FR3131181A1 - METHOD FOR THE INDUSTRIAL TREATMENT OF ARTHROPOD LARVA, AND IN PARTICULAR LIVE INSECT LARVA - Google Patents

Abstract

The present invention relates to a method and an installation for the industrial treatment of arthropod larvae, and in particular live insect larvae, comprising a step of separating the larvae and the frass; a step of devitalizing the larvae; Characterized in that said step of devitalizing comprises immersing said larvae in water at a temperature above 50°C; said step of devitalizing being followed by a step of separating the larvae from the water. Abstract Figure: Figure 1

Description

METHOD FOR INDUSTRIAL TREATMENT OF ARTHROPODS LARVAE, AND IN PARTICULAR LIVING INSECT LARVAE Field of the invention

The present invention relates to the field of industrial breeding of arthropod larvae, in particular insects and more specifically Diptera, for the purposes of food production.

The invention relates more particularly to the field of insect breeding, in particular to the black soldier fly.

Insects have a number of characteristics that make them well suited for use in animal feed. Insects contribute high protein content, while being rich in other beneficial nutrients such as fats, minerals and vitamins. Protein concentration levels in insect meals intended for animal feed vary between 55% and 75%. Insects are characterized by a higher feed conversion rate and can therefore become a very valuable feed source for livestock. Insects are a natural component of the diet of animals such as carnivorous fish and poultry (for example, insects can provide up to 70% of trout's dietary requirements).

Furthermore, these products also have a well-balanced nutritional profile to meet human dietary needs.

These considerations have led to the development of automated large-scale production of foods from the breeding of arthropods, and more particularly insects, in industrial sites organized into complementary spaces specialized in egg-laying, hatching, breeding, the collection of mature animals and their treatment to extract the compounds of interest.

These industrial sites must be optimized to allow the industrialization of large volumes of larvae. One of the critical steps concerns the treatment of live larvae in order to valorize them, in particular the larvae of the black soldier fly Hermetia Illucens. The larvae are valued in the form of protein meal and quality oil. The rearing environment in which the larvae evolve at the end of their growth cycle, called frass, is also valued. Frass is made up of a mixture of larval droppings and residues of uneaten, dried and fermented substrate.

This processing stage occurs after stages of egg production in industrial conditions, collection of eggs laid by female insects and concentration of larvae for their rearing because it is appropriate to group them as homogeneously as possible, in batches. of neonate larvae all having the same stage of maturity in a given batch. Generally, egg-laying takes place in a cage confining the flies in a closed space in which collectors with egg-laying surfaces, for example grooved plates, are placed, on which the females deposit the eggs. These collectors are recovered to then allow the eggs to hatch giving rise to neonate larvae which are then injected into a nutrient medium in breeding modules. These neonate larvae are then raised in multi-stage growth modules to reach maturity before being transformed into nutrients and food, which is the step that is the subject of this patent.

The present invention relates to a method and system for transforming mature larvae into a nutrient-rich paste which can then be further processed to extract compounds of interest, including proteins and oily substances. The present invention relates in particular to the first stages of this process, namely the separation of the larvae and the frass and the devitalization of the larvae.

State of the art

Various solutions are known in the state of the art for treating insects and worms on an industrial scale to produce nutrients, which can then be used in the preparation of food products or animal feed.

We know in particular the patent FR3070001 describing an entomoculture process implementing a step consisting of feeding insect larvae with organic waste and a devitalization step of the insect larvae with a view to transforming them into a valuable product, characterized in what the devitalization stage is carried out by subjecting the larvae to a gradual increase in pressure up to a hygienization stage during which the pressure is between 3,000 bars and 7,000 bars.

This process operating at very high pressures is very expensive in terms of energy and equipment.

European patent EP2953487 describes another method for converting fresh insects or worms into nutrient streams, comprising the steps of first reducing the size of the insects or worms to obtain an insect or worm pulp, then heating the paste at a temperature of 70-100°C, then subject the heated pulp to a physical separation step, thus obtaining a fat fraction, an aqueous protein fraction and a fraction containing a solid, provided that the process does not include enzymatic treatment of the pulp, in which the aqueous protein fraction and the fraction containing the solid are dried.

