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

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.

Claims

1. Process for treating insects comprising the following steps: separating the cuticles from the soft part of the insects, maturation of the soft part of the insects, then separating the soft part of the insects into a fat fraction, a solid fraction and an aqueous fraction.

2. Process according to claim 1, in which separating the cuticles from the soft part of the insects is carried out using a filter press.

3. Process according to claim 1, in which separating the cuticles from the soft part of the insects is carried out using a belt separator.

4. Solid fraction obtainable by the process according to claim 1.

5. Solid fraction comprising at least 71% be weight proteins and comprising between 0.1 and 2% be weight chitin, the percentages by weight being indicated with respect to the total dry weight of the solid fraction.

6. Process according to claim 1, comprising a step of concentrating the aqueous fraction.

7. Aqueous fraction obtainable by the process according to claim 1.

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

9. Process according to claim 1, also 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, in order to obtain a mixture.

10. Process according to claim 1, comprising a step of drying the solid fraction or the mixture in order to obtain a dry solid fraction or a dry mixture, respectively.

11. Process according to claim 10, also comprising a step of grinding the dry solid fraction or the dry mixture.

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

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

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

15. Use as flavouring of an aqueous fraction according to claim 7.

16. Use of a powder according to claim 12, in nutrition.

17. Use according to claim 15, in animal nutrition.

18. Use as flavouring of the powder according to claim 14.

Description

[0230] Other characteristics and advantages of the invention will become apparent from the following examples, given by way of illustration, with reference to the figures:

[0231] FIG. 1 is a diagram illustrating the detailed process for treating insects according to the invention;

[0232] FIG. 2 comprises two photographs of the soft part, on the one hand at the outlet of the reactor after the maturation step (Figure A) and on the other hand, after centrifuging in order to separate the phases (Figure B);

[0233] FIG. 3 is a calibration curve used in order to carry out the trehalose assay;

[0234] FIG. 4 is a diagram illustrating the moisture content of the fat fraction obtained by the process according to the invention and of the fat fraction obtained by comparative processes;

[0235] FIG. 5 is a diagram illustrating the sediments content of the fat fraction obtained by the process according to the invention and of the fat fraction obtained by comparative processes;

[0236] FIG. 6 is a diagram illustrating the peroxide value of the fat fraction obtained by the process according to the invention and of the fat fraction obtained by a comparative process;

[0237] FIG. 7 is a diagram illustrating the dry matter content of the aqueous fraction obtained by the process according to the invention and of the aqueous fraction obtained by comparative processes;

[0238] FIG. 8 is a diagram illustrating the sediments content of the aqueous fraction obtained by the process according to the invention and of the aqueous fraction obtained by a comparative process;

[0239] 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 process;

[0240] FIG. 10 is a diagram illustrating the percentage (as 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 processes;

[0241] FIG. 11 is a diagram illustrating the pepsin 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 processes;

[0242] 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 processes;

[0243] FIG. 13 comprises three photographs illustrating the colour of the aqueous fraction obtained by the process according to the invention and that of the aqueous fraction obtained by comparative processes;

[0244] FIG. 14 is a diagram illustrating the trehalose content of the solid fraction obtained by the process according to the invention and of the solid fraction obtained by comparative processes;

[0245] FIG. 15 is a diagram illustrating the percentage of the water-soluble portion of the solid fraction obtained by the process according to the invention and of the solid fraction obtained by comparative processes;

[0246] FIG. 16 is a diagram illustrating the percentage of the portion, soluble in the mobile phase, of the solid fraction obtained by the process according to the invention and of the solid fraction obtained by comparative processes; and

[0247] FIG. 17 is a diagram illustrating the size distribution of the proteins in the solid fraction obtained by the process according to the invention and in the solid fraction obtained by comparative processes.

EXAMPLE 1

Process for Treating Insects According to the Invention

[0248] The larvae of Tenebrio molitor were used. Upon receipt of the larvae, they can be stored at 4° C. for 0 to 15 days in their rearing tanks without major degradation before being killed. The weight of the larvae (age) used is variable and as a result their composition can vary, as illustrated in Table 1 below:

TABLE-US-00001 TABLE 1 Biochemical composition of the larvae of Tenebrio molitor according to the weight thereof. Biomass (insects) mg 23 35 58 80 108 154 Dry matter %* 34 34 34.2 37.9 39.6 39.5 Ash %* 1.59 1.52 1.6 1.75 1.67 1.43 Crude proteins %* 22.6 22.2 22 23.2 23.1 23.2 Lipids %* 6.62 6.88 7.98 10.3 10.9 11.7 *The %s are expressed in dry weight with respect to the wet weight of larvae.

