Gel containing liquid by-products from the agricultural industry and use of said gel for rearing insects

Abstract

The present invention relates to a gel for use as a source of water and / or nutrients for rearing insects, comprising 90-99.6% by weight of an aqueous base, the aqueous base containing at least 25% by weight of liquid by-products from the agricultural industry based on the total weight of the aqueous base, 0.3-2% by weight of a gelling agent, and 0.1-5% by weight of a preservative, the weight percentages of the aqueous base, the gelling agent, and the preservative being expressed relative to the total weight of the gel.

Description

[Technical field]

[0001] The present invention relates to insect nutrition, in particular to providing insects with water in the form of a gel. The present invention further relates to a nutrition regime, a method for preparing said gel and its application, in particular in insect rearing. [Background technology]

[0002] Industrial insect farming is growing rapidly and represents a major challenge for future animal and human nutrition, particularly as an alternative source of animal protein.

[0003] However, the industrialization of insect farming, particularly of the brown rice beetle (Tenebrio molitor), is under constant development and has proven to be very complicated for those skilled in the art.

[0004] Tenebrio molitor larvae are particularly valuable because they require little food and water to develop in their natural environment.

[0005] However, in industrial rearing, breeders must ensure that larvae grow well and constantly gain weight. It has been found that watering plays an important role in the proper growth of larvae. Therefore, it is necessary to optimize the nutritional regime, especially the water supply, according to the actual nutritional requirements of the larvae, and to be able to adjust the correct amount of water and nutrients according to the situation.

[0006] Furthermore, the water requirement for insects is generally of the order of 2 kg of water to produce 1 kg of mature insects (larvae ready to kill). Therefore, on an industrial scale, this represents a large volume of water that must be provided and properly managed. Indeed, poor water management can result in either poor growth, if the amount of water is inadequate, or increased insect mortality problems, mainly due to increased microbial risks and / or insect immobilization risks, if water is added to the rearing medium.

[0007] To date, rearing media for insect larvae are constituted, for example, by a nutrient medium, such as wheat bran, and contain fresh fruits and vegetables as a source of water. Water can also be supplied to the insects via atmospheric water or by direct wetting of the substrate.

[0008] However, these media do not always provide satisfactory growth and / or acceptable mortality rates.

[0009] In fact, these media generally have at least one of the following drawbacks: very limited water supply, the inability to assess the exact amount of water introduced / to be introduced into the rearing medium, excessive wetness or stickiness of the medium which promotes the growth of mold, complex management of water requirements, difficult waste management, which is generally a source of microbiological risks, limited water supply for industrial rearing.

[0010] There is therefore a need for a nutritional regime that is inexpensive, easy to implement, and allows both optimal growth and controlled mortality of the larvae.

[0011] Studies carried out by the inventors have made it possible to demonstrate that the supply of water in the form of a particular gel makes it possible to overcome the aforementioned drawbacks. Summary of the Invention

[0012] The present invention therefore relates to a gel comprising: - 90-99.6% by weight of an aqueous base, said aqueous base containing at least 25% by weight of liquid by-products from the agricultural industry, based on the total weight of the aqueous base; - 0.3 to 2% by weight of a gelling agent, as well as - 0.1 to 5% by weight of a preservative, Including, The weight percentages of the aqueous base, gelling agent and preservative are expressed relative to the total weight of the gel; The gel has a water content of more than 50% by weight based on the total weight of the gel. Concerning gel.

[0013] The invention will be better understood with reference to the following drawings and with reference to the following examples, given by way of illustration: [Brief description of the drawings]

[0014] [Figure 1a] Figure 1a is a diagram showing the growth and mortality rates of Tenebrio molitor larvae reared on gels containing liquid by-products from different agricultural industries (two solubles from wheat, distillery solubles from cereals, and distillery residue); [Figure 1b] Figure 1b corresponds to the growth curve of Tenebrio molitor reared on gel containing liquid by-products from the agricultural industry described in Figure 1a; [Figure 1c] Figure 1c is a diagram showing the feed conversion ratio FCR (also called consumption index) calculated for mealworm depending on the liquid by-products from the agricultural industry in the form of gels incorporated into its nutritional regime; [Diagram 2] FIG. 2 comprises FIG. 2a and FIG. 2b, in which FIG. 2a is a table showing comparative nutritional regimes including liquid by-products from wheat and corn from a starch mill, dried or freeze-dried, and FIG. 2b comprises two charts showing the results obtained in terms of growth and feed FCR obtained for the different comparative nutritional regimes described in FIG. 2a; [Diagram 3]FIG. 3 includes FIG. 3a and FIG. 3b, where FIG. 3a is a table showing comparative nutritional regimes including liquid by-products from starch production from dried or freeze-dried wheat, and FIG. 3b includes two charts showing the results obtained in terms of growth and feed FCR obtained for the different comparative nutritional regimes described in FIG. 3a; [Figure 4] FIG. 4 comprises FIG. 4a and FIG. 4b, in which FIG. 4a is a table showing comparative nutritional regimes including liquid by-products from wheat and corn from a starch mill in wet form or in the form of a gel, and FIG. 4b comprises two charts showing the results obtained in terms of growth and feed FCR obtained for the different comparative nutritional regimes described in FIG. 4a; [Diagram 5] FIG. 5 includes FIG. 5a and FIG. 5b, in which FIG. 5a is a table showing comparative nutritional regimes including liquid by-products from wheat and corn from a starch mill in wet form or in the form of a gel, and FIG. 5b includes two charts showing the results obtained in terms of growth and feed FCR obtained for the different comparative nutritional regimes described in FIG. 5a; and [Figure 6] FIG. 6 shows the evaluation of the mechanical properties of gels enriched with solubles from wheat with incorporation of 0.30%, 0.50% and 0.70% of gelling agent (xanthan-carob mixture) of Example IV, performed using a TA-XT Plus texturometer (Stable Micro Systems, TA.XT Plus, Surrey, France) and its "Exponent" analysis software (measurement of gel strength as a function of the distance traveled by a cylindrical probe used to apply pressure to the surface of the gel). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] In this application, all numerical values ​​given are understood to be inclusive unless otherwise stated.

[0016] The inventors have in fact shown that a water supply in the form of a gel comprising an aqueous medium, said aqueous medium containing at least 25% by weight of liquid by-products from the agricultural industry relative to the total weight of the aqueous medium, provides good absorption of water and nutrients by the insects, resulting in good growth, while reducing production costs by utilizing by-products from the agricultural industry. Furthermore, the use of a gel as a source of water advantageously makes it possible to stabilize the medium from a microbiological point of view and to protect the insects from the possibility of immobilization. The use of liquid by-products in the form of a gel as a source of water and nutrients also makes it possible to supply the insects with nutrients having a good nutritional content, since these nutrients are not subjected to an industrial drying step that may degrade the nutrients. Furthermore, liquid by-products from the agricultural industry are abundant and also have a low price. Moreover, these liquid by-products are efficiently converted by certain insects, in particular by the mealworm.

[0017] Preferred insects for factory farming are, for example, from the orders Coleoptera, Diptera, Lepidoptera, Orthoptera, Hymenoptera, Dictyoptera, in particular the suborder Blattoptera, including Isoptera and Mantoptera together, Phasmoptera, Hemiptera, Heteroptera, Ephemeroptera and Mecoptera, preferably Coleoptera, Diptera, Orthoptera, Lepidoptera, Blattoptera; or mixtures thereof.