This solution involves a step of chopping live larvae as a killing solution. This solution is not satisfactory because it is impossible to ensure that a crusher or chopper kills 100% of the larvae. In fact, it can happen that a larva passes through the mesh or between knives. In addition, killing larvae without a prior washing step reduces the quality of the final product because frass particles may remain stuck to the larvae.

Patent application EP3240905A1 describes a process for preparing a beetle powder comprising at least 67% by weight of proteins and at least 5% by weight of chitin, comprising the following steps of devitalizing the beetles, pressing the beetles to obtain a press cake, and grinding the press cake. This solution is specific to beetles.

Patent application WO2021167449 describes a method for producing eviscerated insects, such as black soldier fly larvae and mealworms, preferably live insects for the separation of insects or treated eviscerated insects into at least a fraction of fats and/or at least a fraction of proteins.

This solution aims to stimulate the evisceration of the insect and the release of the intestinal contents of the insect into the liquid with the aim of providing a liquid comprising the intestinal contents of the insect on the one hand, and the living insect on the other hand.

Disadvantages of the prior art

The solutions of the prior art are not completely satisfactory. Solutions providing for chopping of live larvae as a slaughtering step can lead to difficulties such as the lack of guarantee that 100% of the larvae are slaughtered. In addition, grinding the larvae without a prior washing step can lead to a reduction in the quality of the final product through the presence of frass residue. In addition, they lead to a health risk through contamination and degradation of the ground materials by the residual enzymatic activity of the larvae fractions, altering certain compounds of interest.

Another disadvantage of prior art solutions is the energy cost of the treatments proposed.

Solution provided by the invention

The invention relates in its most general sense to a process for the industrial treatment of arthropod larvae, and in particular of live insect larvae, and more specifically of dipteran larvae, in particular of black soldier fly larvae comprising:

• a step of separating the larvae and the frass, for example by sieving, by granulometry, or by aeraulic separation;
• a stage of devitalization of the larvae;

characterized in that:

• said devitalization step comprises immersing said larvae in water at a temperature above 50°C;
• said devitalization step being followed by a step of separating the larvae and the water.

Advantageously, the larvae are first immersed in a tank of water, called a mixing tank, before circulating the water and larvae mixture in a heat exchanger to heat said mixture to a temperature above 55°C, in particular between 55°C. °C and 95°C (preferably between 55°C and 60°C) for a period of between 2 and 15 minutes.

Preferably, the water used is purified to remove residual frass particles and then reinjected in whole or in part into the mixing tank.

According to an alternative embodiment, the industrial treatment process for arthropod larvae, and in particular insect larvae, and more particularly dipterans according to the invention, comprises a step of grinding the larvae after immersion in hot water and after separation of the larvae and said hot water.

According to other alternative embodiments, the process for industrial treatment of arthropod larvae, and in particular live insect larvae, according to the invention:

• comprises a step of separating the larvae and the frass carried out by granulometry in two stages: a first step to separate the larvae from the frass particles whose size is less than the size of the larvae then a second step to separate the larvae from the pellets or plates frass whose size is larger than the size of the larvae;
• comprises a first step of separating the larvae and the frass particles whose size is less than the size of the larvae carried out by a first piece of equipment comprising a filter cloth with periodically variable mesh sizes;
• comprises a second step of separating the larvae and the pellets or patches of frass whose size is greater than the size of the larvae, constituted by a second treatment by a circular screen;
• comprises a devitalization step constituting a final step of separation of the larvae and the frass by additional treatment in the aqueous phase.

According to other characteristics:

• said step(s) of separating the larvae and the frass comprise the recovery of the frass and the transfer to equipment for valorizing said frass;
• said larvae devitalization step is ensured by heat treatment at a selectable temperature between 55°C and 95°C via a double concentric tube exchanger in which the larvae and water mixture circulates in the inner tube and in which the hot water circulates in the outer concentric tube;
• said heat exchanger is supplied with hot water by a first source of hot water at a temperature below 100°C and/or by a second source of superheated water at a temperature above 100°C;
• the process includes, after the devitalization step, a step of recovering hot water loaded with frass in which the larvae have been devitalized via a draining screen.

