FR3102991A1 - Process for manufacturing a feed or feed supplement for farm animals - Google Patents

Abstract

Process for the preparation of a food or a food supplement in the form of modular stack objects allowing a controlled release of nutritive and / or physiologically active substances for monogastric animals, comprising a core with an aqueous phase with water-soluble active substances and a lipid phase with liposoluble active components, the aqueous phase being dispersed in the lipid phase, and a coating of the core, in which the cores are prepared from a double water-in-oil-in-water emulsion followed by filtration or decantation and in which a coating is then carried out. Figure 1

Description

Process for the manufacture of a food or food supplement for farmed animals

Field of invention

The subject of the invention is a process for the manufacture of a food or a food supplement for monogastric farm animals, in particular fish. In particular, the invention relates to food or food supplements allowing a controlled release of the active substances which they contain.

State of the art

It is well known to use physiologically active substances to supplement the food of farm animals to improve their sanitary conditions and accelerate their growth.

Such physiologically active substances can be proteins, lipids, carbohydrates, but also vitamins and any form of food supplementation targeting prebiotics, probiotics, amino acids, antioxidants, or other molecules (i.e. essential oils) for nutraceutical or therapeutic purposes. direct or indirect.

The diversity of conditions in which food is ingested and digested requires a response adapted to each species and each stage of maturity of the animals.

Aquaculture feeds on the market are often manufactured by processing and formulating several raw materials using a process called extrusion. This process imposes strong constraints in temperature (>140°C) and pressure (>25 bars) for several minutes, which degrades the nutritional qualities of the raw materials and therefore of the food in fine.

In addition, this process impacts and freezes the design of the feed: pellets. However, these pellets are not an optimal format to facilitate absorption by a fish (buoyancy, size, attractiveness, etc.) and the uncontrolled dislocation of the pellet after ingestion is not optimal for good digestive assimilation by the fish.

All this leads to a low effective conversion rate of the active substances of food and food supplements for the growth and health of farmed animals and in particular fish. This also translates into poor economic performance for the aquaculturist, who has to deal with longer growth cycles and with larger quantities of food at iso-cycle time, and also poorer quality fish, and consequently less valued on the market.

On the other hand, these phenomena have a direct impact on the environment since reduced food conversion rates lead to an increase in the release of undigested organic matter in addition to ammonia from the digestion of proteins. These discharges destroy the surrounding ecosystem (eutrophication) and increase the risks of infections and pathology on the farms by degrading the quality of the water. This leads to an increase in the use of phytosanitary products.

The interest therefore remains for foods or food supplements whose structures and manufacturing processes make it possible to offer a response adapted to each species and each stage of maturity of the animals.

And in particular, the need exists for food and food supplements which allow rapid release of active substances or nutrients but sequenced, that is to say in specific and identified areas of the digestive system of the target animal for better metabolize these nutrients.

Brief description of the invention

The invention relates to the following methods:

1. Process for the preparation of a food or a food supplement in the form of modular stacked objects allowing a controlled release of nutritive and/or physiologically active substances for monogastric animals, comprising a core with an aqueous phase with active substances water-soluble and a lipid phase with liposoluble active components, said aqueous phase being dispersed in said lipid phase, and a coating of the core, comprising the following steps:
(a) preparing said aqueous phase by dispersing said water-soluble active substances in water and adding gelling reagents;
(b) injecting said aqueous phase into an oil to obtain a first emulsion of aqueous particles in the process of gelling in the oil;
(c) leaving to stand or heating said first emulsion to complete the reactions of gelation of the aqueous beads and to obtain gelled aqueous beads dispersed in the oil;
(d) adding said first emulsion to a mixture of at least one oil and at least one liquid wax;
(e) introducing all of said first emulsion and of said mixture of at least one oil and at least one liquid wax into an aqueous solution with stirring to obtain a second emulsion, said second emulsion comprising gelled aqueous particles dispersed in a lipid matrix, said lipid matrix itself being in the form of particles dispersed in said aqueous solution;
(f) cooling said second emulsion to a temperature below the melting temperature of said at least one wax to stabilize said lipid particles by solidifying said at least one wax;
(g) obtaining said lipid particles, ie said cores, by filtration or decantation; And
(i) forming the coating of said cores by successive immersions in baths of cationic and anionic polysaccharides.

2. Preparation process according to object 1, in which after having obtained the first emulsion of water-in-oil particles in step (b), said first emulsion is subjected to high shear, preferably between 2 000 and 20,000 s-1, to reduce the size of the aqueous particles in the oil before the gelling of said particles of the aqueous phase (step (b').

3. Preparation process according to one of objects 1 and 2, comprising a final step of drying the products under a stream of air at a temperature below 50°C, preferably between 18 and 40°C.

4. Preparation process according to any one of the preceding objects, in which said at least one wax is a crystallizable wax with a melting temperature below 90 degrees Celsius and preferably below 65 degrees Celsius.

5. Process of preparation according to any one of the preceding objects, in which the said gelling reagents comprise an anionic polysaccharide such as an alginate, a calcium salt and pyrophosphate.