[0018] Preferably, the insects are from the group consisting of: mealworm, Hermetia illucens, Galleria mellonella, Alphitobius diaperinus, Zophobas morio, Blattera fusca, Tribolium castaneum, Rhynchophorus ferrugineus, Musca domestica, Chrysomya megacephala, Locusta migratoria, Schistocerca gregaria, Acheta domestica, Samia serrata, and others. ricini) or mixtures thereof, and even more preferably, is Tenebrio molitor.

[0019] More preferably, the present invention relates to insect species having grinding mouthparts, such as species belonging to the orders Coleoptera, Lepidoptera (especially in the larval stage), or Hymenoptera; or to insect species having piercing mouthparts, such as species belonging to the orders Diptera or Hemiptera.

[0020] The gel is suitable for species belonging to the order Coleoptera, such as scarab beetles, ladybirds, stag beetles, leaf beetles, chafers, weevils, ground beetles, and more specifically species of the Tenebrionidae. The gel regime is typically used for rearing mealworms (mealworms).

[0021] Advantageously, the gel is adapted for the larval stages of the above mentioned insect species.

[0022] A by-product is a substance that is inevitably produced during the production of a desired product.

[0023] In particular, the by-products to which the present invention relates are liquids. By "liquid" is meant a by-product that is in liquid form under normal atmospheric conditions and at ambient temperature. In particular, this means that the by-product is one that is obtained directly at the end of an industrial process without a drying step.

[0024] More specifically, the liquid by-product is an aqueous by-product that includes soluble materials. Preferably, the soluble materials present in the liquid by-product are proteins and / or carbohydrates, such as sucrose and / or lactose, more preferably proteins and carbohydrates. The soluble materials may also include soluble fiber.

[0025] Advantageously, the liquid by-product comprises at least 90% by weight of soluble matter relative to the total weight of dry matter, in other words, the by-product comprises less than 10% by weight of insoluble matter relative to the total weight of dry matter.

[0026] By "agricultural industry" it is meant more specifically the starch production, potato starch production, malting, bioethanol production, sugar production, fermentation, brewing, distilling industries and the dairy industry.

[0027] The liquid by-products of these industries are obtained from waste liquids, and more specifically from the water produced during the various manufacturing processes that are the objective of these industries.

[0028] Starch production and potato starch production aim to separate the plant components, in particular starch or potato starch, respectively. Malt production aims to germinate barley and prepare malt by a process called malting.

[0029] In starch production and potato starch production, the water produced during the manufacturing process, for example during soaking of raw materials in water, is referred to as "solubles".

[0030] There are different types of solubles depending on the raw materials used in this production process: wheat, corn, potato, pea, barley, cassava solubles.

[0031] Examples of solubles include CORAMI® (derived from wheat), SOLULYS® (derived from corn), sold by ROQUETTE, or AMYSTEEP 424® (derived from corn), sold by TEREOS.

[0032] Preferably, the solubles are selected from wheat solubles and / or corn solubles.

[0033] There are also distillate solubles. The latter are obtained by fermentation-distillation of solubles during the bioethanol production process. They are therefore distillate solubles from wheat, maize, pea, cassava, barley and distillate solubles from cereals (e.g. wheat, maize, barley).

[0034] Another liquid by-product can result from this bioethanol production process: yeast cream.

[0035] As will be explained in more detail hereinafter, yeast cream can be obtained in other ways, for example by fermentation, distillation or brewing, or in a bioprocess which produces propanediol, succinic acid or polyhydroxyalkanoates.

[0036] In the case of cream from yeast resulting from the bioethanol production process, it advantageously originates from active or inactive yeast recovered by filtration at the end of the fermentation process.

[0037] As examples of yeast creams one can find in particular yeast creams from the alcoholic fermentation of wheat solubles.

[0038] Distillers solubles often include the yeast used in fermentation and the (undiluted) solubles.

[0039] Examples of distillers solubles include ALCOMIX® (derived from wheat) sold by TEREOS, CORAMI® BE (derived from wheat) sold by ROQUETTE, PROTIWANZE® (derived from wheat), and also distillers solubles derived from wheat, corn and barley.

[0040] The sugar industry aims to extract sugar from sugar beets or sugar cane. The sugar industry produces several types of liquid by-products, in particular mother liquors and molasses.

[0041] Mother liquor and molasses correspond to the syrupy residues obtained after crystallization of the liquid formed during sugar production. The sugar content is higher in mother liquor than in molasses.

[0042] There are different types of molasses and mother liquor depending on the raw materials utilized in the sugar manufacturing process: sugar cane molasses, sugar beet molasses, sugar cane mother liquor, and sugar beet mother liquor.

[0043] Examples of molasses include sugar cane molasses, such as that sold by PRIMEAL, and sugar beet molasses.

[0044] The fermentation, distillation and brewing industries use microorganisms to produce, by growth (e.g. yeast, especially baker's yeast), biological substances such as amino acids (glutamic acid, lysine), organic substances (enzymes) or alcohol.

[0045] Alcohol can be produced starting from raw materials of various origins, for example by fermentation of fruits (grapes, sugar beet, sugar cane), cereals (wheat, corn) or cassava.

[0046] These industries produce several types of liquid by-products, including stillage and yeast cream.

[0047] Vinasses are liquid by-products obtained from the fermentation of the mash after extraction of the compounds of interest.

[0048] Examples of stillages include the following products: VINASSE 60® (stillage from the production of baker's yeast) and VIPROTAL® (sugar beet syrup stillage from fermentation to produce baker's yeast), sold by LESAFFRE, PRL 364® (sugar beet syrup and glucose stillage from fermentation to produce glutamic acid) and SIRIONAL® (sugar beet syrup and glucose stillage from fermentation to produce lysine), sold by AJINOMOTO.

[0049] Yeast cream represents a by-product obtained from the separation of the mash, for example by filtration and centrifugation after fermentation.

[0050] "Fermentation" means any process that uses microorganisms, such as yeast, bacteria and / or fungi, to transform raw materials.

[0051] As mentioned above, the yeast cream may contain microorganisms in active or inactive form, advantageously yeasts.

[0052] The dairy industry produces, among other things, cheese, butter, and cream.

[0053] Whey, also called milk serum, is a liquid by-product produced especially during cheese manufacturing. Whey exists in two forms, sweet whey and acid whey, and is rich in milk proteins and nutrients. Whey protein concentrate (WPC) in liquid form is an ingredient derived from whey by removing water, minerals and part of the lactose. Permeate is a by-product resulting from the production of milk or whey protein concentrate by ultrafiltration. Permeate contains soluble particles from milk or whey, salts and lactose. The liquid permeate can be concentrated and used before drying.

[0054] The liquid by-product is therefore advantageously selected from the list comprising: solubles from cereals, solubles from corn, 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 corn, distillers solubles from peas, distillers solubles from cassava, distillers' residues, molasses, yeast cream, whey and its concentrated derivatives, in particular permeates, or mixtures thereof.

[0055] The use of these liquid by-products in insect nutrition makes it possible to reduce the costs associated with nutrition while promoting good growth of insects by providing by-products with good nutritional properties. In fact, by-products in liquid form allow better growth than dry by-products. This can be explained by the fact that the industrial drying methods used in the manufacture of dry by-products affect the nutritional content of the by-products so obtained. Thus, liquid by-products have a better nutritional content than dry by-products.