The invention also relates to an installation for the industrial treatment of arthropod larvae, and in particular live insect larvae and more specifically Diptera larvae, in particular black soldier fly larvae, comprising equipment for separating larvae and droppings. by sieving, and equipment for devitalizing the larvae characterized in that:

• said devitalization equipment is constituted by a heat exchanger having a primary circuit with an inlet for receiving a mixture of water and larvae coming from a mixing tank and a secondary circuit supplied by a fluid at a temperature greater than 60° or even greater than 100 °C and preferably between 75 and 100°C, to heat said mixture;
• the outlet of said primary circuit opening into equipment for separating larvae and water;
• the water then being purified to remove residual frass;
• said installation comprising a hydraulic circuit for reinjecting all or part of the purified water into the supply circuit of said mixing tank.

Advantageously, said equipment for separating larvae and frass comprises a filter cloth with periodically variable mesh sizes.

According to a variant, the installation comprises a weighing belt transporting the larvae between said equipment for separating larvae and frass by sieving and said mixing tank.

Detailed description of a non-limiting example of production

Other characteristics and advantages will emerge from the following description of the invention, description given by way of example only, with reference to the appended drawings in which:

there represents the diagram of the treatments which are the subject of the invention.

General principle of the invention

The invention is based on a gentle and rapid devitalization step preserving the biological integrity of the larvae, limiting animal mistreatment and optimizing the energy cost of treatments to produce quality nutrients of interest with little loss. Indeed, this devitalization step induces an “automatic” washing of the larvae which increases the quality of the protein because the dry mass coming from the frass is drastically reduced.

Fresh larvae are produced in the rearing area. The object of the present invention concerns devitalization, the devitalization zone is considered to be in the breeding zone in the health approval. After devitalization, the rest of the process takes place in the processing zone into which only slaughtered animals can enter and which must be physically separated from the breeding and devitalization zone.

The larvae evolve and grow directly in their breeding substrate, in multi-stage modules. During the growth of the larvae, the substrate is consumed by the larvae and the rearing medium gradually evolves towards frass. When the larvae have reached their optimal size and age for their nutritional profile and when the rearing medium is ready to be sieved, the multi-stage modules are emptied by turning and the contents are conveyed to a sorting area by conveyors chain. The larvae and their frass are therefore transferred from an automatic turner to a hopper located above a separating sieve.

There represents the functional architecture of the treatments applied to the contents of the multi-stage modules of growth of black soldier fly larvae Hermetia Illucens.

A feeding station (1) ensures the transfer of the contents of the multi-stage growth modules to the devitalization chain of living larvae. This content consists of a mixture of live larvae and frass. Frass corresponds to the culture medium and therefore also contains insect droppings, as well as the rest of the substrate not consumed by the larvae.

This mixture is poured onto a sieve (2) ensuring separation by a vibrating filter mesh by discrimination according to the particle size. The finest particles, namely powdery frass particles, fall by gravity to be recovered by a recovery treatment (10) with a view to use, for example, as fertilizer intended for agricultural operations. The largest particles, namely the larvae and any pellets or clumps of frass, are transferred to a weighing belt (3) making it possible to determine the mass of larvae to be treated.

A circular screen (4) ensures a second separation between the living larvae and the pellets or agglomerated frass plates. These pellets or agglomerated frass plates are also recovered by a recovery treatment (10).

After this second step of particle size separation, it may happen that residual frass particles remain in contact with the larvae, the larvae being relatively sticky. The live larvae and residual frass particles are then immersed in a mixing tank (5) containing hot water. The mixture of live larvae, residual frass particles and water is transferred to an exchanger (6) powered by a membrane pump to bring it to a temperature between 55°C and 95°C (preferably between 55°C and 60°C). C) in order to devitalize the larvae. The mixture of devitalized larvae, residual frass particles and water is then poured onto a sieve-drain (7) separating the devitalized larvae which are transferred to a crusher (8), and the charged effluents (water and residual frass particles) which are evacuated to the dirty compartment of a settling tank (11) aimed at separating the residual frass particles and the water.

