GEL COMPRISING A LIQUID COPRODUCT FROM AGRO-INDUSTRY AND USE THEREOF FOR REARING INSECTS

Abstract

The present invention relates to a gel used as a source of water and/or nutrients for rearing insects. The gel comprises 90 to 99.6% by weight of an aqueous substrate comprising at least 25% by weight, of the total weight of the aqueous substrate, of a liquid coproduct from agro-industry, 0.3 to 2% by weight of a gelling agent, and 0.1 to 5% by weight of a preservative, the percentages by weight of aqueous substrate, gelling agent and preservative being expressed over the total weight of the gel.

Claims

1. Gel comprising: 90 to 99.6% by weight of an aqueous substrate comprising at least 25% by weight with respect to the total weight of aqueous substrate, of a liquid coproduct from agro-industry, from 0.3 to 2% by weight of a gelling agent, and from 0.1 to 5% by weight of a preservative, the percentages by weight of aqueous substrate, gelling agent and preservative being expressed with respect to the total weight of the gel, said gel having a water content greater than 50% by weight with respect to the total weight of gel.

2. Gel according to claim 1, in which the agro-industry is selected from the industries of starch manufacture, potato starch manufacture, malting, bioethanol production, sugar, fermentation, brewing, distillation and the dairy industry.

3. Gel according to claim 1, in which the aqueous substrate comprises at least 50% by weight of a liquid coproduct from agro-industry with respect to the total weight of aqueous substrate.

4. Gel according to claim 1, in which the aqueous substrate comprises water.

5. Gel according to claim 4, in which the aqueous substrate consists of water and a liquid coproduct from agro-industry.

6. Gel according to claim 1, in which the aqueous substrate consists of a liquid coproduct from agro-industry.

7. Gel according to claim 1, in which the liquid coproduct from agro-industry is selected from the list constituted by solubles from cereals, solubles from maize, solubles from wheat, solubles from peas, solubles from cassava, solubles from sugar beet, solubles from sugar cane, distillers' solubles from cereals, distillers' solubles from wheat, distillers' solubles from maize, distillers' solubles from peas, distillers' solubles from cassava, vinasses, molasses, yeast creams, whey and concentrated derivatives thereof, in particular permeate, or mixtures thereof.

8. Gel according to claim 1, in which the liquid coproduct from agro-industry is a distillers' soluble or a mixture of a distillers' soluble and another liquid coproduct.

9. Gel according to claim 1, in which the gelling agent is a mixture of xanthan and carob gums, or a mixture of xanthan and guar gums.

10. Gel according to claim 1, comprising yeasts.

11. Gel according to claim 1, further comprising from 0.001 to 0.5% by weight of vitamins with respect to the total weight of the gel.

12. Gel according to claim 1, having a gel strength of at least 30 g/cm.sup.2.

13. Nutrition regime for insects comprising a gel and a feed: the gel being according to claim 1, and the feed being an insoluble substrate having a moisture content less than or equal to 55% by weight with respect to the total weight of the insoluble substrate.

14. Method for preparing a gel according to claim 1, comprising: a step of forming a liquid compound by mixing: i. from 90 to 99.6% by weight of an aqueous substrate comprising at least 25% by weight with respect to the total weight of aqueous substrate, of a liquid coproduct from agro-industry, the aqueous substrate being brought to a temperature allowing dissolution of a gelling agent; ii. from 0.3 to 2% by weight of a gelling agent, and iii. from 0.1 to 5% by weight of a preservative, the percentages by weight of gelling agent and of preservative being expressed with respect to the total weight of the liquid compound, a step of cooling the liquid compound so as to bring it below a second temperature, at which it gels.

15. Use of a gel according to claim 1, as a source of water and/or nutrients for rearing insects.

16. Use of a liquid coproduct from agro-industry in gel form as a source of water and/or nutrients for rearing insects.

Description

[0172] The invention will be better understood on reading the following examples given by way of illustration, with reference to the figures:

[0173] FIG. 1a is a diagram illustrating the growth and mortality of larvae of Tenebrio molitor with rearing on gels comprising various liquid coproducts from agro-industry (two solubles from wheat, a distillers' soluble from cereals and a vinasse);

[0174] FIG. 1b corresponds to the growth curve of Tenebrio molitor with rearing on gels comprising the liquid coproducts from agro-industry mentioned in FIG. 1a;

[0175] FIG. 1c is a diagram illustrating the feed conversion ratio FCR, also called consumption index, calculated for Tenebrio molitor depending on the liquid coproduct from agro-industry, in the form of gel, that was incorporated into its nutrition regime;

