WO2019030450A2 - Method of insect farming and of adding value to insect larvae, including a high-pressure larva hygienisation step - Google Patents

Abstract

The invention relates to a method of insect farming including a step of feeding organic waste to insect larvae and a step of killing the insect larvae in order to turn them into a value-added product, characterised in that the killing step is achieved by subjecting the larvae to a gradual pressure increase until a hygienisation step is achieved, in which step the pressure is between 3000 and 7000 bars.

Description

 A method of entomoculture and recovery of insect larvae, including a high-pressure larval hygienization step.

 The invention relates to the field of entomoculture. More specifically, the invention relates to a technique of recovery of organic waste, the latter being used to feed insect larvae themselves themselves valued.

 In the face of current environmental problems (overproduction of waste and scarcity of food resources), the state of the art has recently proposed natural solutions for feeding, with organic waste, insect larvae, and in particular, but not exclusively , larvae of the black soldier fly.

 The entomoculture technique is thus used as a sustainable valorisation tool to extract from these insects proteins, fats and other co-products.

 Thus, according to a known sector, a method of entomoculture takes place in the following general manner:

 the larvae are fed with organic waste (of various fruits and vegetables ...) collected locally;

 a natural fertilizer is on the one hand obtained from waste by a process of composting operated by the larvae;

 the larvae, on the other hand, are harvested after converting the nutrients of the substrate into body reserves in the form of proteins, lipids, vitamins, mineral salts and chitin.

 A large part of the larvae harvested is transformed in order to separate the different components, which will each be valued according to a specific use.

 The remaining larvae at the end of the process are recovered to give rise to a new generation of insects. A new cycle can then be started.

 Entomoculture is a particularly interesting industrial process for two reasons, namely:

 this process makes it possible to transform various organic waste into a stabilized fertilizer ready for use;

the process leads to the production of larvae with a high content of proteins, fats and other co-products that can be used in animal feed. However, the current techniques of entomoculture generate different disadvantages, and in particular:

 they do not make it possible to achieve sufficient productivity in the composting and / or larval growth phase, as regards the quantity of treated waste and larvae produced per unit time and area;

 they do not make it possible to finely separate the mature larvae from the organic substrate, or even to treat them effectively; they do not ensure hygienization of the larvae (destruction of micro-organisms and pathogenic substances) which makes it possible to guarantee the quality of the larvae and their conservation;

 they do not optimize the quality of the larvae in terms of digestibility of the protein and the preservation of the vitamin, minerals and essential trace elements in animal feed.

 Regarding the separation of mature larvae from their organic substrate, the most common current technique is to carry out a mechanical separation, using a separation grid: the substrate at the end of the cycle is dry and is in aggregates and is therefore retained by the grid. Of course, many substrate particles pass through the grid and thus remain mixed with the larvae to be valued, which is of course undesirable.

 For larval slaughter, several techniques are currently used, namely:

 scalding;

 fast drying;

 - freezing.

 All these techniques are detrimental to the quality of coproducts resulting from the valorization of the larvae, generating a process of deterioration of the material.

 Concerning entomoculture equipment, the most widespread are in the following form, including:

 - a climate-controlled room equipped with storage devices

containers in which the larvae and the organic substrate are placed.

The substrate may be provided at one time or in a fractional manner. Such equipment has a very low productivity, with a relatively high larval mortality rate.

 It has also been proposed equipment in the form of enclosures consisting of a rotatably mounted drum for accommodating a mixture of ground organic material and larvae.

 Such equipment is more advantageous than the previous ones, since rotation of the drum makes it possible to ensure a relatively continuous mixture of the organic waste with the larvae, which improves the yield and reduces the mortality of the larvae.

 However, the current equipment is designed for small scale installations. For the most part, it is difficult to handle, particularly with regard to the extraction of larvae from the drum.

 In addition, traditional drum equipment does not optimize composting conditions combined with those favoring the development of larvae.

 The invention particularly aims to overcome the disadvantages of the prior art.

 More specifically, the invention aims to provide a method and entomoculture equipment that allow to obtain nutritional extracts of insect larvae significantly richer than those obtained with the prior art.