The settling tank is separated into two compartments by a separation plate: the dirty compartment and the clean compartment. The frass settles in the dirty compartment and the contents of the bottom of the dirty compartment, heavily loaded with frass, are transferred to a frass press (12) which separates the frass particles and purifies the water. The frass thus recovered is then transferred to the recovery equipment (10). The water thus purified in the frass press is sent to the settling tank in the clean compartment. The water on top of the dirty compartment is sufficiently clean since it is less loaded with frass, the latter having settled. This water from the dirty compartment flows to the clean compartment above the divider plate. A pump draws water from the clean compartment, this clean water is then reinjected in whole or in part into the mixing tank. Thus, water losses are drastically limited and the water used is entirely or partly recycled and reused.

The devitalized and cleaned larvae coming from the sieve-drainer (7) are transferred to a crusher (8) using an eccentric rotor pump. The dough thus obtained is then subjected to additional treatments of hygienization and separation of the compounds of interest and in particular the protein flour and the oil.

Issue of the process of devitalization of live larvae and the transformation process

These devitalization and transformation processes present four main issues.

• Extract as much protein as possible from insect larvae. This involves maximizing extraction yields and exploiting all available proteins. The extraction yield is defined by the ratio between the quantity of protein in the flour divided by the quantity of protein initially contained in the larvae.
• Produce the highest quality protein flour possible. Quality is mainly measured with three criteria:
  • The protein level, ie the protein concentration (typically between 60 and 70%). This criterion of purity of the solid fraction of the extraction often requires finding a compromise with the extraction yield.
  • The digestibility of the protein for the animals that will consume it. Digestibility is generally measured in vivo during R&D tests in real conditions. Methods for estimating in vitro digestibility also exist. Digestibility is strongly linked to the transformation process undergone by the larvae and in particular the time/temperature pair applied. This couple must be minimized to maximize digestibility (in order to avoid a “cooking” effect of the proteins).
  • The palatability of the protein for the animals that will consume it. Palatability is also measured during in vivo tests. Oxidation is one of the elements influencing palatability.
• Produce a protein flour meeting regulatory bacteriological criteria. For an innovative product such as protein or insect oil, the health validation method is called “Method 7”. This involves proving over 30 consecutive production batches that the products from the processing line demonstrate the absence of Clostridium Perfringens, Salmonella and Enterobacteria. The reduction of these bacteria is ensured by the application of a heat treatment i.e. a time/temperature couple. In order to maximize the reduction of bacteria, this time/temperature couple must be maximized. However, a compromise must be found between health constraints and digestibility constraints.
• Produce competitive products with limited processing costs:
  • CAPEX: investments in minimal equipment;
  • OPEX: operating costs mainly come from energy costs linked to the transformation process.

Details on separation of live larvae and droppings

The frass and larvae mixture can be sorted by particle size on an inclined trampoline sieve (2). Indeed, frass is mainly made up of a wet powder, with a particle size of the order of a millimeter. The larvae can be compared to cylinders with a diameter between 3 and 5 mm and a length between 8 and 12 mm. It is therefore relevant to use separation by particle size: a sieve.

The sieve technology used to separate the larvae from the frass is a trampoline sieve. The mesh of the sieve evolves with a trampoline effect, that is to say that the mesh extends then relaxes, creating a rebound effect of the material. This sieve is particularly suitable for clogging materials such as frass which is a powdery material with a variable humidity between 40 and 60% RH.

The screening cloths are made of a mesh with meshes approximately 30mm long and with a width of between 2 and 4mm. The trampoline effect of the sieve produces a slight deformation of the meshes preventing the meshes from becoming clogged as well as the formation of crust. These canvases are driven into a box by an eccentric shaft and the box is closed by a cover. A sluice at the bottom of the hopper upstream of this sieve allows the larvae and frass mixture to be distributed evenly across the entire width of the sieve.

The larvae remain above the mesh and travel along the entire length of the sieve. The powdered frass passes through the mesh gradually along the length of the sieve. The frass is collected under the sieve and is valued separately.