6. Preparation process according to item 5, in which the calcium salt is chosen from the group of calcium sulphate, carbonate and stearate.

7. Process of preparation according to any one of the preceding objects, in which all the aqueous solutions used comprise a controlled quantity of osmotic agent.

8. Preparation process according to object 7, in which said osmotic agent is chosen from the group of sugars, salts, water-soluble polymers preferably with a molecular mass of less than 150 kg/mole, and combinations thereof.

9. Preparation process according to any one of the preceding objects, in which, after having obtained said lipid particles in step (f) and before forming the coating in step (g), said lipid particles are dispersed in a protein phase (step (f')).

10. Preparation process according to any one of the preceding objects, in which, before injecting said first emulsion into a mixture of oils and liquid waxes, a precise dose is added to said mixture of oils and liquid waxes said fat-soluble active substances.

11. Preparation process according to one of the preceding objects, in which, before injecting said first emulsion into a mixture of at least one oil and at least one liquid wax, dispersing in said mixture at least an oil and at least one liquid wax an exfoliated clay phase in a lipid medium.

12. Preparation process according to object 11, in which the exfoliation of a clay phase in a lipid medium is carried out in the presence of a surfactant, said surfactant having the characteristic of having a cationic polar head.

13. Preparation process according to object 12, wherein said surfactant is lecithin.

This manufacturing process has the advantage of never bringing all of its constituents to a high temperature likely to degrade their properties.

Description of Figures

The invention is described below with the aid of Figures 1 to 14, given solely by way of illustration:

presents schematically in section and without respecting the respective dimensions a first product which is the subject of the invention;

schematically presents in section a second product which is the subject of the invention;

schematically presents in section a third product which is the subject of the invention;

schematically presents an embodiment of a coating of the core of a product which is the subject of the invention;

presents a diagram of a manufacturing process of the first product;

presents a diagram of the additional steps for the manufacture of the third product;

shows the size distribution of aqueous particles;

shows the size distribution of lipid particles;

presents the evolution of the iodine index measured during the aging in the open air of lipid particles;

presents an image of a lipid particle obtained with a scanning electron microscope;

presents a curve for monitoring the rheological behavior of a protein layer;

presents an example of protein particles obtained after gelation;

presents the conductimetric monitoring of metered additions of charged biopolymers to the water; And

presents the evolution of the conductivity of lipid particles as a function of dosed additions of charged biopolymers.

Detailed description of the invention

Figure 1 presents schematically and in section without any respect for the respective dimensions of each phase a first product that can be produced with a method according to one of the objects of the invention.

This first product 10 comprises a core 12, a protein phase 11 and a coating 14 of the whole of the core 12 and of the protein phase 11. The core 12 comprises an aqueous phase in the form of spherical (or irregular) gelled particles 16 dispersed in a lipid matrix 18. The protein phase 11 surrounds the core 12 and is surrounded by the coating 14.

A first element of this first product is that it contains a gelled aqueous phase containing water-soluble active substances, including nutrients in particular.

Advantageously, the size of the gelled particles is between 1 and 200 μm and preferably between 20 and 100 μm.

The gelation of the aqueous phase makes it possible to limit the leakage of nutrients and active substances outside the particles. It also allows stabilization of the size of the particles by limiting coalescences and thus increasing the specific surface of the aqueous phase and therefore accelerating the rate of release of the active substances it contains in the digestion phase.

According to a preferred embodiment, the aqueous phase comprises an anionic polysaccharide such as an alginate with a content of between 1 and 4% by weight relative to the weight of the aqueous phase.

The aqueous phase can advantageously be gelled by reaction of the anionic polysaccharide with reagents such as a calcium salt as well as pyrophosphate or delta-gluconolactone.

The calcium salt can be chosen from the group of calcium sulphate, carbonate and stearate.

The solubility of the calcium salt is obtained by reaction with protons (acids) released in situ. They can be generated by reagents such as pyrophosphates or deltagalactolactone in contact with water.

Advantageously, the aqueous phase also comprises an osmotic agent.

This osmotic agent can be chosen from the group of sugars, salts, water-soluble polymers preferably with a molecular mass of less than 150 kg/mole and combinations thereof.

A preferred choice of osmotic agent may be sorbitol with a content of less than 5% by weight relative to the weight of the aqueous solution so as not to make the final product indigestible. A content between 0.8 and 1.5% by weight of sorbitol is optimal. You can also advantageously use Guérande salt which also provides useful mineral salts.

Preferably, the content of the aqueous phase dispersed in the lipid matrix is between 10 and 50% by volume, and preferably between 15 and 30% by volume relative to the total volume of the aqueous phase and of the lipid matrix.

Below 10% by volume, the volume of the aqueous phase is no longer sufficient to easily introduce the water-soluble active substances and to have a good homogeneity of composition of the cores of the objects.

Beyond 50%, it becomes much more difficult to maintain a water emulsion dispersed in the lipid phase.

The gelled aqueous phase may comprise hydrophilic active substances such as amino acids, vitamins, prebiotics, probiotics, antioxidants, and combinations thereof.