 The invention also aims to provide such a method and such equipment that can increase the yield both in terms of recovery of organic waste in quantity of larvae to be valued.

 The invention also aims to provide such a method and such equipment that can achieve an installation with significant productivity gains.

These objectives, as well as others that will appear later, are achieved thanks to the invention which relates to an entomoculture method implementing a step of feeding insect larvae with organic waste and a step for killing insect larvae with a view to transforming them into a valuable product, characterized in that the slaughtering step is carried out by subjecting the larvae to a gradual increase in pressure up to a stage of hygienisation at during which the pressure is between 300 MPa and 700 MPa. As will become apparent later, the increase in pressure may range between 1 and 750 MPa, with a key step of between 300 and 700 MPa with regard to the hygienization of the larvae.

 Thus, thanks to the invention, the larvae are freed of their microbial load and other potential contaminants, this through the application of high pressure.

 In addition, any phytosanitary products present in the organic products can be degraded or "broken" (that is to say hygienized) by the application of high pressure. In addition, the high pressure leads to an optimization of the nutritional functions of the larvae, in particular:

 the cutting of certain peptide bonds increasing the digestibility of proteins and their preservation (drastic limitation of oxidation); increased oil conservation (drastic limitation of the oxidation / rancidity of oils (and more precisely of certain fatty acids such as polyunsaturates and monounsaturates) and improvement of the separation of lipid, protein and solid phases, the cuticle of larvae being better separated after the application of high pressure than without high pressure.

 In addition to the improved digestibility of the proteins of the larvae, the method according to the invention leads to an improved preservation of all the vitamins, minerals and trace elements present in the insect larvae, which is of interest for targeting foods. or special recipes containing such vitamins, minerals, and trace elements.

 The use of high pressure for slaughtering insect larvae will produce other particularly advantageous effects, among which:

 a better separation of chitin and a better purification / transformation into chitosan by biotechnological means, and in particular by enzymatic hydrolysis;

 a drastic drop in the odor emitted by the triturated insects, so less energy to purify the scented air;

 better purification of the oil from the larvae;

a better behavior of the oils from the larvae, avoiding to alter the pellets made with these oils (the conventional oils in contact with other materials altering and also altering the materials in contact, the pellet therefore being less efficient; conventional oils are combined with adjuvants such as ethoxyquin, which allow delimiting the deterioration / oxidation of the oils and more particularly, but not exclusively, polyunsaturated fatty acids).

 In the context of valorization of larvae raised with an entomoculture method according to the invention, the best preservations and digestibilities of the product resulting from the recovery result in beneficial effects of the animals fed with the recovery products, and in particular:

 a growth gain for the animal fed with the products resulting from the larvae raised with the method according to the invention;

 a qualitative gain in the flesh of the animals thus fed;

 a decrease in the medicinal product used in the breeding of the animals concerned, which may be manifested in animal welfare, since the ingredients of the larvae retain their "antimicrobial" characteristics;

 in general, a guarantee of the sanitary quality of the food product obtained.

 It should be noted that the slaughtering technique according to the invention has an ethical dimension both for the respect of the processed larvae and the quality of co-products from the recovery of treated larvae.

 According to an advantageous solution, the hygienisation step is carried out at least according to the following phases:

 pressure rise from 0.1 MPa to 100 MPa in 15 s;

 - pressure increase from 100 MPa to 500 MPa in 1 min and 15 s;

 pressure rise from 500 MPa to 600 MPa in 30 s;

 pressure rise up to 700 MPa and maintenance of pressure at 700

MPa for about 1 hour.

It has been observed that the pressure increase process according to the invention has the following effects:

killing of insects at + 0.030 seconds. action on vegetative bacteria: from 16 seconds at 100 MPa, and at +2 minutes and 8 seconds at 800 MPa: almost total inactivation for a maximum time of 60 min and a temperature between 19 ° C (ambient) and 100 ° C;

 action on yeasts / molds: from 36 seconds and up to 72 seconds, between 200 MPa and 400 MPa, from 19 ° C to 70 ° C and between 6 min and 60 min (under stabilized pressure);

 action on viruses: between 350 MPa and 600 MPa, 5 min to 15 min (in stabilized pressure) and between 4 ° C and 30 ° C;

 action on vegetative spores: between 200 MPa and 800 MPa, from 36 seconds and up to 128 seconds, from 5 minutes to 60 minutes (under stabilized pressure) and between 19 ° C. and 100 ° C.

 action on the enzymes: between 300 MPa and 900 MPa, from 48 seconds and up to 144 seconds, from 5 minutes to 60 minutes (in stabilized pressure) and between 19 ° C. and 60 ° C.

