW and SPC in the mobile phase is determined after drying the centrifugation residues in the oven.

The conditions for carrying out the chromatography carried out on a Shimadzu Nexera XR HPLC chain are as follows: the column used is a Superdex Peptide GL 10/300 (GE Healthcare), the detection is carried out by a DAD detector at 215 nm, the speed of the mobile phase (isocratic mode) is 0.3 mL / min. It is composed of acetonitrile / H 2 O / TFA (trifluoroacetic acid) (30/70/0, 1), the analysis is carried out at 25 ° C.

To determine the molecular weight distribution, four "standard" proteins of known molecular weight were first injected to define retention time intervals corresponding to different molecular weights. To analyze the molecular distribution of the samples, the total area of the chromatogram is first integrated at 215 nm and then separated into fractions corresponding to the five molecular weight categories. The results are expressed as a percentage of soluble proteins by molecular size categories.

The determination of the soluble part in the mobile phase is obtained analogously to that in water, but at 25% (temperature of the analysis). III. Results

1. Oily fraction

The results for the oily fraction are shown in Figure 4, 5 and 6.

Figures 4 and 5 relating to the moisture content and the sediment content show that the separation of the oily fraction is significantly better in the process according to the invention. Indeed, we see in these Figures a higher moisture content and sediment in the oily fraction according to the comparative method. This result is unexpected because it is well known to those skilled in the art that increasing a phase and / or heating usually improves the phase separation of a complex medium.

Moreover, in FIG. 6, it can be seen that the peroxide index of the oily phase obtained by the process according to the invention is lower than that of the oily phase obtained by the comparative method. The oily phase obtained by the process according to the invention therefore has a better preservation capacity. This is particularly advantageous since it makes it possible to avoid or reduce the addition of preservatives such as antioxidants. 2. Aqueous fraction

The results for the oily fraction are shown in Figures 7 to 13.

In Figure 7, there is a lower moisture content for the aqueous fraction obtained by the method according to the invention. Because of the dilution, the dry matter content is less important in the comparative process, which consequently requires greater equipment to recover the part (dry matter) which is of interest and a more intense use in terms of consumption of energy and water consumption in particular.

Figures 8 to 10 for sediment content, emulsion content and lipid content show that the separation of the aqueous fraction is significantly better in the process according to the invention. Indeed, there is shown in these figures a higher sediment content, emulsion and lipids in the oily fraction according to the comparative method. This result is unexpected because it is well known to those skilled in the art that increasing a phase and / or heating usually improves the phase separation of a complex medium.

We also note that: in FIG. 11, the pepsic digestibility of the proteins of the aqueous fraction obtained by the process according to the invention is better than that obtained by the comparative method; and

in Figure 12, the trehalose content of the aqueous fraction obtained by the process according to the invention is better than that obtained by the comparative method.

The presence of trehalose is interesting because trehalose has the ability to stabilize proteins and is therefore considered a natural biological preservative.

Finally, FIG. 13 proposes 3 photographs of the aqueous fraction obtained either by the process according to the invention, or by the comparative method, and lyophilized. The aqueous fraction obtained by the process according to the invention has a significantly lighter color. It follows from these figures that a different product is obtained by the method according to the invention. This difference in color can potentially be explained by the Maillard reaction which can take place during the coagulation and aqueous heating steps which are carried out in the comparative method. In the Maillard reaction, the small size proteins present in the medium are more likely to react, reducing the content of the medium to small proteins. This may in particular result in a decrease in the digestibility of the aqueous fraction.

3. Solid fraction

The results for the solid fraction are shown in Figures 14 to 17.

In Figure 14, it can be seen that the trehalose content of the solid fraction obtained by the process according to the invention is better than that obtained by the comparative method.

In Figure 15, it can be seen that the partly soluble content of the solid fraction obtained by the process according to the invention is better than that obtained by the comparative method. It is advantageous to have a significant content of partly soluble because the soluble portion facilitates the formulation of food and provides a better bioavailability, including releasing the smaller proteins.

In Figures 16 and 17, it is demonstrated that the content of small proteins, namely proteins less than 550Da is greater in the solid fraction obtained by the process according to the invention than in that obtained by the comparative method. It can thus be seen that small proteins are better preserved by the process according to the invention. This results in a higher solubility in water or mobile phase and in a larger proportion of small size proteins in this solid fraction, the comparative method likely contributing to the destruction of these products during the coagulation phases and of heating.

4. Energy consumption

Finally, energy consumption calculations were performed to compare the process according to the invention with the two comparative methods.

The comparative method at a dilution 1: 0.5 generates a cost 19.8 times higher than that of the process according to the invention and the comparative method at a dilution of 1: 0.75 generates a cost 20.2 times greater than that of the process according to the invention.

Claims

A method of treating insects comprising the steps of:

separation of cuticles from the soft part of insects,

- the maturation of the soft part of the insects, then

2. Method according to one of claims 1, wherein the cuticle separation of the soft part of insects is carried out using a filter press.

3. Method according to one of claims 1, wherein the cuticle separation of the soft part of the insects is performed using a band separator.

4. Solid fraction obtainable by the process according to any one of claims 1 to 3.

5. A solid fraction comprising at least 71% by weight of proteins and comprising between 0.1 and 2% by weight of chitin, the percentages by weight being indicated on the total dry weight of the solid fraction.

6. Process according to any one of claims 1 to 3, comprising a step of concentration of the aqueous fraction.

7. An aqueous fraction obtainable by the process according to any one of claims 1 to 3, 6.

8. Aqueous fraction comprising at least 48% by weight of proteins, at least 2% by weight of trehalose, and having a lipid content of less than 7% by weight, the percentages by weight being indicated on the total dry weight of the fraction aqueous.

9. Process according to any one of claims 1 to 3, 6, further comprising a step of mixing the solid fraction with:

all or part of the concentrated aqueous fraction; and or

- all or part of the cuticles,

to obtain a mixture.

The method of any one of claims 1 to 3, 9, comprising a step of drying the solid fraction or mixture to obtain a dry solid fraction or a dry mixture, respectively.

11. The method of claim 10, further comprising a step of grinding the dry solid fraction or dry mixture.

12. Powder obtainable by the process according to claim 11.

13. Powder comprising at least 71% by weight of protein and comprising between 0.1 and 4% by weight of chitin, the percentages by weight being indicated on the total dry weight of powder.

14. Powder comprising at least 65% by weight of protein, at least 10% by weight of carbohydrates and comprising between 0.1 and 2% by weight of chitin, the percentages by weight being indicated on the total dry weight of powder.

15. Use of an aqueous fraction according to one of claims 7 or 8, or the powder according to claim 14, as a flavor.

16. Use of a powder according to any one of claims 12 to 14 in the feed.

17. Use according to one of claims 5 or 16, in animal feed.