The width, length, inclination and mesh size of the sieve are chosen to:

• ensure the treatment of the nominal instantaneous flow of incoming material (larvae and frass);
• ensure the best possible separation between the larvae and the frass.

On equipment like sieves, there is often a compromise to be made between purity and yield. There is also a fraction to favor. Indeed, the purer the fraction of larvae, the more risk there will be of having larvae in the frass. Conversely, if yield (quantity of larvae) is preferred, then we must prevent larvae from passing through the frass. The choice made is to favor the yield (quantity of larvae) and the purity of the frass.

Weighing belt step (3)

The sieved larvae are collected on a weighing belt (3) positioned perpendicular to the sieve (2). Thus the larvae which fall at the end of the sieve over the entire width of the sieve (2) are collected on a weighing belt (3). The weighing belt (3) is equipped with load cells which allow the flow of larvae circulating on the belt to be measured. This makes it possible to monitor the performance of the breeding: it is then possible to link a flow rate and a sieving time to a batch of returned multi-stage breeding modules. Then, it is possible to calculate the biomass produced on this batch of modules. By correlating this data with various production data on the rearing area, performance indicators such as the average yield per module and the conversion rate of nutrient materials used for larvae rearing are calculated.

Flow measurement is also important for the rest of the process.

Purification stage and equipment (4)

During the growth of the larvae in the rearing zone, the substrate can evolve in different ways depending on several parameters such as:

• airflow in the storage area;
• ambient humidity and temperature near the modules;
• the age of the larvae at the start of their formation into modules;
• the number of larvae in the modules;
• the composition of the raw materials constituting the substrate.

Even if these parameters are controlled as finely as possible, it may happen that the substrate does not systematically evolve in the same way depending on these parameters. The substrate may evolve, creating patches or large balls of frass. These pellets are impossible to eliminate in the first separation step (sieving via the trampoline sieve) because they have a size greater than or equal to the size of the larvae. In the case of frass plaques or crusts, the observation is similar: they do not pass through the perforations of the mesh and are found in the larvae fraction. This is why a second purification step is planned to separate the larvae from unwanted elements which are larger than the larvae.

This is a second particle size separation. A circular screen is used with a mesh larger than the size of the larvae. The larvae pass through this mesh and the large particles remain above the mesh and are removed to the side of the circular screen.

The separation between the larvae and large particles is positioned downstream of the first trampoline screen which makes it possible to eliminate the powdery frass because the flow rate entering this second screen is significantly reduced and makes it possible to limit the size and cost of the equipment. In fact, the quantity of powdered frass is much greater than the quantity of frass in the form of plates or pellets.

Method and equipment for devitalization of larvae (5, 6)

The larvae fall by gravity from the circular screen into a parallelepiped mixing tank (5). The larvae are mixed with water in a controlled proportion depending on the flow rate of larvae measured on the weighing belt. Water is used for several reasons.

Firstly, water serves as a transport vector to make it easier to handle and transfer the larvae by pumping to the following stages of the process.

Water also serves as a thermal vector to thermally devitalize the larvae and thus ensure that 100% of the larvae have been devitalized.

The water is also used to finish cleaning the larvae and is a third stage of purification. Indeed, the larvae are relatively moist on the surface and “grains” of frass can be found stuck to their surfaces. In this case, the sieving step using the trampoline sieve is not effective because this stuck frass remains attached to the larvae. In water, frass can detach and pass into the water phase.

Under the mixing tank, a membrane pump transfers the larvae and water mixture to the devitalization exchanger (6). The pump technology chosen makes it possible to maintain the larvae in complete integrity and not to damage them during this transfer stage.

The membrane pump allows the larvae to circulate to the devitalization exchanger and also through the devitalization exchanger. The larvae devitalization stage is carried out by heat treatment at a selectable temperature between 55°C and 95°C. The exchanger chosen is a double concentric tube exchanger. The larvae and water mixture circulates in the inner tube. Hot water circulates in the outer concentric tube providing the energy required to raise the temperature of the larvae and water mixture, without contact between the hot water and the larvae and water mixture.

The length of the exchanger is determined to ensure the temperature rise at nominal flow rate. Hot water can come from two different networks:

• a water network at 60°C;
• a superheated water network between 105 and 120°C.