[0056] Advantageously, the liquid by-product comprises a water content of more than 35% relative to the total weight of the by-product, preferably the water content is equal to or greater than 40%, more preferably equal to or greater than 50%.

[0057] Preferably, the liquid by-product is selected from the list comprising: solubles from cereals, solubles from corn, solubles from wheat, distillers solubles from cereals, distillers solubles from wheat, distillers solubles from corn, distillers bottoms, yeast cream, whey and its concentrated derivatives, in particular permeates, or mixtures thereof.

[0058] Advantageously, the aqueous medium comprises water and by-products from the agricultural industry. Preferably, the aqueous medium is constituted by water and by-products from the agricultural industry.

[0059] Preferably, the aqueous base has a total water content comprised between 56 and 98.2% by weight, preferably between 60 and 95% by weight, more preferably between 70 and 90% by weight, based on the total weight of the aqueous base.

[0060] The gel comprises 0.3-2% by weight of gelling agent, preferably 0.5-1.5% by weight of gelling agent, the weight percentages being given relative to the total weight of the gel.

[0061] Preferably, the water content of the gel is more than 50% by weight relative to the total weight of the gel, preferably between 65 and 85% by weight relative to the total weight of the gel.

[0062] The presence of a preservative in the gel makes it possible to limit the growth of mold in the gel. Preferably, the content of preservative is comprised between 0.1 and 3% by weight, more preferably between 0.15 and 0.5% by weight, for example 0.3% by weight, relative to the total weight of the gel.

[0063] Advantageously, the preservative is chosen from preservatives usable in animal nutrition, and more particularly from the group constituted by: acetic acid, sodium acetate, formic acid, fumaric acid, citric acid, sorbic acid, potassium sorbate, calcium sorbate, propionic acid, sodium propionate, calcium propionate, benzoic acid, sodium benzoate, calcium benzoate, potassium benzoate, butyric acid, and the salts and acids corresponding to these molecules.

[0064] Preferably, the preservative is not a paraben.

[0065] According to a particular embodiment of the invention, the gel comprises: - 90-99.6% by weight of an aqueous base, the aqueous base containing at least 25% by weight of liquid by-products from the agricultural industry based on the total weight of the aqueous base, - 0.3 to 2% by weight of a gelling agent, as well as - 0.1 to 5% by weight of a preservative, said preservative being chosen from preservatives usable in animal nutrition, more particularly from the group consisting of acetic acid, sodium acetate, formic acid, fumaric acid, citric acid, sorbic acid, potassium sorbate, calcium sorbate, propionic acid, sodium propionate, calcium propionate, benzoic acid, sodium benzoate, calcium benzoate, potassium benzoate, butyric acid, and the salts and acids corresponding to these molecules; Including, The weight percentages of the aqueous base, gelling agent and preservative are expressed relative to the total weight of the gel; The gel has a water content of more than 50% by weight based on the total weight of the gel.

[0066] Preferably, the preservative is potassium sorbate or sodium propionate.

[0067] By-products from the agricultural industry are liquid at ambient temperature.

[0068] Preferably, the content of the aqueous base material is 95 to 99% by weight based on the total weight of the gel.

[0069] Advantageously, the aqueous medium contains at least 50% by weight of liquid by-products from the agricultural industry, based on the total weight of the aqueous medium.

[0070] Advantageously, the aqueous medium comprises water and at least 50% by weight, such as at least 75% by weight, of by-products from the agricultural industry. Preferably, the aqueous medium is constituted by water and at least 50% by weight, such as at least 75% by weight, of by-products from the agricultural industry.

[0071] According to certain embodiments of the present invention, if molasses is used, it is desirable to use a maximum amount of 55% by weight of molasses in the matrix.

[0072] According to another particular embodiment of the invention, when stillage is used, it is desirable to use a maximum amount of 70% by weight stillage in the base material.

[0073] According to a third particular embodiment of the invention, when the yeast cream is introduced into the aqueous medium, it is preferable for the yeast cream to be introduced by a mixture of by-products such that the amount of yeast cream does not exceed 25% by weight of the aqueous medium.

[0074] According to a particular embodiment of the invention, the aqueous medium comprises water and at least 95% by weight of by-products from the agricultural industry. Preferably, the aqueous medium comprises water and at least 95% by weight of by-products from the agricultural industry.

[0075] According to a particular embodiment of the invention, the aqueous medium consists of liquid by-products from the agricultural industry.

[0076] Preferably, the liquid by-product is selected from the list including: - solubles from cereals, solubles from maize, solubles from wheat, solubles from cassava, distillers' solubles from cereals, distillers' solubles from wheat, distillers' solubles from maize, distillers' solubles from cassava, yeast cream, whey and its concentrated derivatives, in particular permeates; or - mixtures of at least two by-products selected from cereal solubles, corn solubles, wheat solubles, cassava solubles, distillation solubles from cereals, wheat solubles, corn solubles, distillation solubles from cassava, yeast cream, whey and its concentrated derivatives, in particular permeate, yeast cream, stillage and molasses, is selected from.

[0077] Preferably, the aqueous base has a total water content comprised between 50 and 95% by weight based on the total weight of the aqueous base.

[0078] Preferably, the liquid by-product from the agricultural industry is a distillate solubles or a mixture of distillate solubles and another liquid by-product.

[0079] Advantageously, the distillers solubles are selected from the group constituted by: distillers solubles from wheat, distillers solubles from corn, and distillers solubles from cereals.

[0080] As mentioned above, the gels of the present invention also include a gelling agent.

[0081] Advantageously, the gelling agent is chosen from the group constituted by: agar, carrageenan, guar gum, calcium alginate, chitosan, pectin, xanthan gum, carob gum, gellan gum or mixtures thereof.

[0082] According to another particular embodiment of the invention, the gel comprises: - 90-99.6% by weight of an aqueous base, the aqueous base containing at least 25% by weight of liquid by-products from the agricultural industry based on the total weight of the aqueous base, - 0.3 to 2% by weight of a gelling agent selected from the group consisting of agar, carrageenan, guar gum, calcium alginate, chitosan, pectin, xanthan gum, carob gum, gellan gum or mixtures thereof, and - 0.1 to 5% by weight of a preservative, Including, The weight percentages of the aqueous base, gelling agent and preservative are expressed relative to the total weight of the gel; The gel has a water content of more than 50% by weight based on the total weight of the gel.

[0083] More specifically, the gel comprises: - 90-99.6% by weight of an aqueous base, the aqueous base containing at least 25% by weight of liquid by-products from the agricultural industry based on the total weight of the aqueous base, - 0.3 to 2% by weight of a gelling agent selected from the group consisting of agar, carrageenan, guar gum, calcium alginate, chitosan, pectin, xanthan gum, carob gum, gellan gum or mixtures thereof, and - 0.1 to 5% by weight of a preservative, said preservative being chosen from preservatives usable in animal nutrition, more particularly from the group consisting of acetic acid, sodium acetate, formic acid, fumaric acid, citric acid, sorbic acid, potassium sorbate, calcium sorbate, propionic acid, sodium propionate, calcium propionate, benzoic acid, sodium benzoate, calcium benzoate, potassium benzoate, butyric acid, and the salts and acids corresponding to these molecules; Including, The weight percentages of the aqueous base, gelling agent and preservative are expressed relative to the total weight of the gel; The gel has a water content of more than 50% by weight based on the total weight of the gel.