A second element of this first product 10 is that the aqueous phase 16 is dispersed in a matrix or lipid phase 18.

Advantageously, the lipid matrix 18 comprises at least one vegetable or animal oil, in particular fish, and at least one crystallizable wax. Waxes can be of animal (beeswax) or vegetable origin.

Preferably, the waxes used are crystallizable waxes with a melting point below 90 degrees Celsius and very preferably below 65 degrees Celsius.

The level of waxes is advantageously between 5 and 25% by weight relative to the weight of the whole of the lipid matrix, and very advantageously between 10 and 20%.

According to preferred embodiments, the lipid matrix is substantially spherical in shape and thus the core is substantially spherical in shape and has a diameter of between 10 and 1000 μm and preferably between 200 and 400 μm.

The lipid matrix can advantageously comprise vitamins.

Preferably, this lipid matrix comprises a high content of omega 6 and omega 3, in particular of the DHA and EPA types.

The lipid matrix advantageously comprises at least 1% by weight of omega 3 of DHA and EPA types relative to the weight of the lipid matrix. It also preferably comprises less than 30% by weight of omega 3 of the DHA and EPA types and very preferably less than 10% by weight relative to the weight of the lipid matrix.

According to an advantageous embodiment, the lipid phase comprises a mineral filler.

The mineral filler is advantageously chosen from the group of phyllosilicates, such as clays, talcs and micas.

Preferably, the phyllosilicate is a smectite. Smectites have the advantage, due to their lamellar structure with a greater spacing between the lamellae than other phyllosilicates, of being able to be swollen by small hydrophobic molecules which will exfoliate the clay platelets and thus facilitate their dispersion in the lipid matrix. Micas and talcs can also be exfoliated in this way, but the energy that would be required to disperse the lamellar layers in the lipid matrix would be much higher.

According to an advantageous embodiment, the content of the mineral filler in the lipid matrix is between 0.5 and 35% by weight and preferably less than 15% by weight relative to the weight of the lipid matrix.

The presence of this mineral filler in the lipid matrix has several important advantages. First of all, the load allows to control the buoyancy of the objects when they are used in aquaculture. It also strengthens the resistance of objects to the action of oxygen by greatly reducing its diffusion kinetics in the core of objects and acts as a barrier to limit the escape of small molecules of nutrients and active substances. Finally, the very large developed surface of the smectite sheets makes it possible to microstructure the lipid matrix on a nanometric scale, which makes it possible to compartmentalize and play on the kinetics of digestibility of the lipid matrix.

The third element of this first product 10 is a gelled protein phase 11 surrounding the lipid matrix 18, and thus surrounding the core 12. This protein phase comprises proteins. This phase is advantageously prepared from proteins dissolved in a gelled aqueous phase.

The presence of this protein phase has the advantage of providing the target animal, in addition to the active substances, with the amino acids necessary for its growth, and of promoting the attractiveness of the food.

The protein phase 11 as shown in Figure 1 surrounds a single core 12 with a substantially spherical geometry. However, depending on the method used to disperse the nuclei 12 in the protein phase 11, the same object 10 may comprise several nuclei 12 dispersed in the protein phase 11. Consequently, the external geometry of the objects and of this protein phase is very variable. (see figure 12).

Preferably, the protein phase comprises negatively charged and gellable polysaccharides, such as alginates, pectin, xanthan, gellan gum, etc.

Negatively charged polysaccharides can be functionalized with a carboxylic, sulfonate, alkoxide or phosphate function, alone or combined with positive charges (such as hyaluronic acid). The physico-chemical conditions will be adjusted so as to have an excess of negative charges favoring the gelling conditions.

Advantageously, the gelled protein phase is cross-linked by the action of a gelling agent released with a delay time which may be a metal which can complex with the carboxylic functions of the polysaccharides or an inorganic or organic oligomer with a charge opposite to the charge of the polysaccharide. target.

The modulation of the cross-linking delay time between 15 min and several hours makes it possible to promote mass mixing of the ingredients without caking of the gel, and thus to shape the food or food supplement.

The gelling agent may comprise calcium, zinc, magnesium or transition metal cations and a source of acidic protons (such as pyrophosphate or deltagluconolactone) which can be hydrolyzed in water, allowing the release of the ionic form.

Preferably, the gelled protein phase comprises a gellable polysaccharide content of between 0.5 and 4.5% by weight and preferably less than 2% by weight relative to the weight of the gelled protein phase during the preparation of this protein phase. , i.e. before the final drying phase of the product.

At 5% alginate in a food ration, the literature describes a deterioration in the efficiency of digestion because the polysaccharides trap nutrients. Beyond 5% polysaccharides play a laxative role by trapping more water and the associated nutrients.

Preferably, the gelled protein phase comprises a protein content of less than 30% by weight relative to the weight of the gelled protein phase during the preparation of this protein phase. Beyond the gelation of the protein phase becomes difficult, because the proteins block the reactive sites of the polysaccharides.