[0176] FIG. 2 comprises a FIG. 2a, which is a table showing comparative nutrition regimes comprising liquid coproducts from wheat and maize from a starch mill, dried or lyophilized, as well as a FIG. 2b, which comprises two diagrams illustrating the results obtained in terms of growth and FCR of the feed, obtained for different comparative nutrition regimes stated in FIG. 2a;

[0177] FIG. 3 comprises a FIG. 3a, which is a table showing comparative nutrition regimes comprising liquid coproducts from starch manufacture from wheat, dried or lyophilized, as well as a FIG. 3b, which comprises two diagrams illustrating the results obtained in terms of growth and FCR of the feed, obtained for different comparative nutrition regimes stated in FIG. 3a;

[0178] FIG. 4 comprises a FIG. 4a, which is a table showing comparative nutrition regimes comprising liquid coproducts from wheat and maize from a starch mill, in wet form or in the form of gel, as well as a FIG. 4b, which comprises two diagrams illustrating the results obtained in terms of growth and FCR of the feed, obtained for different comparative nutrition regimes stated in FIG. 4a;

[0179] FIG. 5 comprises a FIG. 5a, which is a table showing comparative nutrition regimes comprising liquid coproducts from wheat and maize from a starch mill, in wet form or in the form of gel, and a FIG. 5b, which comprises two diagrams illustrating the results obtained in terms of growth and FCR of the feed, obtained for different comparative nutrition regimes stated in FIG. 5a; and

[0180] FIG. 6 shows the evaluation of the mechanical properties of the gels enriched with solubles from wheat with incorporation of gelling agent (Xanthan Carob mixture) of 0.30%, 0.50% and 0.70% of example IV (measurement of the gel strength as a function of the distance traveled by a cylindrical probe used for applying pressure to the surface of the gel) carried out using a TA-XT Plus texturometer (Stable Micro Systems, TA.XT Plus, Surrey, France) and its Exponent analysis software.

EXAMPLE I: EXAMPLES OF GELS ACCORDING TO THE INVENTION

[0181] A. The Products Used in the Gels According to the Invention

[0182] a) Solubles

[0183] Solubles from Maize [0184] SOLULYS 048E, marketed by ROQUETTE. SOLULYS corresponds to a concentrated solution of solubles from maize obtained in the first step of fractionation of the grain, in a wet process for starch manufacture. This concentrated solution comprises 48% by weight of dry matter with respect to the total weight of solution and 44% by weight proteins and 24% by weight lactic acid, these last two percentages by weight being expressed with respect to the total weight of dry matter of the solution. [0185] AMYSTEEP424, marketed by TEREOS. This composition of solubles from maize comprises 42.5% by weight dry matter with respect to the total weight of the composition and 44% by weight proteins with respect to the total weight of dry matter of the composition.

[0186] Solubles from Wheat [0187] CORAMI, marketed by ROQUETTE. It corresponds to a soluble from starch extraction obtained following the steps of steeping and refining, in a starch mill process. This composition of wheat soluble comprises 29% by weight dry matter with respect to the total weight of the composition.

[0188] b) Distillers' Solubles

[0189] Distillers' Solubles from Wheat [0190] ALCOMIX, marketed by the company TEREOS. This composition of wheat soluble comprises about 20% by weight dry matter with respect to the total weight of the composition and about 28% by weight proteins with respect to the total weight of dry matter of the composition. [0191] PROTIWANZE, marketed by the company CROPENERGIES. This distillers' soluble from wheat comprises 27% by weight dry matter with respect to the total weight of distillers' soluble and 27% by weight proteins with respect to the total weight of dry matter of distillers' soluble. [0192] CORAMI BE, marketed by ROQUETTE. This distillers' soluble from wheat comprises 32% by weight dry matter with respect to the total weight of distillers' soluble and 32% by weight proteins with respect to the total weight of dry matter of distillers' soluble.

[0193] Distillers' Solubles from Cereals [0194] distillers' soluble originating from wheat, maize and barley, supplied by the company CROPENERGIES.

[0195] c) Yeast Creams [0196] yeast cream from wheat supplied by TEREOS.

[0197] d) Vinasses [0198] VINASSE 60 marketed by LESAFFRE. This vinasse comprises 60% by weight of dry matter with respect to the total weight of vinasse and 60% by weight of proteins with respect to the total weight dry matter of vinasse. [0199] VIPROTAL marketed by LESAFFRE. This vinasse comprises 60% by weight dry matter with respect to the total weight of vinasse and 44% by weight proteins with respect to the total weight dry matter of vinasse. [0200] PRL 364 marketed by AJINOMOTO. This vinasse comprises 70% by weight dry matter with respect to the total weight of vinasse and 70% by weight proteins with respect to the total weight dry matter of vinasse. [0201] SIRONAL marketed by AJINOMOTO. This vinasse comprises 66% by weight dry matter with respect to the total weight of vinasse and 52.8% by weight proteins with respect to the total weight dry matter of vinasse.