[0084] According to a particularly advantageous embodiment of the invention, the gelling agent is a mixture of xanthan and carob gum, a mixture of xanthan and guar gum or is an agar gelling agent.

[0085] Advantageously, the gelling agent comprises a 50 / 50 mixture of xanthan gum and carob gum. By way of example, a gelling agent of this type is sold by Cargill under the name Flanogen® XL 12. Carob gum has the advantage of having an attractive effect on insect larvae, in particular on the larvae of the mealworm beetle.

[0086] According to a particular embodiment of the invention, the gel comprises yeast.

[0087] The yeast may be active or inactive.

[0088] "Inactive yeast" also means yeast extract and / or yeast flakes. "Yeast flakes" means the insoluble fraction of yeast, i.e. the yeast cell wall and yeast plasma membrane. It is therefore neither the whole yeast nor the cell contents of yeast, e.g. yeast extract. Yeast flakes have highly beneficial properties in animal or human health or as a food supplement for animals and humans.

[0089] Advantageously, the total yeast content of the gel is comprised between 0.5 and 20% by dry weight of yeast relative to the total weight of the gel, preferably between 3 and 15% by dry weight of yeast, preferably between 4 and 10% by dry weight of yeast.

[0090] The yeast may be derived from liquid by-products from the agricultural industry.

[0091] The by-product from the agricultural industry may in fact be a distillate soluble, which already contains yeast, or it may comprise a mixture of at least two liquid by-products from the agricultural industry, one of which is yeast cream.

[0092] Alternatively, the yeasts may be added in solid form, for example in the form of dried yeasts, or as probiotics as shown below: In the form of dried yeasts, they are introduced in a content comprised between 0.1 and 6% by weight, preferably between 1 and 5% by weight, relative to the total weight of the gel.

[0093] In addition to proteins, carbohydrates, soluble fiber and optional yeast, by-products from the agricultural industry may contain other nutrients of interest, such as minerals.

[0094] Advantageously, the sodium content of the by-product is greater than or equal to 1% relative to the total weight of the by-product.

[0095] Advantageously, the liquid by-product has a sodium content of more than 2% by weight relative to the total weight of the by-product.

[0096] However, too high a sodium content may be toxic to the larvae of the mealworm, preventing their proper development. Preferably, the by-product contains a sodium content of 1% to 5%.

[0097] The by-product advantageously contains a sulphuric acid content of less than 4% by weight of the total by-product. Too high a sulphuric acid content may be toxic to the larvae of the mealworm moth and prevent their proper development. Preferably, the by-product contains a sulphuric acid content of less than 3%, preferably less than 2%, more preferably less than 1%.

[0098] Advantageously, the gel according to the invention may further comprise calcium.

[0099] According to another embodiment, the yeast may come from the addition of a probiotic to the gel.

[0100] If a probiotic is added to the gel, this is introduced for example in a content comprised between 0.1 and 8% by weight, preferably between 1 and 5% by weight, relative to the total weight of the gel.

[0101] An example of a probiotic is the yeast LB 2245® from the company LALLEMAND. These yeasts also contain vitamins and minerals.

[0102] The gel according to the present invention may further contain 0.001 to 0.5% by weight of a vitamin relative to the total weight of the gel, for example 0.001 to 0.1% by weight of a vitamin relative to the total weight of the gel.

[0103] The vitamins may be introduced in the form of a vitamin-enriched composition, for example in the form of a "premix."

[0104] Advantageously, the premix comprises vitamins chosen from the group constituted by: vitamin A, vitamin B1 (thiamine), vitamin B2 (riboflavin), vitamin B3 (nicotinamide), vitamin B5 (pantothenic acid), vitamin B6 (pyridoxine), vitamin B8 (biotin), vitamin B9 (folic acid), vitamin B12 (cobalamin), vitamin C, vitamin PP (niacin), vitamin D3 (cholecalciferol), vitamin E, vitamin K2 (menaquinone), vitamin K3 (menadione), or precursors and derivatives thereof.

[0105] There are a number of commercially available premixes, such as the premix AIN Vitamin Mixture 76 sold by MP Biomedicals, LLC.

[0106] The premix may also contain choline, cholesterol, carnitine and / or inositol, as well as minerals and / or trace elements.

[0107] Thus, besides the aforementioned sodium and calcium, the gel may advantageously contain minerals chosen from the group constituted by: iron, copper, selenium, chromium, iodine, cobalt, manganese, fluorine, zinc, potassium, phosphorus, magnesium.

[0108] These minerals may also be derived from by-products from the agricultural industry or added via premixes, which may be vitamin premixes containing the above-mentioned minerals or mineral-only premixes. An example of a mineral premix is ​​the premix "Wesson Salt Mixture" sold by MP Biomedicals, LLC.

[0109] Advantageously, the vitamin premix is ​​added to the gel in a content comprised between 0.1 and 5% by weight relative to the total weight of the gel.

[0110] The gel according to the invention advantageously has a density of at least 30 g / cm2 , especially 30g / cm 2 , 40g / cm 2 or 50g / cm 2 , preferably 80 g / cm 2 The gel strength is

[0111] Indeed, insects can only tolerate certain textures: they must be able to easily cut the gel with their mouthparts and ingest the pieces, therefore the gel must be solid.

[0112] Advantageously, the gel strength is 40 g / cm 2 ~150g / cm 2 , especially 80g / cm 2 ~150g / cm 2 Preferably, the gel strength is 40 g / cm 2 ~100g / cm 2 , in particular at least 50 g / cm 2 , or even at least 90 g / cm 2 , more preferably at least 100 g / cm 2 The gel strength is measured using a texturometer.

[0113] Therefore, the gel is not sticky or adhesive, therefore the insects can move around on the gel without getting stuck, therefore this reduces insect mortality and reduces insects getting trapped in the gel.

[0114] Furthermore, the syneresis of the gel is advantageously between 0.1 and 5%, which can prevent excessive release of water and moisten the environment of the insects.

[0115] The syneresis of gels can be determined, for example, as indicated in G. BLANCHER (2009), Sciences du Vivant [Life Sciences], ENSIA (AgroParisTech). The measurement is carried out on a product stored for 24 hours at 4° C. by differential weighing on an analytical balance. Briefly, the product contained in a cup is weighed and then the surface liquid contents are removed by tilting the cup and then with an absorbent paper placed lightly on the surface of the product. A second weighing is then carried out. The syneresis is expressed as the percentage loss between the two weighings.

[0116] Advantageously, the gel has a suitable form to facilitate the access of the insects to the water. It may, for example, be 30 cm 3 ~1500cm 3 The gel unit (block) has a volume included in the above, for example a cube or a parallelepiped with a square base, or a cylinder, and has a length of the order of 0.5 to 15 cm, preferably 0.8 to 12 cm.

[0117] The present invention also relates to a nutritional system for insects comprising a gel and a feed: the gel is as described above, and the feed is an insoluble substrate, the insoluble substrate having a moisture content of not more than 55% by weight relative to the total weight of the insoluble substrate; Regarding nutritional regime.

[0118] Thus, the nutritional regime according to the invention comprises two separate products and the feed is not contained in a gel.

[0119] Advantageously, the nutritional regime is used for rearing Tenebrio molitor larvae.