At the outlet of the devitalization exchanger, the larvae and water mixture is passed into an inclined plane draining screen (7). Separation is very easy here because it involves separating the larvae from the hot water in which the larvae have been devitalized. The water passes through the mesh of the flat sieve. The water also washes away residual frass that was washed away while cleaning the larvae. The devitalized larvae remain above the mesh of the flat sieve and are directed to the next stage of the process: grinding.

The frass-laden water separated from the devitalized larvae is collected in the dirty compartment of a settling tank. This tank, which separates the water from residual frass particles, is separated into two compartments by a separation plate: the dirty compartment and the clean compartment. The frass settles in the dirty compartment and the contents of the bottom of the dirty compartment, heavily loaded with frass, are transferred to a frass press (12) which separates the frass particles and purifies the water. The frass thus recovered is then transferred to the recovery equipment (10). The water thus purified in the frass press is sent to the settling tank in the clean compartment. The water on top of the dirty compartment is sufficiently clean since it is less loaded with frass, the latter having settled. This water from the dirty compartment flows to the clean compartment above the divider plate. A pump allows water to be drawn from the clean compartment of the tank to reinject it in whole or in part into the mixing tank. This allows you to:

• limit water consumption;
• limit energy consumption. The water is in fact still hot when it is recycled, which limits the energy needs required by the devitalization exchanger.

To supply the frass press (12), a pump transports dirty water from the dirty compartment of the settling tank to the frass extraction press. The connection supplying the pump is judiciously chosen where the frass concentration is highest and where the water is dirtiest. The pump feeds the frass press which extracts the frass particles by pressing the water against a sieve. The frass is then transferred to the frass recovery equipment (10) and the water is purified. The frass is squeezed out well with the press and comes out at a humidity of around 40 to 50%. Little water is therefore lost.

Furthermore, the material balance of water is adjusted. In fact, a small proportion of water is lost in the treatment sequence.

• The drainage of the larvae via the draining sieve is not perfect: a small fraction of water is evacuated with the larvae and therefore leaves the circuit.
• As temperatures can be high, a small fraction of water is evaporated, particularly at the level of the draining sieve where the mixture of devitalized larvae and water is projected onto the sieve mesh.
• When purifying water in the frass press, depending on the efficiency of the press, a small amount of water is also discharged into the frass.
• In addition to water purification by extraction of frass, deconcentration makes it possible to renew the water in which the larvae are devitalized to prevent it from over-concentrating in the mixing tank. A purge valve at the bottom of the clean compartment in the settling tank is open for x seconds every y minutes (x and y being adjustable parameters). Clean water from the network is then automatically added once the purge valve is closed. Deconcentration is mainly used to remove frass particles which are completely diluted in water and which are very difficult to remove by the press.

The material balance is adjusted by maintaining a constant level in the separation tank. If too much water is lost, then the level will tend to decrease. A supply of clean water at 55°C into the clean compartment of the separation tank is then triggered to supplement. Conversely, if there is too much water in the circuit, the water in the dirty compartment is purged to restore the correct water material balance.

Grinding stage and equipment (8)

The larvae devitalized by heat treatment and drained in the draining screen are then collected at the outlet of the draining screen in a hopper which feeds an eccentric rotor pump. The pump is a monobloc pump, horizontally mounted. The pump pushes the whole devitalized larvae into a macerator grinder. The larvae are then crushed into several pieces. After grinding the product changes consistency and becomes a grainy paste.

The devitalization zone and the transformation zone are separated by a wall for regulatory constraints. At the end of the grinding process, the devitalized and crushed larvae cross the wall separating the two zones. The larvae pass through a second crusher using the same technology as the crusher in the devitalization zone.

The function of this second crusher is to ensure maximum particle size. The larvae are then transferred into a launching tank, that is to say a small agitated tank of 4 m ³ which makes it possible to create a buffer between the rearing, sieving and devitalization zones and the hygienization and devitalization zone. additional treatments.