[0202] e) Molasses [0203] SUGARCANE MOLASSES marketed by PRIMEAL. This molasses comprises 75% by weight dry matter with respect to the total weight of molasses and 5% by weight proteins with respect to the total weight dry matter of molasses. [0204] BEET MOLASSES marketed by CRISTALUNION. This molasses comprises 75% by weight dry matter with respect to the total weight of molasses and 14% by weight proteins with respect to the total weight dry matter of molasses.

[0205] f) Probiotics [0206] Yeasts LB 2245 marketed by LALLEMAND having the characteristics given in Table 1 below:

TABLE-US-00001 TABLE 1 Composition of Yeasts LB 2245 Yeasts LB 2245 (%) Vitamin A (IU)< 0.0003 Water 6 Protids 45.00 Total lipids 15.00 SAT fatty acids 10.00 Total carbohydrates 42.10 Soluble sugars 24.00 Fibres 16.60 Sodium 0.047 Calcium 0.212 Iron 0.005 Vitamin B1: Thiamine 0.004 Vitamin B2: Riboflavin 0.003 Vitamin B3: Nicotinic acid 0.048 Vitamin B5: Pantothenic acid 0.003 Vitamin B6: Pyridoxine 0.003 Vitamin B8: Biotin 0.0001 Vitamin B9: Folic acid 0.0002 Vitamin B12: Cobalamin 0.00001 Remarks Inactive yeasts, containing gluten from barley and wheat

[0207] g) Vitamin Premixes [0208] Vitamin premix PX SHRIMP V 0.5 marketed by MIXSCIENCE having the characteristics given in Table 2 below:

TABLE-US-00002 TABLE 2 Composition of the premix Premix (%) Iron 0.20 Iodine 0.01 Cobalt 0.00238 Copper 0.60 Manganese 0.40 Zinc 0.3 Selenium - Sodium selenite 0.008 BHT 0.40 Vitamin A (IU)< 0.60 Vitamin B1: Thiamine 1.00 Vitamin B2: Riboflavin 1.20 Vitamin B5: Pantothenic acid 3.00 Vitamin B6: Pyridoxine 1.00 Vitamin B8: Biotin 0.01 Vitamin B9: Folic acid 0.16 Vitamin B12: Cobalamin 0.0001 PP - Niacin 3.00 D3 0.0015 E 2.941176 K3 0.20

[0209] B. Formulation of Gels According to the Invention

[0210] a) Gel Comprising a Probiotic and an Aqueous Substrate Constituted by Solubles from Maize

TABLE-US-00003 wt % with respect to the total weight of gel Solubles from maize 94.09 Probiotics 4.81 Gelling agent ( 0.8 Xanthan gum + Carob gum) Potassium sorbate 0.3

[0211] b) Gel Comprising a Vitamin Premix and an Aqueous Substrate Constituted by Solubles from Wheat

TABLE-US-00004 wt % with respect to the total weight of gel Solubles from wheat 94.09 Vitamin premix 4.81 Gelling agent ( 0.8 Xanthan gum + Carob gum) Potassium sorbate 0.3

[0212] c) Gel Comprising a Vitamin Premix and an Aqueous Substrate Constituted by Solubles from Maize

TABLE-US-00005 wt % with respect to the total weight of gel Solubles from maize 95.93 Premix 2.97 Gelling agent ( 0.8 Xanthan gum + Carob gum) Sodium propionate 0.3

[0213] d) Gel Comprising 75% of a Distillers' Soluble from Wheat and 25% of Water in the Aqueous Substrate

TABLE-US-00006 wt % with respect to the total weight of gel Distillers' soluble 74.17 from wheat Water 24.73 Gelling agent ( 0.8 Xanthan gum + Carob gum) Potassium sorbate 0.3
e) Gel Comprising an Aqueous Substrate Constituted by a Soluble from Wheat

TABLE-US-00007 wt % with respect to the total weight of gel Soluble from wheat 98.9 Gelling agent ( 0.8 Xanthan gum + Carob gum) Potassium sorbate 0.3

[0214] f) Gel Comprising an Aqueous Substrate Constituted by a Mixture of Soluble from Wheat and Soluble from Maize

TABLE-US-00008 wt % with respect to the total weight of gel solubles from maize 95.9 solubles from wheat 3.0 Gelling agent ( 0.8 Xanthan gum + Carob gum) Potassium sorbate 0.3

[0215] g) Gel Comprising an Aqueous Substrate Constituted by a Mixture of Soluble from Wheat at 75%, Gelled with Agar-Agar

TABLE-US-00009 wt % with respect to the total weight of gel soluble from wheat 75.0 Water 24.2 Agar-agar 0.5 Potassium sorbate 0.3

[0216] C. Preparation of a Gel

[0217] The above gels may be prepared as follows.