Step 1: Killing the Insects

[0249] Living larvae (+4° C. to +25° C.) are conveyed in layers with a thickness comprised between 2 and 10 cm, on a perforated conveyor belt (1 mm) to a blanching chamber. The insects are thus blanched with steam (steam nozzles or 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 blanching chamber is comprised between 5 seconds and 15 minutes, ideally 5 min.

[0250] The temperature of the larvae after blanching is comprised between 75° C. and 98° C.

Step 2: Separating the Soft Part from the Cuticles of the Insects

[0251] The larvae, once blanched, are conveyed to the feed hopper of a belt separator, in order to separate the cuticles from the soft part of the larvae.

[0252] Advantageously, the separation is performed immediately after killing so that the larvae do not have time to cool to ambient temperature.

[0253] The belt separator used is a belt separator 601 from Baader.

[0254] The diameter of the perforations of the drum is 1.3 mm.

[0255] The soft part of the insects is recovered in a tank.

[0256] The cuticles are recovered using a scraper blade.

Determining the Quantity of Trehalose of the Cuticles

[0257] The quantity of trehalose in the cuticles recovered in step 2 was measured in the following manner:

[0258] The trehalose is analyzed by GC-MS.

[0259] Temperature programme: 150° C., followed by an increase of 10° C./min up to 260° C., after 5 minutes at this temperature, an increase of 25° C./min up to 310° C. and maintaining this temperature for 2 minutes. Temperature of the injector: 280° C., of the interface: 250° C., the split ratio is 10, the injection volume is 1 μL. For example, an sH-RXI-5m5 column, 30 m×0.25 mm×0.25 μm is used.

[0260] Preparation of the sample for analysis is carried out in the following manner: a precise quantity of the sample (between 10 and 300 mg) is weighed in a Falcon tube, 9.75 mL of methanol is added thereto as well as 250 μL of an internal standard solution (myo-inositol, 25 μg/mL) in DMSO. The mixture is stirred at 80° C. for 10 minutes, 100 μL of BSTFA is then added and the reaction mixture is stirred for 30 additional minutes at ambient temperature, 1 mL of acetonitrile is then added and the sample thus prepared is injected on a GC-MS device.

[0261] The quantity measured is 1.2 mg of trehalose per g of dry matter.

Step 3: Maturation of the Soft Part of the Insects

[0262] The soft part of the insects is left to rest in the collecting tank of step 2, under stirring for 1 h and at a temperature of approximately 90° C.

Step 4: Separating the Soft Part into a Solid Fraction, an Aqueous Fraction and a Fat Fraction

[0263] The soft part is then separated into three fractions using a three-phase decanter. The decanter used is the Tricanter® Z23 from Flottweg.

[0264] Separation conditions: [0265] Flow rate: up to 500 Kg/h; [0266] Bowl speed: 4806 rpm (3000 G); [0267] Minimum Y: 5% (1.4 rpm).

[0268] Three fractions are obtained at the end of this separation phase: a fat fraction, a solid fraction and an aqueous fraction.

[0269] These fractions have the characteristics indicated in Table 2 below:

TABLE-US-00002 TABLE 2 Characteristics of the fat fraction, the solid fraction and the aqueous fraction. Dry Matter Proteins Oil Ash Carbohydrates (%) (%)* (%)* (%)* (%)* Solid 56 74.1 12.9 4 10 fraction Aqueous 10 57 4 9 23 Fraction Fat >99.5 <0.5 >99.5 <0.25 <0.25 fraction *Average results calculated over several samples of each of the fractions, expressed with respect to the % of dry matter

Determining the Size of the Soluble Proteins of the Solid Fraction and of the Aqueous Fraction

[0270] Preparation of the solid sample (solid fraction): 30 mg of the sample is solubilized in 1 L of mobile phase and filtered using the Chromafil Xtra PES-45/25 filter.

[0271] Preparation of the liquid sample (aqueous fraction): 400 μL is solubilized in 1600 μL of the mobile phase and filtered using the Chromafil Xtra PES-45/25 filter, just before injection. 1.5 mL of the sample thus prepared is centrifuged for 15 min at 12000 rpm (10625 g).