[0120] A substrate is said to be "insoluble" because it contains at least 60% by weight of insoluble matter relative to the total weight of dry matter, such insoluble matter being, for example, selected from the group consisting of wheat bran, rice bran, corn bran, corn germ cake, corn fiber, fiber of feed legumes, wheat middlings, distillers grains, barley rootlets (from malt), skins from tubers, potatoes, pea pulp, sugar beet pulp.

[0121] The content of nutrients, water, and insoluble substrate in the gel is determined so that sufficient amounts of nutrients and water are provided to the larvae of the mealworm.

[0122] Advantageously, the insoluble substrate has a moisture content of less than 45% and preferably less than 25% relative to the total weight of the insoluble substrate.

[0123] The advantage of using a gel for water supply is that it allows the reduction of microbiological risks, in particular the risk of mold. Indeed, water supply in the form of a gel makes it possible to limit the water content of the insoluble substrate.

[0124] The present invention also relates to a method for preparing a gel according to the invention, comprising: - forming a liquid compound by mixing: i. 90-99.6% by weight of an aqueous base, the aqueous base containing at least 25% by weight of a liquid by-product from an agricultural industry based on the total weight of the aqueous base, the aqueous base being at a temperature that allows dissolution of the gelling agent; ii. 0.3 to 2% by weight of a gelling agent, and iii. 0.1 to 5% by weight of a preservative; The weight percentages of the aqueous base, the gelling agent and the preservative are expressed relative to the total weight of the liquid compound. - cooling the liquid compound such that the compound is below a second temperature, at which the compound gels; The present invention relates to a method comprising the steps of:

[0125] The aqueous base material, the liquid by-product from the agricultural industry, the preservative and the gelling agent are as defined above for the gel according to the invention.

[0126] The method for preparing a gel according to the invention comprises in particular the following steps: - forming a liquid compound by mixing: i. 90-99.6% by weight of an aqueous base, the aqueous base containing at least 25% by weight of a liquid by-product from an agricultural industry based on the total weight of the aqueous base, the aqueous base being at a temperature that allows dissolution of the gelling agent; ii. 0.3 to 2% by weight of a gelling agent, and iii. 0.1 to 5% by weight of a preservative; The weight percentages of the aqueous base, the gelling agent and the preservative are expressed relative to the total weight of the liquid compound. - releasing the liquid compound; - in-line cooling the liquid compound such that the liquid compound has a second temperature, at which the liquid compound gels; - Step of transfer to distribution lines; - cutting the gelled compound into blocks as it leaves the dispensing line; Includes.

[0127] "Brought to a temperature allowing dissolution of the gelling agent" refers in particular to a step of heating the aqueous medium containing the by-product. This step is carried out by any means available for this purpose. Advantageously, the aqueous medium is heated to a temperature between 60°C and 100°C, in particular between 60°C and 85°C, for example of the order of 80°C; preferably, the temperature is such that it is sufficient to dissolve the gelling agent without affecting the nutritional content of the liquid by-product.

[0128] In particular, by "liquid compound" is understood a compound that is in liquid form at the heating temperature, and in fact it is intended that this liquid compound gels upon cooling.

[0129] By "drawing off" is meant the step of extracting the liquid compound formed by the first step of mixing the aqueous base with the gelling agent and preservative from the vat in which it is located. Advantageously, the drawing off step makes it possible to draw off an appropriate amount of the homogeneously mixed liquid compound to provide the insects with an amount of gel appropriate to their requirements for water and nutrients.

[0130] "In-line cooling" means a step of cooling along the device for producing the gel by means provided for this purpose. The released liquid compound is cooled while being conveyed between the vat in which it is located and the environment of the insects. This in-line cooling brings the liquid compound to a temperature below its gelling temperature, which may be, for example, a temperature of the order of 40°C. More generally, the compound thus gelled is brought to a temperature compatible with the use for which it is intended. For example, in the case of feeding and watering insects, the compound to be dispensed at a temperature close to that temperature after in-line cooling is brought to a maximum temperature of 25°C at the outlet from the in-line cooling. The in-line cooling may be carried out in one go or in several stages by stepwise and successive cooling stages.

[0131] The transfer step corresponds to the conveying of the gel from the cooling zone to the cutting zone, carried out by means of carriers provided for this purpose, advantageously at a temperature below 25° C. in order to maintain good cohesion of the gel.

[0132] The cutting-up step corresponds to a step of cutting up the gel. Advantageously, the cutting is carried out by mechanical cutting means making it possible to cut the gel according to the insects' requirements for water and nutrients.

[0133] Due to the in-line gelling of the compound after release in liquid form and cutting into blocks directly as it leaves the distribution line, the gel is produced on demand and continuously. The handling of the gel and its storage (in the form of gel) are eliminated, which in fact eliminates the problems associated with it. The risk of contamination or bacterial development is greatly reduced, since the gel is dispensed immediately after the compound is formed and leaves the distribution line. Also, in the context of insect rearing farms, the size of the block at the outlet can be precisely and continuously adjusted to the requirements.

[0134] The present invention further relates to the use of a gel according to the invention as a source of water and / or nutrients for rearing insects.

[0135] In particular, the gel according to the invention is used as a water and / or nutrient source, advantageously as a water and nutrient source, for the industrial rearing of insects.

[0136] The provision of a water source is essential for the proper development of insects. For the same amount of water provided (30% of the larvae's weight), mealworm larvae grow 48% faster in a gelled water source compared to water directly mixed with the substrate. Their individual weight gain relative to dry matter is also 64% higher.

[0137] Also, even when insects are reared at high densities, such as those used in facilities for industrial production, the use of the gel improves larval development relative to the use of carrot: indeed, the growth rate of larvae under these conditions is significantly higher for larvae reared on the gel.

[0138] Therefore, providing sufficient water to the insects is an important factor for rapid and efficient development of the larvae, which also allows a significant increase in productivity in insect farms, especially in Mealworm farms.

[0139] This also allows for better control over determining the amount of water provided.

[0140] The gel according to the invention also makes it possible to provide beneficial nutrients.

[0141] Advantageously, the gel is used for rearing mealworms, in particular for rearing mealworm larvae.

[0142] Finally, the present invention relates to the use of liquid by-products from the agricultural industry in the form of a gel as a source of water and / or nutrients, advantageously as a source of water and nutrients, for rearing insects, in particular for the industrial rearing of insects.

[0143] The use of liquid by-products from the agricultural industry advantageously provides greater control in determining the amount of water provided, as discussed above, as well as the supply of beneficial nutrients that promote insect growth while reducing the risk of mortality. EXAMPLES

[0144] Example I: Examples of gels according to the invention A. Products used in the gel according to the present invention a) Soluble -Solubles from corn SOLULYS 048E®, marketed by ROQUETTE. SOLULYS corresponds to a concentrated solution of solubles from corn obtained in the first step of the fractionation of the grain in the wet process for the production of starch. This concentrated solution contains 48% by weight of dry matter relative to the total weight of the solution, as well as 44% by weight of protein and 24% by weight of lactic acid, the last two weight percentages being expressed relative to the total weight of dry matter of the solution. AMYSTEEP 424®, sold by TEREOS. This composition of solubles from corn contains 42.5% by weight of dry matter relative to the total weight of the composition and 44% by weight of protein relative to the total weight of dry matter of the composition.