[0218] The coproduct(s) from agro-industry(ies) and optionally water is(are) heated in a stirred vat to a temperature greater than 80 C., then mixed with the other constituents of the mixture: the optional probiotics and premixes, with at least one gelling agent and with at least one preservative in the proportions given. The mixture thus obtained is then brought gradually back to ambient temperature so that the gel forms.

EXAMPLE II: EFFECTS OF DIFFERENT GELS ACCORDING TO THE INVENTION ON THE DEVELOPMENT OF THE LARVAE OF TENEBRIO MOLITOR

[0219] Four coproducts from agro-industry were tested: two solubles from wheat (SB1 and SB2), a vinasse (VF) and a cereal soluble obtained from wheat, maize and barley (SC)

[0220] A gel was formed according to Example I, constituted by 99% by weight with respect to the total weight of gel, of an aqueous substrate comprising 25% by weight, with respect to the weight of aqueous substrate, of each of the aforementioned coproducts from agro-industry and 75% by weight, with respect to the weight of aqueous substrate of water, 0.7% of Flanogen XL12 (Cargill), a 50/50 mixture of xanthan gum and carob gum, and 0.3% of potassium L-sorbate.

[0221] A control gel was also formed constituted by water, 0.7% by weight of Flanogen XL12 (Cargill) and 0.3% by weight of potassium L-sorbate, the percentages by weight being with respect to the total weight of gel.

[0222] The larvae of Tenebrio molitor used for each series of experiments come from the same population originating from the laboratory rearing station of Ynsect at Evry, at two different times.

[0223] The experiments began with 10 grams of larvae after fasting for 48 h, with individual weight of about 20 mg.

[0224] They were reared at an optimum density of 0.63 g/cm.sup.2 in transparent plastic jars with a square base (dimensions: 447.5 cm).

[0225] At each feed, the weight of insects is adjusted to 10 grams by random selection of a sample of individuals in order to return to the optimum density.

[0226] The experiments lasted 14 days and were carried out in the dark, in a climate chamber in order to control the temperature at 24 C. and the relative humidity at 60%. The larvae of Tenebrio molitor were fed ad libitum twice a week with a basic medium and the gels obtained as above.

[0227] At the end of the experiment the medium was weighed in order to evaluate the growth and mortality of the larvae reared in this way.

[0228] For calculating the daily growth rate it is necessary to determine the theoretical total growth, correcting for the effect of the successive dilutions. For this, the theoretical larval biomass (Mcumul) is evaluated again each time data are obtained (t), from the results of weighing larval mass (ML) according to the following formula:

[00001]$\mathrm{Mcumul}\left(t\right)=\mathrm{Mcumul}\left(t-1\right)+\mathrm{Mcumul}\left(t-1\right)\frac{\mathrm{ML}\left(t\right)-\mathrm{ML}\left(t-1\right)}{\mathrm{ML}\left(t-1\right)}$

The daily growth rate (GR) is calculated between the initial larval mass (ML(t0)=10 g) and the theoretical larval mass at the end of the experiment (tf) according to the following formula:

[00002]$\mathrm{GR}=\frac{\mathrm{Mcumul}\left(\mathrm{tf}\right)-\mathrm{ML}\left(\mathrm{t0}\right)}{\mathrm{ML}\left(\mathrm{t0}\right).Math.t}$

[0229] To estimate the mortality, the mean value of the daily apparent mortality rates between each data acquisition was calculated. The daily mortality rates were determined by dividing the number of deaths counted by the number of days between two feeds.

[0230] The results obtained are presented in FIG. 1a.

[0231] It is noted that adding a gel comprising the coproducts to the rearing medium of the larvae makes it possible to increase the growth of the larvae compared to a medium comprising a gel constituted only by water. Furthermore, the addition of such a gel, advantageously makes it possible to reduce the mortality of the larvae compared to the value of the control (gel constituted by water).

[0232] In FIG. 1b, it is noted that the biomass of the rearing medium increases throughout the 14 days of culture (from 10 g to 35 g). The biomass gain in the experiments conducted in the presence of gel comprising a coproduct is greater than the biomass gain in the control experiment, conducted in the presence of a gel comprising only water (difference of about 8 g).

[0233] Moreover, the feed conversion ratio FCR was calculated (by the method indicated in Table 3 below) for all of the experiments that were conducted. The results are presented in FIG. 1c. It can be seen that the feed conversion ratio in the experiments conducted in the presence of a coproduct is less than or equivalent to that obtained for the control.

[0234] In conclusion, the use of coproduct in gel form as the source of nutrients and water is particularly advantageous for growing larvae of Tenebrio molitor and gives improved growth compared to a gel constituted by water.