Advantageously, the proteins of the protein phase comprise proteins of size less than 30 kDa. The digestion of these proteins can thus be done more quickly, because there are fewer bonds to be cut to bring the peptide fragments to a size that can be assimilated by the digestive tract.

Advantageously, the content of the protein phase in all the finished products is between 5 and 75% by weight relative to the total weight of the whole.

According to an advantageous embodiment, the protein phase also comprises a dispersed mineral filler, such as silica, phyllosilicates, metal oxides, etc.

This mineral filler, for example clay, has the advantage of allowing the buoyancy of objects to be modulated. It also constitutes a barrier which opposes the diffusion in objects of oxygen. Indeed, the very large developed surface of the smectite sheets makes it possible to microstructure the protein matrix at the nanometric scale, which makes it possible to compartmentalize and play on the kinetics of digestibility of the protein matrix. Microstructure obtained by the interactions between the layers of clay charged positively on the sides and negatively on the larger surface with the alginate or the proteins of the protein phase.

Advantageously, the mineral filler is a phyllosilicate and very advantageously a smectite.

Advantageously, the protein phase comprises an osmotic agent.

This osmotic agent can be chosen from the group of sugars, salts, water-soluble polymers preferably with a molecular weight of less than 150 kg/mol, and combinations thereof.

A preferred choice may be sorbitol with a content of less than 5% by weight relative to the weight of the aqueous solution so as not to make the final product indigestible. A content between 0.8 and 1.5% by weight of sorbitol is optimal. You can also advantageously use Guérande salt which also provides useful mineral salts.

According to another advantageous characteristic, the whole of the protein phase 11 and of the core 12 is of any shape with a largest dimension comprised between 500 μm and 5 mm (see FIG. 12).

The size of the objects according to the invention can easily be adapted to the intended target, to be compatible with the supply capacities of the latter.

The invention also relates to a food with a total protein content of between 20 and 70% by weight relative to the weight of the entire finished product. This content is obtained after the last optional step of drying the product. Proteins are mainly provided by the protein phase. In particular, from 80% to 100% by weight, advantageously from 90% to 100% by weight, of the proteins of the food are provided by the protein phase.

Another subject of the invention is a food supplement with a total protein content of between 10 and 20% by weight relative to the weight of the entire finished product. This content is obtained after the last optional step of drying the product. Proteins are mainly provided by the protein phase. In particular, from 80% to 100% by weight, advantageously from 90% to 100% by weight, of the proteins of the food supplement are provided by the protein phase.

The proteins of the protein phase are predigested, at least in part, in the stomach of the animal, but the gelation of this protein phase coupled with the coating constitutes a physical barrier to the release of these predigested proteins in the stomach. It is interesting to limit such a release of predigested proteins in the stomach because their metabolization in the stomach would serve to create digestion and motor energy by causing ammonia-type rejections resulting from this catabolization, instead of being metabolized in the intestines of animals, where their absorption is most efficient for the growth of these animals.

The fourth element of this first product 10 is to include a coating 14 around the protein phase 11.

This coating may comprise n layers of biocompatible materials, in particular biopolymers, with an alternating stack of positive and negative electrostatic charges which form coacervates structured as a stack of layers, and n is at least equal to 1.

This coating system has the advantage of facilitating the modulation of the thickness of the coating layer and the wide choice of biopolymers makes it possible to modulate the mesh of biopolymers on the surface, which will then be stiffened by more or less reticulations. strengths of this mesh.

n is an integer. n is advantageously less than or equal to 15 and preferably between 2 and 10.

This variable number of layers is adapted to obtain a good compromise between encapsulation quality and controlled release in the digestive tract while allowing easy implementation.

The outer layer of this coating is preferably made of a positively charged polymer because this has antibacterial properties and thus improves the preservation of the food or food supplement.

Advantageously, the biocompatible materials are charged biopolymers.

The biopolymers of the coating can be chosen from the group of positively charged polysaccharides, such as polypeptides, chitosan, chitin derivatives, gums used as amine functionalized texturizing agent such as functionalized guar gum, their combinations and negatively charged polysaccharides such as polypeptides, pectin, gum arabic, xanthan, alginates, carrageenans, cellulosic derivatives, etc., as well as their combinations.

Advantageously, the coating comprises crosslinking agents, in particular by metal complexation or chemical bridging which can be chosen from the group of charged transition metals and multicharged anions such as polyphosphates including trisodium tetraphosphate (TSTP) Na3P4O10.

Advantageously, the core and/or the protein phase comprises(s) a charged polymer, or proteins with surface charges or cationic, anionic or zwitterionic surfactants.

It is also possible to specifically add charged biopolymers to the core and/or the protein phase to generate these charges. They will be chosen from anionic or cationic biopolymers mentioned above, but can also combine fillers as in hyaluronic acid.

This makes it possible to modulate the residual or free charges by adjusting the pH conditions of the medium or by adjusting the stoichiometric balance of the complexation systems in the protein phase.

The physico-chemical system is thus adjusted so as to obtain an excess of free amines from the proteins of the protein phase which will be positively charged under conditions of pH below 9. This excess of positive charges is the necessary condition for depositing the first layer of anionic biopolymer of the coating.