 - action on the oxidation of lipids: between 200 MPa and 600 MPa from 32 seconds and up to 96 seconds) at 20 ° C, and from 5 minutes to 60 minutes (in stabilized pressure), being acquired that the longer the time of pressurization is longer longer is conservation;

 action on carbohydrates (texture, gelation of monosaccharides and polysaccharides) leading to an easy separation of chitin: between 200 MPa and 600 MPa from 32 seconds and up to 96 seconds, from 5 minutes to 45 minutes (under stabilized pressure) and between 5 ° C to 45 ° C;

 action on vitamins: little influence on vitamins, vitamin preservation, trace elements and minerals,

action on the proteins: from 200 MPa up to 750 MPa from 32 seconds and up to 120 seconds, from 5 min to 60 min (in stabilized pressure) and between 5 ° C and 60 ° C, action on the structures secondary, tertiary and quaternary (improved digestibility, protein conservation, improved textures and organoleptic characteristics). According to a preferred solution, the slaughtering step comprises a step of falling asleep at a pressure of 0.12 MPa for a duration of a few hours. Such a stage of falling asleep makes it possible to conduct a method forming part of an ethical approach prior to the slaughter of the larvae.

 According to a preferred solution, the sleep stage is followed by the slaughter stage at a pressure greater than or equal to 0.2 MPa for a duration of approximately 1 minute.

 Thus, the larvae are killed while they are unconscious, this fast way.

 According to a particular embodiment, the slaughter stage is preceded by a step of bagging the larvae.

 In this case, the bagging step is conducted under a partial vacuum of between 90% and 99.9%

 Thus, the larvae once bagged will effectively undergo high pressure without the wall of the bag or bags significantly interfere with the application of pressure.

Other characteristics and advantages of the invention will appear more clearly on reading the following description of a preferred embodiment of the invention given by way of a simple illustrative and nonlimiting example, and the appended drawings among which:

 - Figure 1 is a block diagram of a waste treatment system by insect larvae, including an entomoculture method according to the invention.

 Figure 2 schematically illustrates a module for slaughtering and sanitizing insect larvae for the implementation of an entomoculture method according to the invention.

 Figures 3 to 5 schematically illustrate an enclosure for breeding insect larvae implemented in an entomoculture method according to the invention, respectively viewed in perspective, side and longitudinal section;

 FIG. 6 schematically illustrates an arm having means for controlling the temperature and / or humidity conditions inside an enclosure for larvae of insects;

Figure 7 schematically illustrates a breeding chamber associated with an arm supported by a support external to the enclosure; Figure 8 is a detail view of Figure 7;

 Figure 9 is a schematic representation of an example of implantation of a series of livestock enclosure.

 Referring to Figure 1, a waste processing and recovery of insect larvae comprises the following steps:

 storage of the raw material constituting waste to be treated (step E1), this waste may include vegetable organic matter (MOV), meat organic matter (MOC), organic matter derived from cereal co-product or organic waste constituting a mixture of vegetable organic matter and meat organic material which must then be specifically treated as a deconditioning step (step E2);

 the waste, regardless of the type of organic material listed above, then undergoes a milling step (step E3);

 depending on the insect larvae, a mixture comprising different fractions of the organic materials listed above is composed in a recipe preparation step (step E4);

 the substrate obtained at the end of step E4 is then introduced into a bioreactor, as well as the insect larvae (step E5).

 As an indication, the tank of the bioreactor is configured and sized to recover from 5 t to 15 t of organic matter (with different solids content from 20% to 60%) and to produce 0.5 t to 3 t of larvae. Harvesting insect at voracious or prepupal stage.