[0272] The conditions for implementing the chromatography (HPLC Nexera XR from Shimadzu) are as follows: the column used is a Superdex Peptide GL 10/300 (GE Healthcare), detection is carried out by a DAD detector at 215 nm, the speed of the mobile phase is 0.3 mL/min and it is composed of ACN (acetonitrile)/H.sub.2O/TFA (trifluoroacetic acid) (30/70/0.1), analysis is carried out at 25° C.

[0273] The size distribution of the soluble proteins of the solid fraction is shown in Table 3 below:

TABLE-US-00003 TABLE 3 The size distribution of the soluble proteins in the solid fraction 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

[0274] The size distribution of the soluble proteins of the aqueous fraction is shown in Table 4 below:

TABLE-US-00004 TABLE 4 The size distribution of the soluble proteins in the aqueous fraction 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

Determining the Quantity of Trehalose in the Solid Fraction and the Aqueous Fraction

[0275] The quantity of trehalose in these fractions was measured in the following manner:

[0276] The trehalose is analyzed by GC-MS.

[0277] Temperature programme: 150° C., followed by an increase of 10° C./min up to 260° C., after 5 minutes at this temperature, an increase of 25° C./min up to 310° C. and maintaining this temperature for 2 minutes. Temperature of the injector: 280° C., of the interface: 250° C., the split ratio is 10, the injection volume is 1 μL.

[0278] Preparation of the sample for analysis is carried out in the following manner: a precise quantity of the sample (between 10 and 300 mg) is weighed in a Falcon tube, 9.75 mL of methanol is added thereto as well as 250 μL of an internal standard solution (myo-inositol, 25 μg/mL) in DMSO. The mixture is stirred at 80° C. for 10 minutes, 100 μL of BSTFA is then added and the reaction mixture is stirred for 30 additional minutes at ambient temperature, 1 mL of acetonitrile is then added and the sample thus prepared is injected on a GC-MS device.

[0279] The quantity measured in the solid fraction is 3.82 mg of trehalose per g of dry matter.

[0280] The quantity measured in the aqueous fraction is 33.2 mg of trehalose per g of dry matter.

[0281] In addition, the aqueous fraction comprises less than 1% by weight insoluble sediments with respect to the total weight of the aqueous fraction.

Step 5: Concentrating the Aqueous Fraction

[0282] The aqueous fraction obtained in step 4 is then concentrated by evaporation, using a falling film evaporator.

[0283] The concentrated aqueous fraction obtained has a concentration of dry matter of approximately 65%.

Step 6 (optional): Mixing the Concentrated Aqueous Fraction and/or the Cuticles with the Solid Fraction

[0284] Step 6 was not implemented in this example.

Step 7: Drying the Solid Fraction

[0285] The solid fraction obtained in step 4 is dried using a disc dryer from Haarslev for 5 h in order to obtain a dry solid fraction or a dry mixture.

[0286] From a microbiological perspective, the solid fraction comprises less than 10 UFC/g of enterobacteria.

Step 8: Grinding

[0287] The dry solid fraction is finally ground using a continuous hammer mill (6 reversible moving parts—thickness 8 mm). The grinder is fed by a hopper with a flow rate control flap (180 kg/h). The perforated grill used to control the output granulometry is 0.8 mm. The speed of rotation of the motor is 3000 rpm (electric motorization, absorbed power 4 kW (5.5 HP)).

[0288] The characteristics of an insect powder obtained are given in Table 5 below.

TABLE-US-00005 TABLE 5 Characteristics of an insect powder obtained in Example 1. Proteins Chitin Ash Lipids Carbohydrates Trehalose 75.1% 1.3% 4% 12.5% 10% 0.38% *The percentages indicated are percentages by weight with respect to the total dry weight of the insect powder.

EXAMPLE 2

Process for Treating Insects According to the Invention

[0289] Steps 1 to 5 were implemented as described in Example 1.

Step 6 (optional): Mixing the Concentrated Aqueous Fraction and the Cuticles with the Solid Fraction

[0290] All (100%) of the concentrated aqueous fraction obtained in step 5 as well as 0.05% by weight cuticles recovered in step 2 were mixed with all of the solid fraction obtained in step 4 in order to obtain a mixture.