If necessary, if the physico-chemical system of the protein layer rather presents an excess of negative charges, linked to the balance of the ingredients which constitute it, the coating will begin with a first layer of cationic biopolymers.

The coating of the protein phase and of the core can also comprise a layer of reinforcing materials.

These reinforcing materials can be chosen from the group of clays, silicas and filled fibers, and their combinations

These reinforcing materials have a predominance of negative electrostatic charges on their surfaces and are thus attracted by the positive surface charges of the coating. It is thus possible to place a reinforcement layer between two layers of cationic polysaccharides.

Preferably, the reinforcing materials are a phyllosilicate and very preferably a smectite.

This coating 14 therefore consists of layers of biopolymers, advantageously of polysaccharides, loaded alternately more and less. In the stomach of the animal, the pH is acidic and it is the mesh of the positively charged biopolymers which is the most resistant to this acidic pH and which ensures the integrity of the coating.

The negatively charged layers of the coating are advantageously bridged by cations such as Ca++. These bridges are dissolved in an acid medium, so when we arrive in a neutral to basic medium (the intestines) we have a real release of all the layers of the coating. As soon as there is a breach in the coating, the enzymes of the bile will be able to penetrate to the nucleus and lead to the release of the lipids as well as their nutrients and active substances, leading very quickly also to the release of the particles of the aqueous phase and their nutrients and active substances. This coating therefore ensures the rapid release of all nutrients and active substances in the area of the intestines of monogastric animals, where their absorption during their journey is most effective.

This product is designed to provide nutritional balance in growing animals, which must cope with pathogens and the stress of the breeding environment. Thus this product is recommended, in the form of food or food supplement in the juvenile stage of monogastric species with significant mortality: such as in avian breeding for example for chicks, or in aquaculture for fry. The flexibility of formulation and modulation of properties, also makes it an interesting product to accompany the finishing of pre-commercial animals.

FIG. 2 presents a second product 20 that can be produced with the method according to one of the objects of the invention. This second product 20 is similar to the first product 10 but has a simplified structure: it does not include a protein phase between the core 12 and the coating 14. Like the product 10, it comprises a core 12 comprising an aqueous phase composed of aqueous particles 16 dispersed in a lipid matrix 18 and a coating 14.

This second product is particularly interesting for supplying specific nutrients or active substances.

Figure 3 shows a third product 30 similar to the first product 10 of Figure 1.

This third product 30 further comprises, compared to the first product 10, a coating or coating 34 of the lipid matrix 18 disposed between this lipid matrix 18 and the protein phase 11.

Like the coating 14 of the product 10, this coating 34 comprises n layers of biocompatible materials, with an alternating stack of positive and negative electrostatic charges forming coacervates structured in a stack of layers, n being at least equal to 1. Preferably, the number of layers n is between 2 and 10. n is an integer. The biocompatible materials are as previously described for coating 14.

This addition of the coating 34 makes it possible, if necessary, to delay the release of the active components from the internal phase of the core. The outer layer of this coating 34 is preferably made of a positively charged polymer because this has antibacterial properties and thus improves the preservation of the food or food supplement.

This third architecture makes it possible to meet even later release requirements in the digestive tract of the nucleus, such as the release of prebiotics or probiotics which must remain intact until the terminal phase of the digestive tract.

Figure 5 shows the different steps of a method of manufacturing the first product 10 according to one of the objects of the invention.

The core or cores of the first product 10 are prepared from a water-in-oil-in-water double emulsion followed by filtration or decantation. Then this core is completed by a protein phase which will be shaped to the target size and geometry. A coating 14 is then carried out. The last, optional step of preparing the products is drying to bring the moisture content of the products to a value of less than 10% by weight, relative to the total weight of the product. This drying is carried out at low temperature, preferably below 50°C, for example between 18°C and 40°C.

Step (a) consists of preparing an aqueous phase by dispersing the necessary water-soluble active substances in water and adding the gelling reagents. These reagents are as described previously for the gelled aqueous phase, and can be a polysaccharide, a calcium salt, in particular calcium sulphate or calcium carbonate, in the presence of pyrophosphate or delta-gluconolactone.

Step (a') consists in preparing a gelled protein phase by dispersing proteins in water with gelling reagents, optionally an osmotic agent and optionally mineral fillers such as phyllosilicates.

in step (b), the aqueous phase resulting from step (a) is injected into a vegetable or animal oil to obtain a first emulsion of aqueous particles in oil.

Then, in step (c), this first emulsion is allowed to stand or moderately heated, at less than 100° C. and ideally at less than 60° C., for example from 40° C. to 60° C., to complete the gelling reactions of aqueous particles and obtaining robust gelled aqueous particles dispersed in oil (step (c)).

The first emulsion from step (c) is then added to a mixture of at least one animal or vegetable oil and at least one liquid wax prepared beforehand. The oil+wax mixture advantageously comprises from 1 to 50% by weight of wax relative to the total weight of the mixture, more advantageously from 5 to 15% by weight of wax. For the crystallizable wax(es) used to be liquid, the temperature of the mixture is higher than the melting point of the waxes (step (d)).