Claims (15)

- Process for the industrial treatment of arthropod larvae, and in particular live insect larvae, comprising:

• a step of separating the larvae and the frass;
• a stage of devitalization of the larvae;

Characterized in that

• said devitalization step comprises immersing said larvae in water at a temperature above 50°C;
• said devitalization step being followed by a step of separating the larvae and the water.

- Process for the industrial treatment of arthropod larvae, and in particular live insect larvae, according to claim 1, characterized in that the larvae are previously immersed in a tank of water before circulating the water and larvae mixture in a heat exchanger for heating said mixture to a temperature between 55°C and 95°C and preferably between 55°C and 60°C for a period of between 2 and 15 minutes. - Process for the industrial treatment of arthropod larvae, and in particular live insect larvae, according to claim 2, characterized in that the water used is purified to remove residual frass particles then reinjected in whole or in part into the mixing tank. - Process for industrial treatment of arthropod larvae, and in particular live insect larvae, according to claim 1 characterized in that it comprises a step of grinding the larvae after immersion in hot water and after separation larvae and said hot water. - Process for the industrial treatment of arthropod larvae, and in particular live insect larvae, according to claim 1, characterized in that said step of separating the larvae and the frass is carried out by particle size distribution in two stages: a first stage for separate the larvae from the frass particles whose size is less than the size of the larvae then a second step to separate the larvae from the frass pellets or plates whose size is greater than the size of the larvae. - Process for the industrial treatment of arthropod larvae, and in particular live insect larvae, according to claim 5 characterized in that said first step of separating the larvae and the frass particles whose size is less than the size of the larvae is carried out by a first piece of equipment comprising a filter cloth with meshes of periodically variable dimensions. - Process for the industrial treatment of arthropod larvae, and in particular live insect larvae, according to claim 5 characterized in that said second step of separating the larvae and the pellets or frass plates is carried out by a circular screen. - Process for the industrial treatment of arthropod larvae, and in particular live insect larvae, according to claim 5 characterized in that the devitalization step constitutes a final step of separation of the larvae and the frass by an additional phase treatment watery. - Process for the industrial treatment of arthropod larvae, and in particular live insect larvae, according to claim 1, 5, 6, 7 or 8 characterized in that said step(s) of separating the larvae and the frass include recovery frass and transfer to equipment for recovering said frass. - Process for industrial treatment of arthropod larvae, and in particular live insect larvae, according to claim 2 characterized in that said step of devitalization of the larvae is ensured by heat treatment at a temperature selectable between 55°C and 95°C °C via a double concentric tube exchanger in which the larvae and water mixture circulates in the inner tube and in which the hot water circulates in the outer concentric tube. - Process for the industrial treatment of arthropod larvae, and in particular live insect larvae, according to the preceding claim, characterized in that said heat exchanger is supplied with hot water by a first hot water source at a temperature below 100 °C and/or by a second source of water superheated to a temperature above 100°C. - Process for the industrial treatment of arthropod larvae, and in particular live insect larvae, according to claim 1 characterized in that it comprises, after the devitalization step, a step of recovering the hot water loaded with frass in which the larvae were devitalized via a draining sieve. – Installation for the industrial treatment of arthropod larvae, and in particular live insect larvae, comprising equipment for separating larvae and droppings by sieving, and equipment for devitalizing the larvae
Characterized in that:

• said devitalization equipment is constituted by a heat exchanger having a primary circuit with an inlet for receiving a mixture of water and larvae coming from a mixing tank and a secondary circuit supplied by a fluid at a temperature above 60°C to heat said blend ;
• the outlet of said primary circuit opening into equipment for separating larvae and water;
• the water then being purified to remove residual frass;
• said installation comprising a hydraulic circuit for reinjecting all or part of the purified water into the supply circuit of said mixing tank.

– Installation for the industrial treatment of arthropod larvae, and in particular live insect larvae according to claim 13, characterized in that said equipment for separating larvae and frass comprises a filter cloth with mesh of periodically variable dimensions. – Installation for the industrial treatment of arthropod larvae, and in particular live insect larvae according to claim 13, characterized in that it comprises a weighing belt transporting the larvae between said equipment for separating the larvae and the frass by sieving and said mixing tank.