[0291] A conical screw mixer from Vrieco-Nauta® was used.

Step 7: Drying the Mixture

[0292] The mixture obtained in step 6 is dried using a disc dryer from Haarslev for 5 h in order to obtain a dry mixture.

[0293] From a microbiological perspective, the dry mixture comprises less than 10 UFC/g of enterobacteria.

Step 8: Grinding

[0294] The dry mixture is finally ground using a continuous hammer mill (6 reversible moving parts—thickness 8 mm). The grinder is fed by a hopper with a flow rate control flap (180 kg/h). The perforated grill used to control the output granulometry is 0.8 mm. The speed of rotation of the motor is 3000 rpm (electric motorization, absorbed power 4 kW (5.5 HP)).

[0295] The characteristics of an insect powder obtained are given in Table 6 below.

TABLE-US-00006 TABLE 6 Characteristics of the insect powder obtained in Example 2. Proteins Chitin Ash Lipids Carbohydrates Trehalose 66% 1% 6% 11% 13% 1.1% *The percentages indicated are percentages by weight with respect to the total dry weight of the insect powder.

EXAMPLE 3

Process According to the Invention and Comparative Processes

I. Preparation of the Samples

[0296] The process according to the invention for transforming the pulp of Tenebrio molitor larvae into oil (fat fraction or “TMO” for Tenebrio Molitor oil), an aqueous phase (aqueous fraction or “SW” for stickwater) and solid proteins (solid fraction or “SPC” for solid protein cake) and a comparative process were reproduced.

[0297] The object is to compare the quality of the products obtained by the 2 processes.

1. Process According to the Invention

[0298] The larvae are first killed by blanching (steaming) then the cuticles of the larvae are separated from the soft part (“decuticled”) by means of a belt separator from Baader.

[0299] 8 kg of the soft part resulting from the separation step is then sent for maturation in a pilot reactor with a capacity of 10 litres, said reactor being pre-heated to 50° C., under mechanical stirring at 350 rpm in order to ensure homogenization within the soft part. After a progressive increase in temperature of the soft part, the temperature is directly regulated at 90° C. in the mass thereof. After an hour of heating at 90° C., the reactor is emptied. The heated soft part is then separated. As the use of a tricanter is not possible at the laboratory level, the soft part is centrifuged at 10000 g for 15 minutes in order to separate the different phases obtained (see FIG. 2). Each phase (TMO, SW and SPC) is collected manually and stored at -20° C. awaiting physico-chemical analyses.

2. Comparative Process

[0300] 8 kg of the soft part resulting from the separation step is used. This soft part originated from the same batch of soft part as that used for the process according to the invention.

[0301] The comparative process differs from that according to the invention by two steps: [0302] at the end of the separation, an additional step of coagulating the soft part is carried out starting from 4 kg of soft part, in a pilot reactor, under stirring (350 rpm) with a reactor wall temperature fixed at 100° C. for 20 minutes; then [0303] the soft part is diluted by adding water and heated. Two dilutions of the soft part were carried out for these assays, 1:0.5 (w/w, weight/weight) and 1:0.75 (w/w). In concrete terms, a volume of water at 50° C. (2 litres or 3 litres as a function of the dilution) is added to the pilot reactor. The temperature in the pulp mass is regulated at 90° C. for one hour, 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. awaiting physico-chemical analyses.

II. Analyses of the Samples

Determining the Dry Matter of the Samples

[0304] The dry matter of the TMO, SW and SPC is determined by drying to constant mass at 105° C. according to standard ISO 6496. The weight difference of the product before and after drying serves as a measure of the dry matter content. These contents are expressed as a percentage by weight. The moisture content is obtained by subtracting the dry matter from the value 100.

Determining the Peroxide Value in TMO

[0305] The peroxide value is determined according to French standard NF EN ISO 3960 (June 2010) and expressed in meq of active oxygen/kg oil.

Sediments Content of the TMO and the SW

[0306] The filter used is a stainless-steel sieve with pores of 50 μm, calibrated beforehand. Quantification of the sediments is carried out after passing 300 mL TMO or 750 mL SW (750 mL) by weighing of the residues into the sieve.

[0307] In the case of the SW, the dry matter of the sediments is then determined as described above.