In step (e), all of the first emulsion and the mixture of at least one oil and at least one liquid wax, resulting from step (c), are introduced into an aqueous solution with stirring to obtain a second emulsion; this second emulsion comprises the gelled aqueous particles of the first emulsion dispersed in a lipid matrix which is itself in the form of particles dispersed in the aqueous solution.

This second emulsion resulting from step (e) is cooled in step (f) to a temperature below the solidification temperature of the crystallizable waxes present in order to stabilize the lipid particles.

It remains in step (g) to isolate the lipid nuclei or particles of the products by filtration or decantation by eliminating the aqueous phase.

After step (g), the lipid particles resulting from step (g) are dispersed in the protein phase in the process of gelling prepared in step (a′). The homogenization is done with the minimum of shear, the shear obtained for example by stirring by hand (step (h)). The dispersion is then, for example, introduced into a cold extruder to shape the product through a die. at the exit of the die, the extrudate is continuously cut with a rotating blade to the target size and assemblies consisting of cores coated with a protein phase ready to be coated are obtained.

This addition of the protein phase can also be carried out in a fluidized bed or in spheronization.

The processes chosen, extrusion, fluidized bed, spheronization, are implemented at low temperature, below 50°C (step (h)), for example ranging from 18°C to 50°C.

Note: the gelation kinetics of the protein phase are adjusted to allow all the operations of step (h) to be carried out. The gelation is completed at the end of step (h) only after a rest time allowing the solidification of the layer.

It should be noted that due to their mode of manufacture by preparation of emulsions, the aqueous phases 16 and the lipid particles 18 have a relatively spherical geometry. On the other hand, the assemblies consisting of the protein phase 11 surrounding the lipid phase 18 of the products 20 which are obtained by cutting an extrudate from a die can take any shape.

Finally, in step (i) the coating of the assemblies consisting of the protein phase 11 surrounding the lipid phase 18 resulting from step (h) is formed by immersion in an aqueous bath in which solutions of materials cationic and anionic biocompatible.

After the coating of step (i), the products are advantageously dried by flow of air at low temperature below 50°C and preferably between 18 and 40°C to bring the humidity level to a lower value. 10% by weight, relative to the total weight of the product. This increases the shelf life of the products. This last step (j) is optional.

FIG. 4 illustrates this formation of the coating of the assemblies consisting of the protein phase 11 surrounding the lipid phase 18 resulting from step (g) by successive additions of biopolymers, advantageously polysaccharides, positively and negatively charged.

Note: The depiction of the protein phase in Figure 4 has been modified from that of the other figures for clarity.

Note: the set is here schematized in the form of a particle but it can have any shape

On the left of Figure 4, we see the assembly consisting of a core 12 of the first product 10 surrounded by a protein phase 11. This protein layer comprises free surface charges, preferably positive.

This assembly is coated by adding an aqueous solution of negatively charged biopolymers 52, for example polysaccharides.

By electrostatic interactions, the negatively charged biopolymer will cover the surface of the assembly to form a negative layer of coacervate.

An aqueous solution of positively charged biopolymer 54 is then added to the dispersion with the particles now negatively charged at the surface. This will then spontaneously cover the layer previously placed.

The operation is repeated by alternating the aqueous solutions of more and less charged biopolymers until a coating 14 comprising the desired number n of layers is obtained. Usually n is between 2 and 10.

Advantageously, in step (e), the continuous aqueous solution in which the second emulsion is produced (emulsion of lipids with wax) comprises at least one osmotic agent and at least one surfactant.

The osmotic agent can be chosen from the group of sugars, salts, water-soluble polymers preferably with a molecular weight of less than 150 kg/mole, and combinations thereof.

A preferred choice may be sorbitol with a content of less than 5% by weight relative to the weight of the continuous aqueous solution so as not to make the final product indigestible. A content between 0.8 and 1.5% by weight of sorbitol is optimal. You can also advantageously use Guérande salt which also provides useful mineral salts.

The presence of an osmotic agent has the advantage of setting up an osmotic barrier which prevents the passage of the active substances present in the aqueous phase of the first emulsion which also contains an osmotic agent, of the same nature or different from that of the external continuous phase, advantageously from those previously described; this internal aqueous phase being itself dispersed in the lipid phase. The osmotic agent makes it possible to guarantee a balance of osmotic pressures. This avoids a pumping effect of nutrients through the lipid wall.

The protein phase 11 also comprises an osmotic agent, of the same nature or different from that of the external continuous phase, advantageously from among those described above. This reinforces the effectiveness of the osmotic barrier.

Very advantageously, the surfactant is chosen from the group of phospholipids, polymers such as carboxymethylcellulose (CMC), hyaluronic acid, polylysines, proteins such as casein or hydrolysates of vegetable or animal proteins, surfactants, and their combinations.