[0145] -Wheat solubles CORAMI®, sold by ROQUETTE. It corresponds to the solubles from the starch extraction obtained after the steeping and refining steps in the starch mill process. This composition of wheat solubles contains 29% by weight of dry matter relative to the total weight of the composition.

[0146] b) Distillation solubles -Distillate solubles from wheat ALCOMIX®, sold by the company TEREOS. This composition of wheat solubles contains about 20% by weight of dry matter relative to the total weight of the composition and about 28% by weight of protein relative to the total weight of dry matter of the composition. PROTIWANZE®, sold by the company CROPENERGIES. This distillers' solubles from wheat contains 27% by weight of dry matter relative to the total weight of distillers' solubles and 27% by weight of protein relative to the total weight of dry matter of distillers' solubles. CORAMI BE®, marketed by ROQUETTE. This distillers solubles from wheat contains 32% by weight of dry matter relative to the total weight of distillers solubles and 32% by weight of protein relative to the total weight of dry matter of distillers solubles.

[0147] -Distillers solubles from grains Distillers solubles derived from wheat, corn and barley, supplied by the company CROPENERGIES.

[0148] c) Yeast cream Yeast cream from wheat, supplied by TEREOS.

[0149] d) Distillation residue VINASSE 60®, sold by LESAFFRE. This stillage contains 60% by weight of dry matter relative to the total weight of stillage and 60% by weight of protein relative to the total weight of dry matter of the stillage. VIPROTAL®, sold by LESAFFRE. This stillage contains 60% by weight of dry matter relative to the total weight of stillage and 44% by weight of protein relative to the total weight of dry matter of the stillage. PRL 364®, sold by AJINOMOTO. This stillage contains 70% by weight of dry matter relative to the total weight of stillage and 70% by weight of protein relative to the total weight of dry matter of the stillage. SIRONAL®, sold by AJINOMOTO. This stillage contains 66% by weight of dry matter relative to the total weight of stillage and 52.8% by weight of protein relative to the total weight of dry matter of the stillage.

[0150] e) Molasses SUGARCANE MOLASSES, sold by PRIMEAL. This molasses contains 75% by weight of dry matter relative to the total weight of molasses and 5% by weight of protein relative to the total weight of dry matter of the molasses. BEET MOLASSES, sold by CRISTAL UNION. This molasses contains 75% by weight of dry matter relative to the total weight of molasses and 14% by weight of protein relative to the total weight of dry matter of the molasses.

[0151] f) Probiotics Yeasts LB 2245®, sold by LALLEMAND and having the characteristics set out in Table 1 below:

[0152] [Table 1]

[0153] g) Vitamin Premix Vitamin Premix PX SHRIMP V 0.5, marketed by MIX SCIENCE, has the following characteristics as shown in Table 2:

[0154] [Table 2]

[0155] B. Formulation of the Gel of the Present Invention

[0156] [Table 3] [Table 4] [Table 5] [Table 6] [Table 7] [Table 8] [Table 9]

[0157] C. Gel Preparation The above gel can be prepared as follows.

[0158] By-products from the agricultural industry(s) and optionally water are heated to a temperature above 80° C. in a stirred vat and then mixed with the other mixture ingredients: optional probiotics and premix, with at least one gelling agent and with at least one preservative in given proportions. The mixture thus obtained is then gradually returned to ambient temperature so as to form a gel.

[0159] Example II: Effect of different gels according to the invention on the development of Tenebrio molitor larvae Four agricultural by-products were tested: two wheat solubles (SB1 and SB2), vinasse (VF), and grain solubles (SC) obtained from wheat, corn, and barley.

[0160] A gel was formed according to Example I, which consisted of the following: 99% by weight of an aqueous base, based on the total weight of the gel, said aqueous base containing 25% by weight of each of the aforementioned agricultural by-products, based on the weight of the aqueous base, and 75% by weight of water, based on the weight of the aqueous base, 0.7% Flanogen XL12 (Cargill®), a 50 / 50 mixture of xanthan gum and carob gum, and 0.3% potassium L-sorbate.

[0161] A control gel was also formed and consisted of the following: water, 0.7% by weight Flanogen XL12 (Cargill®) and 0.3% by weight potassium L-sorbate, weight percentages being based on the total weight of the gel.

[0162] The mealworm larvae used in each series of experiments were derived from the same population originating from the laboratory breeding station of Ynsect in Evry at two different times.

[0163] The experiment was started with 10 grams of larvae after 48 hours of fasting, each weighing approximately 20 mg.

[0164] Larvae were cultured at 0.63 g / cm in clear plastic jars (dimensions: 4 × 4 × 7.5 cm) with a square base. 2 were reared at the optimal density.

[0165] In each diet, insect weight was adjusted to 10 grams by random selection of individual samples to restore optimal density.

[0166] The experiment lasted for 14 days and was carried out in the dark in a climate chamber to control the temperature at 24°C and the relative humidity at 60%. Tenebrio molitor larvae were fed ad libitum twice a week with the basal medium and the gel obtained as described above.

[0167] At the end of the experiment, the medium was weighed to assess the growth rate and mortality of the larvae reared in this manner.

[0168] To calculate the daily growth rate, it is necessary to determine the theoretical total growth and correct for the effects of serial dilutions. For this, the theoretical larval biomass (Mcumul) was again estimated and for each time point data (t) was obtained from the weighing of the larval mass (ML) according to the following formula:

[0169]

number

[0170] 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:

[0171]

number

[0172] To estimate mortality, the average apparent mortality rate was calculated for each day during each data collection period. Daily mortality was determined by dividing the number of deaths counted by the number of days between two feedings.

[0173] The results obtained are presented in FIG. 1a.

[0174] It is noted that by adding a gel containing the by-products to the larval rearing medium, it is possible to increase larval growth compared to a medium containing a gel composed only of water. Moreover, the addition of such a gel can advantageously reduce larval mortality compared to the control (gel composed of water) value.

[0175] It is noted in Figure 1b that the biomass of the feeding medium increases (from 10 g to 35 g) over the 14-day culture. The increase in biomass in the experiment carried out in the presence of gel containing by-products is greater than that in the control experiment carried out in the presence of gel containing only water (a difference of about 8 g).

[0176] Feed conversion ratios FCR were also calculated (by the method shown in Table 3 below) for all of the experiments carried out. The results are shown in Figure 1c. It can be seen that the feed conversion ratios in the experiments carried out in the presence of by-products are less than or equal to the feed conversion ratios obtained for the control.

[0177] In conclusion, the use of the by-product in gel form as a source of nutrients and water is particularly advantageous for growing mealworm larvae, providing improved growth compared to gels constituted with water.

[0178] Example III: Advantages of the gel according to the invention for the development of Tenebrio molitor larvae Duplicate experiments were carried out based on nutritional regimes consisting of by-products from two starch mills, firstly from wheat and maize (Plant A) and secondly from wheat (Plant B).

[0179] The objectives of each of these experiments were (1) to evaluate the effect of industrial drying on the nutrient content of the by-products, and (2) to test the use of liquid by-products for performance in rearing mealworms, particularly by incorporating them into a gel that is a simultaneous source of nutrients and water.

[0180] a) Biological materials and rearing conditions The mealworm larvae used in each series of experiments came from the same colony originating from Ynsect's laboratory rearing station in Evry and were collected at two different times.

[0181] The experiment was started with 10 grams of larvae after 48 hours of fasting, each weighing approximately 20 mg.