 The principle of the bioreactor is to make it possible to produce a modifiable digestate (having NPK and organic matter levels depending on the organic matter), with a regular particle size of between 1 mm and 3 mm. At the end of recovery, a mixture is recovered (having a moisture content of less than 50%, avoiding the use of drying after recovery), which can be easily sieved to separate the digestate larvae ready for extraction (step E6).

 The digestate is directed to a stabilization step (step E7) consisting of

place the material in an enclosure in which temperature and time are managed to eliminate a number of undesirable microorganisms, pathogens and other unwanted seeds. The time / temperature pair is preferably 7071 h. At the end of this stabilization step, a finished product is obtained (step E8).

 The insect larvae arrived at the voracious or prepupal stage are directed towards an extraction phase (their lipid phase, protein and solid), usually starting with a washing step (step E9). This step consists of ridding the larvae of any recovery residues (fine particles of organic matter, lice, mites, etc.)

 Stage E1 1 consists of a slaughter stage characterizing the entomoculture method according to the invention, this stage being carried out by subjecting the larvae to a gradual increase in pressure up to a stage of hygienisation during which the pressure is between 300 MPa and 700 MPa.

 The progressive pressure increase includes a sleep stage at a pressure of 0.1 MPa for a duration of a few seconds, followed by a slaughter stage at a pressure greater than or equal to 0.2 MPa for a duration of approximately 1 minute.

 Prior to the hygienization step and in particular at the slaughter stage, the larvae are packaged in sachets under a partial vacuum of between 90% and 99.9% during a bagging step.

 To perform the hygienization step, the equipment comprises a slaughter module capable of achieving a gradual increase in pressure to go to the hygienization step described above.

 With reference to FIG. 2, such a felling module 1 comprises:

 a watertight tank 10 intended to receive at least one flexible pouch P of larvae;

 filling means 12 of the vessel in an incompressible liquid, comprising a water reservoir 120 and a low pressure pump 121 connected by a conduit inside the vessel;

- Two movable walls 13, 14 one being open to introduce the pockets in the tank and the other being open to extract the pockets of the tank, all of the walls once closed constituting a confinement chamber inside of which the P pockets or pockets are present. The operating cycle of such a slaughter module 1 is as follows: during a first step, the flexible bag (s) P are introduced into the tank via one of the moving walls, in order to be positioned within the tank;

 the low-pressure pump 121 is actuated to fill the tank, in a second stage, with the water of the tank 120, then a high-pressure pump is actuated to reach the predetermined high pressures of up to 800 MPa, a third step that can be conducted for a period of about 1 hour; - In a last step, a depressurization valve (not shown) is actuated so as to drop the pressure inside the tank and evacuate the water from it. More specifically, the hygienization step is carried out at least according to the following phases:

 - pressure rise from 0.1 MPa to 100 MPa in 15 s;

 pressure rise from 100 MPa to 500 MPa in 1 min and 15 s;

 pressure rise from 500 MPa to 600 MPa in 30 s;

 pressure rise to 700 MPa and maintenance of the pressure at 700 MPa for about 1 h.

 Where the flexible bags P can then be extracted from the tank of the slaughter module.

 As illustrated in FIG. 1, at the outlet of the slaughter module, and therefore at the end of the high pressure hygiene step according to the method according to the invention, the insect larvae are extracted from their flexible pouch during an unpacking step E12. The larvae are then treated with an E13 extraction step aimed at separating the lipidic, proteinic, solid and aqueous phases of the larvae 1. At the end of this extraction step, products are obtained which are valorized during a final stage. E14.

 According to a preferred embodiment of implementation of an entomoculture method according to the invention, it is operated with a breeding chamber as illustrated in Figures 3 to 5.

 As it appears, this breeding enclosure 2 comprises:

a drum 20 rotatably mounted about an axis A and intended to accommodate a mixture of ground organic matter and insect larvae; an external support 3 (Figures 7 and 8) and independent of the drum 20; an arm 4 supported by the outer support 3, the arm 4 being adapted and intended to extend inside the drum to perform a number of functions detailed below.

 According to a main characteristic of the arm, it carries means for controlling the temperature and / or humidity conditions inside the drum 20. Referring to FIG. 6, these control means comprise:

 air suction means 40, the arm 4 consisting of a tube whose open end, inside the enclosure, constitutes a suction mouth through which the air can be sucked through a pump at the other end of the arm; humidity suction means 41;

 air injection means 42;

 water spraying means 43.