EXAMPLE III: ADVANTAGES OF THE GELS ACCORDING TO THE INVENTION FOR THE DEVELOPMENT OF LARVAE OF TENEBRIO MOLITOR

[0235] Two series of experiments were undertaken based on nutrition regimes composed of coproducts from two starch mills, from wheat and maize for the first (factory A) and from wheat for the second (factory B).

[0236] The aims of each of these experiments were (1) to evaluate the effect of industrial drying on the nutritional quality of the coproducts and (2) to test the use of liquid coproducts in particular by incorporation in a gel that is simultaneously nutrient and a source of water, on performance in rearing Tenebrio molitor.

[0237] a) Biological Material and Rearing Conditions

[0238] The larvae of Tenebrio molitor used for each series of experiments were from the same colony originating from the laboratory rearing station of Ynsect at Evry and were taken at two different times.

[0239] The experiments began with 10 grams of larvae after fasting for 48 h, with individual weight of about 20 mg.

[0240] They were reared at an optimum density of 0.63 g/cm.sup.2 in transparent plastic jars with a square base (dimensions: 447.5 cm).

[0241] At each feed, the weight of insects is adjusted to 10 grams by random selection of a sample of individuals in order to return to the optimum density.

[0242] The experiments lasted 2 weeks and were carried out in the dark in a climate chamber in order to control the temperature at 25 C. and the relative humidity at 60%. The larvae of Tenebrio molitor were fed ad libitum twice a week with 11 g of feed and a quantity of gel adjusted according to the moisture content of the substrate (see preceding paragraph). In total, the substrate was renewed 4 times, the renewal events corresponding to the different data acquisitions.

[0243] b) Experimental Procedure and Data Acquisition

[0244] The data were collected at each feed. The individuals were separated from the feed by manual sieving using a suitable sieve mesh as a function of the size of the individuals. The dead individuals were removed and counted. The live individuals were also counted. The live larvae and the residual matter (unconsumed feed, remaining gel and faeces) were weighed and a small portion (about 2 grams) was placed at 105 C. for 24 h and then weighed to determine the dry matter.

[0245] The variables studied are the daily growth rate (GR, calculated as stated in Example II) and the feed conversion ratio (FCR).

[0246] For calculating the FCR it is necessary to know the weight of feed consumed. However, the latter can only be obtained with difficulty by sieving, if at all, therefore it is necessary to perform a calculation and an intermediate experiment starting from a method by indirect calculation (confirmed in-house in the laboratory) so that the apparent digestibility and its derived indicator, the rejection rate (RR), are constant throughout the experiment, in other words so that the weight of faeces (or weight of frass) produced is proportional to the weight of feed ingested. An experiment in which 10 grams of larvae of Tenebrio molitor consumed their feed completely was therefore carried out for all the treatments in order to obtain the RR. The formulae for the calculations are given in the following table (Table 3).

TABLE-US-00010 TABLE 3 Formulae for calculating the feed conversion ratio (FCR) Variables Unit Formulae FCR [00003]$F.Math..Math.C.Math..Math.R=\frac{\mathrm{Weight}.Math..Math.\mathrm{of}.Math..Math.\mathrm{feed}.Math..Math.\mathrm{consumed}}{\mathrm{Biomass}.Math..Math.\mathrm{gain}}$ RR % [00004]$R.Math..Math.R=\frac{\mathrm{Weight}.Math..Math.\mathrm{of}.Math..Math.\mathrm{frass}}{\mathrm{Weight}.Math..Math.\mathrm{of}.Math..Math.\mathrm{feed}.Math..Math.\mathrm{consumed}}$ Weight of feed consumed (Mc) g [00005]$\mathrm{Mc}\left(t\right)=\frac{\mathrm{Substrate}.Math..Math.\mathrm{weight}.Math..Math.\left(0\right)-\mathrm{Substrate}.Math..Math.\mathrm{weight}.Math..Math.\left(t\right)}{1-R.Math..Math.R}$

[0247] c) Evaluation of the Effect of Industrial Drying on the Nutritional Quality of the Coproducts

[0248] The treatments with a code ending with the letter S (A1S and A2S, B1S and B2S) correspond to nutrition regimes composed of a gel constituted only by water and a nutrient substrate, said substrate corresponding to liquid coproducts dried by two methods of drying: industrial drying and drying by lyophilization.

[0249] Preparation of the Feed and of the Gel

[0250] The nutrition regimes are formulated so as to respect the proportions of production of the coproducts given with respect to dry matter for each starch mill investigated.

[0251] The coproducts from starch manufacture included in the other nutrition regimes are: [0252] wheat bran (WB_A and WB_B), [0253] solubles from wheat originating from starch extraction (SB_A), [0254] solubles from wheat originating from starch extraction, mixed with the solubles and the yeasts from distillation (SB_B),

[0255] WB_0 corresponds to a wheat bran from milling.