Evaluation of the Emulsion in the SW

[0308] Evaluation of the emulsion in the SW is carried out after centrifuging 50 mL collected SW. Collection of the emulsion (supernatant) is carried out after having placed the tubes at −20° C. in order to facilitate separation. The emulsion is then weighed and the result is expressed as the percentage of emulsion in the stickwater.

Determining the Fat in the SW

[0309] Determination of the fat or lipids in the SW samples is carried out by extraction with petroleum ether after hydrolysis according to EC Regulation 152/2009. The quantity of lipids is relative to the dry matter of the sample considered (SW or SPC).

Determining the Pepsin Digestibility of the SW

[0310] The pepsin digestibility is determined on the SW according to Directive 72/199/EC, without defatting.

Assaying Trehalose in the SW and the SPC

[0311] Trehalose is determined in the SW and the SPC after their lyophilization. 40 mg dry sample is extracted using 2 mL DMSO for 1 hour, under stirring at 80° C. 250 μL of the extract is then mixed with 50 μL myo-inositol, used as internal standard (1 g/L in DMSO). After homogenization, 100 μL of this mixture is derivatized with 100 μL BSTFA-TMCS (99:1) directly in the GC-MS vial for 30 minutes at 60° C. Before injection, 600 μL acetonitrile is added to the GC-MS vial. The results are expressed in mg trehalose/g dry using a trehalose standard range carried out under the same conditions (FIG. 3).

[0312] The derivatized extracts and the different points of the standard range are analyzed on a GC-MS-QP2010 from Shimadzu. The column used is an SH-Rxi 5 ms column (Shimadzu), with a length of 30 m, a diameter of 0.25 mm and a thickness of 0.25 μm. The temperature programme of the GC-MS is as follows: 100° C., followed by an increase of 10° C./min up to 300° C., maintained for 2 min.

[0313] 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 μL. Detection is carried out in SIM (selected ion monitoring) mode with specific m/z values of 305 for myo-inositol and 361 for trehalose.

Measuring the Colour of the Lyophilized SW

[0314] The colour was compared to a colour chart (RAL Classic K7 colour chart) and characterized by the colour code of this colour chart.

Determining the Soluble Fraction of the SPC

[0315] The experiments were carried out starting from lyophilized SPCs. 1 g sample is weighed (.sub.i) in a 50 mL tube calibrated beforehand. 30 mL water at ambient temperature is added and the tube is shaken (vortex) for several minutes. After centrifuging, the supernatant liquid is removed and a second washing is carried out with 30 mL water under the same conditions as the first. After the supernatant has been removed, the washed SPC pellet is placed in the oven at 60° C. for 48 hours then weighed. A control (unwashed SPC) is also placed in the oven in order to determine the percentage of actual dry matter and correct the initial weight of samples before washing (% DM).

[0316] The percentage of soluble is determined as:

[00001]$\frac{\left(\mathrm{mi}\times \%\mathrm{DM}\right)-\mathrm{dry},\mathrm{washed}\mathrm{mSPC}}{\mathrm{mi}\times \%\mathrm{DM}}$

Determining the Size of the Soluble Proteins of the SPC

[0317] The size of the soluble proteins of the SPCs is determined by steric exclusion chromatography.

[0318] 40 mg lyophilized sample is solubilized in the mobile phase composed of acetonitrile/H.sub.2O/TFA (trifluoroacetic acid) (30/70/0.1) in order to reach a concentration of 30 mg/mL and filtered to 45 μm after centrifuging using the Chromafil Xtra PES-45/25 filter. Simultaneously, the solubility of the dry SW and dry SPC in the mobile phase is determined after drying the centrifugation residues in the oven.

[0319] The conditions for implementing the chromatography carried out on a Nexera XR HPLC chain from Shimadzu are as follows: the column used is a Superdex Peptide GL 10/300 (GE Healthcare), 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 an acetonitrile/H.sub.2O/TFA (trifluoroacetic acid) mixture (30/70/0.1), analysis is carried out at 25° C.

[0320] In order to determine the molecular weight distribution, four “standard” proteins of known molecular weight were first injected in order to define retention time intervals corresponding to different molecular weights. In order to analyze the molecular distribution of the samples, the total area of the chromatogram is first integrated at 215 nm then separated into fractions corresponding to the five molecular weight categories. The results are expressed as a percentage of soluble proteins per molecular size category.