[0182] Larvae were cultured at 0.63 g / cm in clear plastic jars (dimensions: 4 × 4 × 7.5 cm) with a square base. 2 were reared at the optimal density.

[0183] In each diet, insect weight was adjusted to 10 grams by random selection of individual samples to restore optimal density.

[0184] The experiment lasted for 2 weeks and was carried out in the dark in a climate chamber to control the temperature at 25°C and the relative humidity at 60%. Tenebrio molitor larvae were fed ad libitum twice a week with 11 g of food and the amount of gel adjusted according to the moisture content of the substrate (see preceding paragraph). In total, the substrate was renewed four times and the renewal events corresponded to different data collections.

[0185] b) Experimental Procedures and Data Collection Data were collected for each diet. Individuals were separated from the diet by manual sieving using the appropriate sieve mesh as a function of individual size. Dead individuals were removed and counted. Live individuals were also counted. Live larvae and residues (unconsumed diet, remaining gel and faeces) were weighed and a small portion (approximately 2 grams) was placed at 105°C for 24 hours and then weighed to determine dry matter.

[0186] The variables studied were daily growth rate (GR, calculated as described in Example II) and feed conversion ratio (FCR).

[0187] To calculate the FCR, it is necessary to know the weight of the feed consumed. However, the latter is hardly obtainable due to the difficulties of sieving, so that, even if possible, it is necessary to carry out calculations and intermediate experiments starting from the method of indirect calculation (verified in the laboratory), so that the apparent digestibility and its derived index, the rejection rate (RR), are constant throughout the experiment, in other words the weight of the resulting feces (or the weight of the faeces) is proportional to the weight of the feed ingested. Therefore, an experiment in which 10 grams of mealworm larvae completely consumed the feed was carried out for all treatments in order to obtain the RR. The formula for the calculation is given in the following table (Table 3).

[0188] [Table 10]

[0189] c) Evaluation of the impact of industrial drying on the nutrient content of by-products The treatments with codes ending with the letter S (A1S and A2S, B1S and B2S) correspond to nutritional regimes consisting of a gel composed only of water and a nutrient matrix, which corresponds to a liquid by-product dried by two drying methods: industrial drying and drying by freeze-drying.

[0190] Preparation of diets and gels The nutritional regime is formulated to comply with the ratio of given by-product products to dry matter for each starch mill investigated.

[0191] Other by-products from starch production included in the nutritional regime are: - Wheat bran (WB_A and WB_B), - soluble matter from wheat (SB_A) derived from starch extraction, - solubles from wheat derived from starch extraction, which are mixed with solubles and yeast from distillers (SB_B); WB_0 corresponds to wheat bran from milling.

[0192] The ingredients used at 100% in treatments A1S (CPT_A) and B1S (CPT_B) corresponded to the products sold by the starch mills (industrially dried on site) and were constituted by the liquid by-products dried by freeze-drying used in the respective nutritional regimes A2S (WB_A and SB_A) and B2S (WB_B and SB_B), the proportions of which were maintained for such nutritional regimes.

[0193] For each series, a "control" treatment was included (A0 and B0), consisting of a nutritional regime based on wheat bran from milling and a gel containing an aqueous base constituted by water.

[0194] Each treatment was replicated three times.

[0195] [Table 11] [Table 12]

[0196] All dry nutritional regimes were prepared separately before the start of the study and stored in a dry and stable environment. For procedures dried by lyophilization, the moist mixture of by-products was first placed at -80°C for 24 hours and then kept in a lyophilizer for 3 days.

[0197] All treatments received 11 grams of food per feeding, independent of their dry matter content.

[0198] Regarding the gel given to the mealworm larvae as a source of water, the gel corresponds to a piece composed of 0.75% Flanogen XL12 (Cargill, France), which is a mixture of xanthan and carob gum, 0.3% potassium sorbate and supplemented with water. For a dry substrate with a water content of 15% or less, 6 grams of water were provided by the gel.

[0199] result The nutritional regimes are shown in Figures 2a and 3a; the results are shown in Figures 2b and 3b for products from plant A and plant B, respectively.

[0200] As can be seen from these results, the feeding carried out on dry substrates (A1S) and (B1S) does not make it possible to obtain good yields in terms of growth and FCR, as do the feedings carried out on freeze-dried liquid substrates (A2S / Figure 2) and (B2S / Figure 3).

[0201] As a result, industrial drying is found to affect the nutritional content of the by-products used, therefore it is preferred to use the latter in their liquid form.

[0202] d) Use of liquid by-products, especially incorporated into gels, for their performance in rearing of mealworms. This procedure makes it possible to compare different uses of liquid by-products: mixed in a wet substrate (A3 and B3) or incorporated in a gel (A4, A5 and B4).

[0203] Preparation of diets and gels The nutritional regime is constructed to comply with the ratio of given by-product products to dry matter for each starch industry investigated.

[0204] By-products from starch production included in the nutritional regime are: - Wheat bran (WB_A and WB_B), - soluble matter from wheat (SB_A) derived from starch extraction, - solubles from wheat resulting from starch extraction, mixed with solubles and distiller's yeast (SB_B); - solubles from corn (SM_A) derived from the steeping process; - Corn germ cake (GM_A), and -Wet corn fiber (FM_A).

[0205] [Table 13] [Table 14] [Table 15] [Table 16]

[0206] All dry nutritional regimes were prepared separately before the start of the study and stored in a dry, stable environment.

[0207] All wet feeding regimes were prepared on the day of feeding to keep the moisture content of the substrate stable and to prevent microbiological contamination. Powdered potassium sorbate was also added to the substrate (0.3%) and mixed well. All treatments received 11 grams of food per feeding, independent of their dry matter content.

[0208] Concerning the gel given to the mealworm larvae, said gel corresponds to small pieces composed of 0.75% Flanogen XL12 (Cargill, France), which is a mixture of xanthan and carob gum, 0.3% potassium sorbate, and supplemented with water and / or liquid by-products (depending on the treatment). The amount of gel provided in the diet was adjusted as a function of the moisture content of the substrate to avoid excessive supply of water to the mealworm larvae. For dry substrates with a water content of 15% or less, 6 grams of water were provided by the gel.

[0209] For substrates with a water content greater than 15%, the amount of water to be supplied by the gel was calculated according to the following formula: [Weight of water in gel in grams] = -([Water content of substrate as percentage] / 15%) + 7

[0210] As before, the nutritional regime was designed to adhere to the ratio of by-products given on dry matter for each starch mill investigated.

[0211] For each series, a "control" treatment was included (A0 and B0) consisting of a nutritional regime based on wheat bran from milling and gel. WB_0 corresponds to wheat bran from milling.

[0212] Each treatment was replicated three times.

[0213] result The nutritional regime is shown in Figures 4a and 5a; the results are shown in Figures 4b and 5b for products from plant A and plant B.

[0214] A comparison of the feedings made on wet substrates containing by-products (A3) and (B3) with substrates containing the by-products in the form of a gel (A4, A5) and (B4) clearly shows that the growth rate as well as the FCR (which should be as low as possible) are better when the by-products are provided in the form of a gel.

[0215] This can be explained by the fact that a wet medium increases the mortality of the individuals. Supplying the by-product in the form of a gel therefore allows the supply of the by-product in a liquid form in which its nutritional content is preserved, without causing the risk of increased mortality that would result from the excess water content of the medium.