[0256] The ingredients used at 100% in treatments A1S (CPT_A) and B1S (CPT_B) correspond to products sold by the starch mills (dried industrially on site) and are composed by the liquid coproducts dried by lyophilization used in the respective nutrition regimes A2S (WB_A and SB_A) and B2S (WB_B and SB_B), and for which the proportions were maintained.

[0257] For each series, a control treatment composed of a nutrition regime based on wheat bran from milling and a gel comprising an aqueous substrate constituted by water was included (A0 and B0).

[0258] Each treatment was repeated 3 times.

[0259] Starch Mill A

TABLE-US-00011 TABLE 4 Design of experiments on the coproducts from starch mill A, composition of the nutrition regimes Moisture Substrate (%)** content of Code State WB 0 CPT A WB A SB A substrate A0 DRY 100% 0.00 0.00 0.00 11% A1S DRY 0.00 100% 0.00 0.00 9% A2S DRY/LYO* 0.00 0.00 65% 35% 8% *The feed was lyophilized **The percentages are expressed with respect to dry matter

[0260] Starch Mill B

TABLE-US-00012 TABLE 5 Design of experiments on the coproducts from starch mill B, composition of the nutrition regimes Moisture Substrate (%)** content of Code State WB 0 CPT A WB B SB B substrate B0 DRY 100% 0.00 0.00 0.00 11% B1S DRY 0.00 100% 0.00 0.00 10% B2S DRY/LYO* 0.00 0.00 70% 30% 9% *The feed was lyophilized **The percentages are expressed with respect to dry matter

[0261] All the dry nutrition regimes were prepared individually before the start of the study and stored in a dry, stable environment. For the treatments dried by lyophilization, the wet mixture of the coproducts is first placed at 80 C. for 24 hours, then kept in the lyophilizer for 3 days.

[0262] All the treatments received 11 grams of food per feed, independently of their dry matter content.

[0263] Regarding the gel given to the larvae of Tenebrio molitor as the source of water, it corresponds to small pieces composed of 0.75% of Flanogen XL12 (Cargill, France), which is a mixture of xanthan and carob gums, 0.3% of potassium sorbate, and made up with water. For the dry substrates, with a water content less than or equal to 15%, 6 grams of water were supplied by the gel.

[0264] Results

[0265] The nutrition regimes are presented in FIGS. 2a and 3a; the results are given in FIGS. 2b and 3b for the products from factory A and factory B, respectively.

[0266] As can be seen from these results, rearing carried out on dry substrates (A1S) and (B1S) does not make it possible to obtain such good yields in terms of growth and FCR as rearing carried out on lyophilized liquid substrates, (A2S/FIG. 2) and (B2S/FIG. 3) respectively.

[0267] As a result, it can be seen that industrial drying affects the nutritional quality of the coproducts used. It is therefore preferable to use the latter in their liquid form.

[0268] d) Use of Liquid Coproducts in Particular Incorporated in a Gel on Performance in Rearing Tenebrio molitor

[0269] The treatments make it possible to compare the different uses of the liquid coproducts: mixed in a wet substrate (A3 and B3) or incorporated in the gel (A4, A5 and B4).

[0270] Preparation of the Feed and of the Gel

[0271] The nutrition regimes are composed so as to respect the proportions of production of the coproducts given with respect to dry matter for each starch industry investigated.

[0272] The coproducts from starch manufacture included in the nutrition regimes are: [0273] wheat bran (WB_A and WB_B), [0274] solubles from wheat originating from starch extraction (SB_A), [0275] solubles from wheat originating from starch extraction and mixed with the solubles and with the distillation yeasts (SB_B), [0276] solubles from maize originating from the steeping process (SM_A), [0277] maize germ cake (GM_A), and [0278] wet maize fibres (FM_A).

TABLE-US-00013 TABLE 6 Design of experiments on the coproducts from starch mill A, composition of the nutrition regimes Moisture Gel Substrate (%)** Gel (%)** content of Code enriched WBA SBA SM A GM A FM A SB A SM A substrate A3 No 39.0% 21.0% 12.0% 5.9% 22.1% 0.00 0.00 52% A4 Yes 39.0% 0.00 12.0% 5.9% 22.1% 21.0% 0.00 42% A5 Yes 39.0% 4.9% 12.0% 5.9% 22.1% 16.1% 9.2% 44% **The percentages are expressed with respect to dry matter

TABLE-US-00014 TABLE 7 Design of experiments on the coproducts from starch mill B, composition of the nutrition regimes Gel Moisture Gel Substrate (%)** (%)** content of Code enriched WB B SB B SB B substrate B3 No 70.0% 30.0% 0.00 56% B4 Yes 70.0% 30.0% 19.5% 49% **The percentages are expressed with respect to dry matter