FIG. 5 also presents an additional and optional step (a'') in which a dispersion of a mineral phase such as clays is carried out in at least part of the mixture of at least one oil and at least one liquid wax animal or vegetable oils and liquid waxes used in step (d). As previously indicated, these clays are preferably phyllosilicates and very preferably smectites.

To facilitate the exfoliation of the clay sheets in this lipid medium, the dispersion is carried out in the presence of a surfactant, which preferably has a cationic polar head.

One can advantageously use lecithin, betaine, polylisine, as well as their combinations.

FIG. 5 also presents another additional and optional step (c′) in which, after having obtained the first emulsion of aqueous particles in oil (step (b)), it is subjected to high shear such as rotor/stator to homogenize and reduce the size of these aqueous particles before their complete gelation. This shear is preferably between 2,000 and 20,000 s-1.

The manufacture of the second product 20 is similar to that of product 10, it suffices to carry out a coating directly after having obtained the lipid particles in step (g).

Figure 6 shows the additional steps for the preparation of the third product.

After step (g) which makes it possible to obtain the lipid particles 18 by filtration or decantation, a coating 34 of these lipid particles 18 is formed by successive additions of solutions of biopolymers, advantageously of polysaccharides, positively and negatively charged (step ( g')). The last addition is preferably that of a positively charged biopolymer.

Then, the coated lipid particles thus obtained following step (g′) are dispersed in a protein phase, and the assembly is shaped by cold extrusion. The addition of particles in the protein phase can also be done by deposition in a fluidized bed or by spheronization. Cylinders or geometries (depending on the die used) of protein phase in which the lipid particles are dispersed are obtained. It is then necessary to cut, for example with a rotating blade, these extrudates to obtain the sets of cores 32 coated with the coating 34 dispersed in a protein phase 11 of the third products (step (h)).

It remains to carry out the coating 14 to obtain these third products 30. This coating is carried out as previously described.

A last optional drying step can then be carried out as previously described under an air flow at low temperature, preferably below 50°C, for example between 18 and 40°C, until a lower humidity level is achieved. 10% by weight, relative to the total weight of the product.

Preparation of a dietary supplement

An example of the preparation of a food supplement of the first product is now described.

Preparation of the gelled internal aqueous phase

This preparation includes the following steps:

Fill a beaker with water. Then the hydrophilic nutrients to be encapsulated are added. These nutrient contributions represent about 30% by weight compared to the weight of the water put in the beaker. The solution is then mixed in a high shear rotor-stator mixer of the Silverson Mixer type, L5M-A for 1 min at 1000 rpm (revolutions per minute). Then, 3.5% by weight of sodium alginate is added to the previous solution. Mix with the high shear mixer for 5 min at 2000 rpm. After complete dispersion of the alginate above, simultaneously add 0.5% by weight of pyrophosphate and 1.75% by weight of calcium sulphate. The mixture is quickly homogenized with a rotor-stator mixer at 2000 rpm, then the entire aqueous phase is poured into a volume of cod liver oil serving as a dispersion medium. The ratio of the volume of oil to the volume of the aqueous phase is less than 3.4. The whole is mixed vigorously with the high-shear mixer at 2000 rpm to reduce the size of the water drops in the oil before the gelling of the aqueous phase. The mixture is allowed to stand for 15 min so that the particles of aqueous phase solidify.

Figure 7 shows the size distribution of the gelled aqueous particles obtained. The average size of the particles of aqueous phase obtained with the shear rate at 2000 rpm is 161 μm. The average size can be reduced by increasing the shear rate of the solution, or by changing the viscosity of the alginate solution. By decreasing the concentration of alginate in the solution from 3.5% by weight to 2% by weight, a reduction in viscosity of more than a factor of 10 was obtained. The shearing is then more effective and the average size of the particles decreases.

Preparation of the crystallizable lipid phase

Preparation of a first beaker of molten wax

In a first beaker, a given mass of beeswax or sodium stearate is added, and a mass of sunflower oil 15% greater than the mass of beeswax or sodium stearate. The sum of the two ingredients represents 25.5% by weight of the total mass of the lipid phase prepared. Then the first beaker is placed in a water bath preheated to 75°C until the wax has completely melted (wax melting temperature of 60 to 63°C).

Preparation of a second beaker of exfoliated clay in oil

In a second beaker, 100 weight units of rapeseed oil, 30 weight units of linseed oil, 1.24 weight units of betaine citrate, 1.24 weight units of soybean lecithin, 50 weight units of weight of montmorillonite pre-impregnated with 10% by weight of water relative to the weight of the montmorillonite. The whole is mixed with the high shear mixer for 30 min at 2000 rpm. The mixture is completed with specific contributions such as vitamins A, E, D, K etc… for less than 0.2 weight units. The exfoliated clay preparation represents around 30% by weight relative to the total mass of the lipid phase prepared. The quality of the exfoliation of montmorillonite in oil can be assessed by optical microscopy by observing the homogeneity of the dispersion, with the reduction of macroscopic aggregates of several hundred µm.