[0216] Example IV: -Evaluation of the effect of the percentage of gelling agent on the physical properties of the enriched gel and the consequences for larval consumption; - Investigation of different gelling agents on the strength of enriched gels for three levels of incorporation; -Consequences for larval consumption.

[0217] a) Preparation of gel The gels used in this study are shown in Table 10 below. The liquid by-products (solubles from wheat derived from starch extraction, mixed with solubles and distiller's yeast) are incorporated in the enriched gel at 99% to 99.4%, taking into account the addition of potassium sorbate at 0.3% and the gelling agent contents at 0.30%, 0.50% and 0.70% (by weight relative to the total weight of the gel). The gelling agents used are: a mixture of xanthan and carob gum (Flanogen XL12, Cargill France), a mixture of xanthan and guar gum (Algaia, France) and agar intended for the agri-food industry (Biocean, France). The enriched gels were produced at 80° C. for 15 minutes using an "Amicook" multifunctional food processor (Amicook Family gourmet, France). The enriched gels were processed at 137.4 cm 3 A volume of 78.5 cm was quickly poured into a cylindrical dish and then left at 4°C for 24 hours to set. All gels were 3 (height: 4 cm; diameter: 5 cm).

[0218] [Table 17]

[0219] b) Analysis of gel texture 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 allows 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 to press the surface of the gel until a maximum depression of 20 mm was reached after contact. The penetration speed was fixed at 1.6 mm / s and the withdrawal speed was fixed at 10 mm / s. Tests were carried out with gels enriched with solubles from wheat at concentrations of 0.30%, 0.50% and 0.70% of gelling agent (xanthan carob mixture). In Figure 6, the lower curve relates to a 0.30% incorporation of gelling agent, the middle curve to a 0.50% incorporation of gelling agent and the upper curve to a 0.70% incorporation of gelling agent.

[0220] The following texture parameters were determined from the graph in FIG. 6, which represents intensity as a function of distance traveled by the probe: - Gel strength (g / cm 2 ), which corresponds to the force required to break and pierce the gel. - deformation (mm), which corresponds to the distance traveled by the probe from first contact to the rupture of the gel, and - hardness, which corresponds to the ratio of the gel strength to its deformation.

[0221] c) Study of the consumption rate of the larval gel of the yellow mealworm, Tenebrio molitor The Mealworm larvae used in this experiment were from the same colony originating from the laboratory breeding station of Ynsect in Evry and were taken from the same batch at the same time. The larvae were fasted for 48 hours before the start and had an average initial weight of 33 mg. A fixed ratio of 0.5 g gel to 2.5 g larvae was placed in a clear plastic jar with a square base (dimensions: 4 x 4 x 7.5 cm). The enrichment gel was cut out using a punch and placed in the center of the jar to guarantee the same area of ​​access to the gel by the larvae.

[0222] The experiment was carried out in the dark in a climate chamber to control the temperature at 26°C and the relative humidity at 60%. Hourly observations were made until complete consumption of the gel. Once the gel was completely consumed, mortality and individual larvae weights were confirmed by counting and weighing.

[0223] d) Results d1) Effect of gelling agent concentration on the strength of enriched gel and consumption by larvae The results shown in Table 11 below show that the gel strength and hardness was 56.92 g / cm for 0.3%. 2 From 149.09g / cm for 0.7% 2 The gel deformation ability increases slightly with gelator concentration over a range of strengths from 0.01 to 0.1%, i.e., three times stronger for a 0.4% increase in gelator concentration.

[0224] [Table 18]

[0225] The results show that gel consumption time increases slightly with gelling agent concentration: 5 hours additional consumption time for gels with 0.7% gelling agent compared to gels at 0.3%. Larval mortality and weight gain are equal regardless of gelling agent concentration. Thus, the results show that gels enriched with liquid by-products have a gel strength of approximately 50 g / cm 2Other observations (not shown) indicate that the 20 g / cm2 granules are more likely to be consumed by mealworm larvae. 2 It has been shown that at gel strengths below this, the gel will not form and a solution of liquid by-products will flow into the rearing unit, resulting in entrapment and death of the larvae.

[0226] d2) Effect of gelling agent on gel consumption by larvae The results given in Table 12 below are for equal strength (approximately 50 g / cm 2 ) enriched gels, the time taken for complete consumption of the gel is comparable: 10-11 h. Therefore, the gelling agent does not have a significant effect on the appearance of the gel. Thus, various gelling agents can be used for the purposes of the present invention to achieve similar results for the consumption of the gel by the larvae.

[0227] [Table 19]

Claims

1. 1. A gel for rearing insects, comprising: - 90-99.6% by weight of an aqueous medium consisting of liquid by-products from the agricultural industry and optionally water, the content of said liquid by-products from the agricultural industry being at least 25% by weight relative to the total weight of the aqueous medium, and said liquid by-products from the agricultural industry being prepared without a drying step after it has been obtained from the agricultural industry, and said liquid by-products from the agricultural industry being selected from the group consisting of solubles from cereals, solubles from corn, 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 corn, distillers' solubles from peas, distillers' solubles from cassava, distillers' residues, molasses, yeast cream, whey and its concentrated derivatives, or mixtures thereof, - 0.3 to 2% by weight of a gelling agent, and - 0.1 to 5% by weight of a preservative, Including, The weight percentages of the aqueous base, gelling agent and preservative are expressed relative to the total weight of the gel; The gel has a water content of more than 50% by weight based on the total weight of the gel.

2. 2. The gel of claim 1, wherein the aqueous base contains at least 50% by weight of liquid by-products from the agricultural industry based on the total weight of the aqueous base.

3. 3. A gel according to any one of claims 1 to 2, wherein the liquid by-product from the agricultural industry is a distillation soluble or a mixture of a distillation soluble and another liquid by-product.

4. 4. A gel according to any one of claims 1 to 3, wherein the gelling agent is a mixture of xanthan and carob gum or a mixture of xanthan and guar gum.

5. A gel according to any one of claims 1 to 4, comprising yeast.

6. 6. A gel according to claim 1, further comprising 0.001 to 0.5% by weight of a vitamin, relative to the total weight of the gel.

7. At least 30 g / cm 2 7. The gel according to claim 1, having a gel strength of

8. A method for preparing a gel according to any one of claims 1 to 7, comprising the steps of: - forming a liquid compound by mixing: i. an aqueous medium consisting of liquid by-products from the agricultural industry and optionally water, with a content of said liquid by-products from the agricultural industry of at least 25% by weight relative to the total weight of the aqueous medium, and said liquid by-products from the agricultural industry are prepared without a drying step after they are obtained from the agricultural industry, and said liquid by-products from the agricultural industry are selected from the group consisting of solubles from cereals, solubles from corn, 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 corn, distillers' solubles from peas, distillers' solubles from cassava, distillers' residues, molasses, yeast cream, whey and concentrated derivatives thereof, or mixtures thereof, said aqueous medium being at a temperature allowing dissolution of the gelling agent; ii. 0.3 to 2 wt. % of a gelling agent; and iii. 0.1 to 5% by weight of a preservative; The weight percentages of gelling agents and preservatives are expressed relative to the total weight of the liquid compound. - cooling said liquid compound so that the compound is below a second temperature, at which the compound gels; A method comprising:

9. 8. Use of a gel according to any one of claims 1 to 7 as a source of water and / or nutrients for rearing insects.

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