TABLE-US-00015 TABLE 8 Composition of the gels (starch mill A) Weight Water Gel Gel (%) of gel content Code enriched SB A SM A WATER (g) of the gel A3 No 0% 0% 100% 3.5 g 100% A4 Yes 100% 0% 0% 5.8 g 70.7% A5 Yes 74.5% 25.5% 0% 6.1 g 66.1%

TABLE-US-00016 TABLE 9 Composition of the gels (starch mill B) Water Gel Weight content Gel (%) of gel of the Code enriched SB B WATER (g) gel B3 No 0.00 100% 3.2 g 100% B4 Yes 75.0% 25.0% 4.4 g 85.1%

[0279] All the dry nutrition regimes were prepared individually before the start of the study and were stored in a dry, stable environment.

[0280] All the wet nutrition regimes were prepared on the day of feeding to keep the moisture content of the substrate stable and avoid microbiological contamination. Powdered potassium sorbate was also added (0.3%) to the substrate and mixed well. All the treatments received 11 grams of food per feed, independently of their dry matter content.

[0281] Regarding the gel given to the larvae of Tenebrio molitor, it corresponds to small pieces composed of 0.75% of Flanogen XL12 (Cargill, France), which is a mixture of xanthan and carob gums, 0.3% of potassium sorbate and made up with water and/or a liquid coproduct, depending on the treatment. The quantity of gel provided in the diet was adjusted as a function of the moisture content of the substrate to avoid overfeeding the larvae of Tenebrio molitor with water. For the dry substrates with a water content less than or equal to 15%, 6 grams of water was supplied by the gel.

[0282] For the substrates with a water content greater than 15%, the quantity of water to be supplied by the gel was calculated according to the following formula:

[Weight of water in the gel in grams]=([Moisture content of the substrate as percentage]/15%)+7

[0283] As before, the nutrition regimes are composed so as to respect the proportions of production of the coproducts given with respect to dry matter for each starch mill investigated.

[0284] For each series, a control treatment composed of a nutrition regime based on wheat bran from milling and gel was included (A0 and B0). WB_0 corresponds to wheat bran from milling.

[0285] Each treatment was repeated 3 times.

[0286] Results

[0287] The nutrition regimes are presented in FIGS. 4a and 5a; the results are given in FIGS. 4b and 5b for the products originating from factory A and factory B.

[0288] Comparison of rearing conducted on a wet substrate comprising a coproduct (A3) and (B3), and on a substrate comprising the coproduct(s) in the form of gel (A4, A5) and (B4), clearly shows that the growth rate is better when the coproduct is supplied in the form of gel, as well as the FCR (the rate having to be as low as possible).

[0289] This may be explained by the fact that a wet medium increases the mortality of individuals. Thus, supplying the coproduct in the form of gel makes it possible to supply a coproduct in a liquid form the nutritional qualities of which are preserved, without causing an increased risk of mortality, which would be due to an excessive water content of the medium.

EXAMPLE IV

[0290] Evaluation of the Effect of the Percentage of Gelling Agent on the Physical Properties of the Enriched Gels and the Consequences on the Consumption of the Larvae;

[0291] Investigation of Different Gelling Agents on the Strength of the Enriched Gels for Three Levels of Incorporation;

[0292] Consequences on the Consumption of the Larvae.

[0293] a) Preparation of the Gels

[0294] The gels used in this study are presented in Table 10 below. The liquid coproduct (solubles from wheat originating from starch extraction, mixed with the solubles and with the distillation yeasts) is incorporated between 99% and 99.4% in the enriched gels, counting addition of potassium sorbate at 0.3% and according to inclusion of the gelling agent at 0.30%, 0.50% and 0.70% (by weight with respect to the total weight of the gel). The gelling agents used are: a mixture of xanthan and carob gums (Flanogen XL12, Cargill France), a mixture of xanthan and guar gums (Algaia, France) and agar-agar intended for the agri-food industry (Biocean, France). The enriched gels were produced at 80 C. for 15 minutes using an Amicook multifunction food processor (Amicook Family gourmet, France). They were poured quickly into cylindrical dishes with a volume of 137.4 cm.sup.3, and then placed at 4 C. for 24 hours for setting. All the gels have a standard volume of 78.5 cm.sup.3 (height: 4 cm; diameter: 5 cm).