[0321] Determination of the soluble portion in the mobile phase is obtained in an analogous manner to that in water, but at 25% (analysis temperature).

III. Results

1. Fat Fraction

[0322] The results for the fat fraction are shown in FIGS. 4, 5 and 6.

[0323] With respect to the moisture content and the sediments content, FIGS. 4 and 5 demonstrate that the separation of the fat fraction is notably improved in the process according to the invention. Indeed, it is noted from these figures that there is a higher moisture content and sediments content in the fat fraction according to the comparative process. This result is unexpected as it is well known to a person skilled in the art that the augmentation of a phase and/or heating usually makes it possible to improve the separation of the phases in a complex medium.

[0324] Moreover, in FIG. 6, it is noted that the peroxide value of the fat phase obtained by the process according to the invention is lower than that of the fat phase obtained by the comparative process. The fat phase obtained by the process according to the invention thus has an improved preservation capacity. This is particularly advantageous since it makes it possible to avoid or to reduce the addition of a preservative such as antioxidants.

2. Aqueous Fraction

[0325] The results for the fat fraction are shown in FIGS. 7 to 13.

[0326] In FIG. 7, it is noted that there is a lower moisture content for the aqueous fraction obtained by the process according to the invention. Due to the dilution, the dry matter content is lower in the comparative process, which consequently requires larger equipment in order to recover the portion (dry matter) which is of interest and has a more intense energy consumption and water consumption in particular.

[0327] With respect to the sediments content, the emulsion content and the lipid content, FIGS. 8 to 10 demonstrate that the separation of the aqueous fraction is notably improved in the process according to the invention. Indeed, it is noted from these figures that there is a higher content of sediments, emulsion and lipids in the fat fraction according to the comparative process. This result is unexpected as it is well known to a person skilled in the art that the augmentation of a phase and/or heating usually makes it possible to improve the separation of the phases in a complex medium.

[0328] It is also noted that: [0329] in FIG. 11, the pepsin digestibility of the proteins of the aqueous fraction obtained by the process according to the invention is better than that obtained by the comparative process; and [0330] in FIG. 12, the trehalose content of the aqueous fraction obtained by the process according to the invention is better than that obtained by the comparative process.

[0331] The presence of trehalose is of interest because trehalose has the capacity to stabilize the proteins and is, because of this, considered to be a natural biological preservative.

[0332] Finally, FIG. 13 proposes 3 photographs of the aqueous fraction obtained either by the process according to the invention, or by the comparative process, and lyophilized. The aqueous fraction obtained by the process according to the invention has a notably lighter colour. From these figures, it thus emerges that a different product is obtained by the process according to the invention. This difference in colour can potentially be explained by the Maillard reaction that can take place during the coagulation and heating steps in aqueous medium which are carried out in the comparative process. During the Maillard reaction, the proteins of small size present in the medium are more susceptible to reacting, thus reducing the content of proteins of small size of the medium. This can in particular result in a reduction of the digestibility of the aqueous fraction.

3. Solid Fraction

[0333] The results for the solid fraction are shown in FIGS. 14 to 17.

[0334] In FIG. 14, it can be noted that the trehalose content of the solid fraction obtained by the process according to the invention is better than that obtained by the comparative process.

[0335] In FIG. 15, it can be noted that the content of soluble portion of the solid fraction obtained by the process according to the invention is better than that obtained by the comparative process. It is of interest to have a significant content of soluble portion because the soluble portion facilitates the formulation of the feedstuffs and confers an improved bioavailability, in particular by releasing the proteins of smaller size.

[0336] In FIGS. 16 and 17, it is demonstrated that the content of small proteins, i.e. proteins smaller than 550 Da, is higher in the solid fraction obtained by the process according to the invention than in that obtained by the comparative process.

[0337] It can thus be noted that the proteins of small size are better preserved by the process according to the invention. This translates into a higher solubility in water or in the mobile phase and into a higher proportion of proteins of small size in this solid fraction, the comparative process seemingly having contributed to the destruction of these products during the coagulation and heating phases.

4. Energy Consumption

[0338] Finally, energy consumption calculations were carried out in order to compare the process according to the invention with the two comparative processes.

[0339] The comparative process at a dilution of 1:0.5 incurs a cost 19.8 times higher than that of the process according to the invention and the comparative process at a dilution of 1:0.75 incurs a cost 20.2 times higher than that of the process according to the invention.