 The water spraying means can be used to control the hygrometry inside the drum, and also be used to clean more easily or completely inside the drum once emptied of the mixture of material organic (in the form of digestate) and insect larvae.

 All of these means are arranged on a portion of the arm intended to extend inside the drum.

 In this same part of the arm (the one intended to extend inside the drum), the arm also carries:

 a temperature sensor 44;

 a humidity sensor 45;

 a device for capturing images, and more specifically a camera 46.

Of course, the volume of substrate added to the volume of the larvae present in the drum is provided such that the arm carrying all of the sensor means listed above does not come into contact with the mixture present in the drum.

 It should be noted that the air suction means provided by the arm may be sufficient to bring air into the drum.

Moreover, a series of deflectors 47 are arranged on either side of the arm to cause turbulence inside the tank, this in order to maximize the heat exchange and thus the lowering of the temperature and / or hydrometry inside the drum.

 The air suction means can be used as air injection means, obviously reversing the flow of air, which allows to possibly push the stale air from the inside of the drum to the air. outside the drum, this depending on the weather conditions outside the drum.

 In addition, the arm is supported by the outer support in height relative to the drum. The arm therefore extends so as to descend from the support to the inside of the drum. The arm is supported independently of the drum, which allows it to be brought into the vicinity of the drum, and then inserted into the drum only after the drum has been loaded with the mixture of organic material and insect larvae.

 As appears in FIGS. 3 to 5, the arm has two sections hinged together, namely:

 a terminal section 48 extending at least partially inside the drum;

 an outer section 49 extending outside the drum in the extension of the section of the terminal.

 These two sections are thus coupled via a hinge 480.

 According to the present embodiment, the arm has a third section 491 hingedly mounted to the opposite end of the outer arm 49 relative to the end arm 48, this via a second hinge 490.

 Thus, the arm is articulated around these two joints and can take different configurations and inclinations, this to follow the tilts of the drum as will be explained later.

 Furthermore, as shown in Figures 3 to 5, the drum 20 has an inner wall 200 provided with blades 201, provided to contribute to the mixture of organic matter and insect larvae. These blades are arranged and designed so that, depending on the direction of rotation of the drum, the blades contribute to the path of the bottom substrate of the tank forward, or vice versa.

In addition, the blades are of variable geometry so as to be adapted to the type of substrate and the filling rate. These blades are sufficient to allow the overturning and mixing of the substrate without tilting of the tank. The variable geometry of the blades is optional, since it may be necessary to vary the position of the stirring blades in order to effect the desired material movements.

 The inner wall 200 of the drum further carries, on the side of the opening 202 of the drum, a truncated worm 203 which allows, in the direction of rotation of the drum, to guide the substrate outwards for the purpose of emptying drum or guide the substrate inwardly to repel the substrate within the drum as needed depending on the fill rate and the stage of recovery of the substrate.

 Moreover, as shown in FIGS. 3 to 5, the drum is pivotally mounted on a frame 5. For this, the drum is carried by a pair of cradles 51 1 which each incorporates a motor intended to cooperate with a pair of rack 510 to rotate the drum. The two cradles each extend in an arc and are concentric with each other about an axis A which constitutes the axis of rotation of the drum.

 As seen in FIGS. 3 to 5, the cradles are themselves mounted on a frame carried by the frame, this frame taking the form of a cross-member articulated at its center around a pivot 60.

 In addition, the equipment has an actuating member 50, consisting of a telescopic jack according to the present embodiment, extending in an articulated manner between the frame on the one hand and the bottom 520 of the drum. According to this arrangement, the variation of the length of the telescopic jack will cause the tilting of the drum around the pivot of the spider. Thus, the actuating member is adapted to drive the drum between a substantially horizontal position as illustrated in Figures 3 to 5 at a position inclined relative to the horizontal, plus or minus 20 degrees upwards or down. By bringing the bottom of the drum down, the drum will be in a position in which the substrate tends to be brought towards the bottom of the drum, while bringing the bottom of the drum in the up position relative to the horizontal, the drum will occupy a position corresponding to a phase of unloading the substrate and larvae from the drum.