TABLE-US-00017 TABLE 10 Preparation of the enriched gels Liquid coproduct Solubles from wheat Gelling agent Xanthan Carob Xanthan Guar Agar % incorporation 0.30% 0.30% 0.30% of gelling 0.50% 0.50% 0.50% agent 0.70% 0.70% 0.70%

[0295] b) Analysis of Gel Texture

[0296] The mechanical properties of the gels were evaluated using a TA-XT Plus texturometer (Stable Micro Systems, TA.XT Plus, Surrey, France) and its Exponent analysis software. This method makes it possible to measure the hardness, elasticity and mainly the strength of the different gels tested. A cylindrical spindle with a diameter of 6.45 mm was used for applying pressure to the surface of the gel until the maximum depression of 20 mm after contact was reached. The speed of penetration was fixed at 1.6 mm/s and the speed of withdrawal at 10 mm/s. The test was carried out with the gels enriched with solubles from wheat with a concentration of gelling agent (Xanthan Carob mixture) of 0.30%, 0.50% and 0.70%. In FIG. 6, the bottom curve relates to incorporation of 0.30% of gelling agent, the middle curve relates to incorporation of 0.50% of gelling agent and the top curve relates to incorporation of 0.70% of gelling agent.

[0297] The following texture parameters were determined from the graph in FIG. 6 representing the strength as a function of the distance traveled by the probe: [0298] the gel strength (g/cm.sup.2) corresponding to the force required for breaking and piercing the gel, [0299] the deformation (mm) corresponding to the distance traveled by the probe between initial contact and rupture of the gel, and [0300] the firmness, corresponding to the ratio of the gel strength to its deformation.

[0301] c) Study of the Rate of Consumption of the Gels by the Larvae of Tenebrio molitor

[0302] The larvae of Tenebrio molitor used for this experiment were from the same colony originating from the laboratory rearing station of Ynsect at Evry and were taken from the same batch at the same time. They were fasted for 48 h before the start and had a mean initial weight of 33 mg. A ratio of 0.5 g of gel to 2.5 g of larvae was placed in transparent plastic jars with a square base (dimensions: 447.5 cm). The enriched gels were cut out using a punch and placed at the centre of the jar to guarantee the same area of access to the gel by the larvae.

[0303] The experiment was carried out in the dark in a climate chamber in order to control the temperature at 26 C. and the relative humidity at 60%. Observations were carried out hourly until complete consumption of the gel. Once the gel had been consumed completely, the mortality and the individual weight of the larvae were found by counting and weighing.

[0304] d) Results

[0305] d1) Effect of the Concentration of Gelling Agent on the Strength of the Enriched Gel and on the Consumption of the Larvae

[0306] The results presented in Table 11 below show that the strength and the firmness of the gel increase with the concentration of gelling agent, ranging from a strength of 56.92 g/cm.sup.2 for 0.3% to 149.09 g/cm.sup.2 for 0.7%, i.e. a tripling of the strength for an increase of 0.4% in the concentration of gelling agent. The capacity for deformation of the gels increases slightly with the concentration of gelling agent.

TABLE-US-00018 TABLE 11 Results for strength, deformation, firmness and consumption of the gels enriched with solubles from wheat (gelling agent: Xanthan Carob). % incor- poration Consumption Weight of gelling Strength Deformation Firmness time gain agent (g/cm.sup.2) (mm) (slope) (h) (%) 0.30% 56.92 5.92 14.27 9.7 (+/0.7) 9.8% 0.50% 117.15 6.17 29.28 10.3 (+/0.3) 10.1% 0.70% 149.02 6.27 36.98 14.7 (+/1.2) 9.0%

[0307] The results show that the consumption time of the gels increases slightly with the concentration of gelling agent: 5 hours of additional consumption time for a gel at 0.7% of gelling agent relative to a gel at 0.3%. The mortality and the weight gain of the larvae are equivalent regardless of the concentration of gelling agent. Thus, the results show that a gel enriched with liquid coproducts is more easily consumed by the larvae of T. molitor when the gel strength is about 50 g/cm.sup.2. Other observations (not presented) show that, for a gel strength less than 20 g/cm.sup.2, the gel does not form, the solution of liquid coproduct flows in the rearing unit, and consequently the larvae become stuck and die.

[0308] d2) Effect of the Gelling Agent on the Consumption of the Gels by the Larvae

[0309] The results given in Table 12 below show that for enriched gels of an equivalent strength (about 50 g/cm.sup.2), the time for complete consumption of the gel is comparable: between 10 and 11 hours. The gelling agent therefore does not have a significant effect on the appetence of the gels. Thus, various gelling agents may be used for the purposes of the invention to achieve similar results for the consumption of the gel by the larvae.

TABLE-US-00019 TABLE 12 Effect of the gelling agent on the consumption of enriched gels Strength Consumption time Weight gain Gelling agent (g/cm.sup.2) (h) (%) Xanthan Carob 56.92 9.7 (+/0.7) 9.8% Xanthan Guar 42.09 10.3 (+/1.3) 10.2% Agar-Agar 47.24 11.3 (+/0.3) 10.2%