 As is clear from Figures 3 to 5, the frame is constituted by a movable carriage 51 carrying wheels 512.

It is noted that the drum, on the side of the opening through which the arm is introduced into the drum, can be provided with an opening / closing means hermetic, with pressure relief valve, to promote a better fermentation of the substrate inside the drum.

 According to the principle of the invention, the equipment for implementing the entomoculture method described above comprises a breeding chamber associated with an arm also described above, and also comprises an external support 3, independent of the drum of the invention. breeding enclosure, which supports the arm 4.

 According to the present embodiment, the external support 3 is itself carried, at its upper end, by rails 30, with the possibility of varying the position of the external support along the rails as it will be explained later.

 With reference to FIG. 8, a controlled mechanical ventilation block 7 (VMC) makes it possible to draw air into the chamber via the suction means 40 constituting the mouth (inside the chamber). enclosure) of the tube constituting the arm, the tube of the arm being placed in communication via the block 5 with a duct 70 exhaust air exhaust.

 The block 7 VMC is connected by cable to the humidity and temperature sensors 44 and to the cameras and detector of hot spots mounted on the arm 4. The control of the block 7 is also performed taking into account the data provided. by an outside temperature sensor 71.

 In addition, as shown in FIG. 8, the outer support 30 carries: a water pipe 31 (skirting the arm 4), allowing the flow of water to the water spraying means 43 mounted on the arm and present inside the breeding enclosure;

 a delivery pipe 32 (along the arm 4) of organic additives or ferments, intended to deliver these adjuvants into the breeding chamber in order to optimize the recovery process;

 a data transfer cable 33 such as hygrometry data (inside the enclosure and internal to the substrate), temperature data (inside the enclosure and substrate surface or hot spots of the substrate) ), visual control thanks to the camera 46

(for the control of the surface of the substrate and the inner skin of the tank).

Furthermore, with reference to FIG. 9, an entomoculture installation for implementing the method according to the invention may comprise a plurality housing module module 2, each comprising a drum 20, an external support 3 independent of the drum 20 and an arm 4 supported by the external support 3.

 As indicated above, the external supports are carried by rails 30 which indirectly support arms 4, with the possibility of varying the position of the supports (and therefore that of the arms) along the rails.

 In addition to the medium support function management valuation, the rails can also perform the function of supporting means of contribution to each farm, material to valorize.

 In addition, it is noted that the external supports and the arms carried by the external supports being independent of the drums (and therefore the speakers), it is possible to move the rearing enclosures (for example to drain, clean or to maintain) simply and quickly, leaving the corresponding arms and brackets in place.

 Furthermore, as shown in Figure 9, the breeding enclosures can be arranged along two rails 30, spaced apart to provide a passageway for a vehicle and / or personnel.

Claims

An entomoculture method using a step of feeding insect larvae with organic waste and a step of killing the insect larvae with a view to transforming them into a valuable product, characterized in that step d slaughter is carried out by subjecting the larvae to a gradual increase in pressure up to a hygienization step during which the pressure is between 300 MPa and 700 MPa. Entomoculture method according to claim 1, characterized in that the hygienization step is carried out according to at least the following phases: pressure increase from 0.1 MPa to 100 MPa in 15 s;  pressure rise from 100 MPa to 500 MPa in 1 min and 15 s;  pressure rise from 500 MPa to 600 MPa in 30 s;  pressure rise up to 700 MPa and maintenance of pressure at 700 MPa for about 1 hour. Entomoculture method according to one of claims 1 and 2, characterized in that the slaughtering step comprises a step of falling asleep at a pressure of 0.2 MPa for a duration of a few seconds. Entomoculture method according to any one of claims 1 to 3, characterized in that the sleep stage is followed by the slaughter stage at a pressure greater than or equal to 0.2 MPa for a period of time. about 1 minute. Entomoculture method according to any one of claims 1 to 4, characterized in that the slaughtering step is preceded by a step of bagging the larvae. Entomoculture method according to claim 5, characterized in that the bagging step is conducted under a partial vacuum of between 90% and 99.9%.