Pooling of the prepared lipid phases in a third beaker

In a third beaker, kept in a water bath at 70°C, the prepared oil phases are combined, according to the following proportions:

44% by weight of the dispersion of gelled aqueous particles in a previously prepared cod liver oil lipid matrix;

31% by weight of the mixture from the second beaker (rapeseed and linseed oils, exfoliated montmorillonite, etc.); And

25% by weight of the mixture of liquid waxes and sunflower oil prepared previously.

Homogenize with a high shear mixer for 2 min at 1000 rpm. An oil phase is obtained ready to be dispersed to form the enriched lipid particles.

Preparation of the external aqueous phase

In a jacketed reactor, equipped with a stirrer and temperature control, an aqueous solution is prepared according to the following composition:

water for a volume equivalent to 2.5 times the volume of lipid phase to be dispersed;

1% by weight relative to the mass of the aqueous solution of osmotic agent (sorbitol or sodium chloride); And

0.4% by weight relative to the mass of the aqueous solution of casein (surfactant, which can be substituted by animal or vegetable proteins).

It is homogenized until the perfect solubilization of the ingredients, and the solution is brought to 65°C.

Manufacture of lipid particles

With a stirrer suitable for dispersing solids, the continuous aqueous phase is stirred at 450 rpm while maintaining the temperature at 65°C. Then, all of the lipid phase prepared above and maintained at 70° C. is quickly poured into the external aqueous phase. The dispersion is allowed to stabilize until it reaches approximately 62° C., the stirring is reduced to 400 rpm, the mixture is cooled with the jacket of the reactor to reach 60° C., the stirring is reduced to 350 rpm, the cooling by adding ice-cold water to quickly reach 45° C., the lipid particles are allowed to cool to room temperature via the jacket of the reactor while maintaining stirring at 150 rpm. When the dispersion is at less than 25° C., the solidified lipid particles are filtered through a sieve.

The lipid particles thus obtained are characterized in size using the Malvern Mastersizer 3000 particle size analyzer with liquid dispersion by hydro EV, with the software of the size determination device (Fraunhöfer equation). The measurements were carried out on 3 manufacturing trials: the three trials give the same average size of the lipid particles of 330 μm (Figure 8).

Figure 9 shows the evolution of the iodine index measured according to standard NF EN ISO 3961 (September 2013), during the aging in the open air of the lipid particles. Line L1 gives the reference iodine number obtained from the formulation of the particles. Lines L2 and L3 give the upper and lower 95% confidence limits and line L4 the evolution of the measured iodine index of the lipid particles. This line L4 shows that all the measurements after the first are within the interval between the upper and lower confidence limits and this makes it possible to confirm the storage stability of the particles thanks in particular to the increase in the average path of the particles. oxygen molecules imposed by the presence of clay. Thus, during storage, no significant variation is observed in the number of unsaturations (double bonds from omega 3-6 and 9) provided by the oils used for the formulation.

Figure 10 presents an image of a lipid particle obtained under a scanning electron microscope.

Outer protein layer – preparation of the protein layer covering the lipid particles

Preparation of the protein matrix containing the lipid particles:

In a kneading-type planetary mixer, we introduce:

100 parts by weight of the protein formulation corresponding to the nutritional requirements of the target species;

33 parts by weight sodium alginate;

8.3 parts by weight pyrophosphate;

33 parts by weight calcium sulfate;

1 part by weight sorbitol (osmotic agent)

nutritional additives according to the nutritional target (quantity less than 2 parts by weight).

After homogenization of the solids, a volume of water whose mass corresponds to 600 parts by weight is added and the mixture is vigorously homogenized with a kneading-type planetary mixer for 10 min.

A mass of lipid particles corresponding to 630 parts by weight is introduced. Note: The residual moisture of the lipid particles must be taken into account, which can vary from 2 to 50% by weight. Then homogenize by limiting the shear until a homogeneous paste is obtained. This paste is then introduced into a single-screw cold extruder to shape the paste through a die with a target diameter of the size of the food supplement. The extrudate is continuously cut by a rotating blade to the target size of the dietary supplement.

The protein particles are allowed to stand for two hours to obtain their solidification.

The food solidification kinetics were characterized using the ARES-G2 rheometer from TA-instrument, with the 40 mm² cone/plane mobile. A rotational shear of 5° was applied at a frequency of 1 Hz, and the evolution of the force over time was measured.

Figure 11 shows a monitoring curve of the rheological behavior of the protein layer in the case of a protein phase obtained with 2% by weight of alginate and 15% by weight of protein relative to the total weight of the protein phase. This figure 11 gives the evolution as a function of time of the modules G' and G'' measured.

At short observation times, a destructuring of the polyelectrolyte/protein gel is observed, with a decrease in the shear force G', marking several stages. Then a resumption of the force beyond 3800 seconds reflecting the emergence of a domain of percolating reticulation between the two shear plates. This cross-linking seems to saturate at 8300 seconds, then there is a drop, probably linked to the separation of the solidified sample from the wall of the cone/plane.

We deduce that the mixture can be worked for about an hour without risking destroying the gelation mechanism, and with two consecutive hours of rest we reach the maximum level of rigidity of the food supplement. The protein particles thus obtained can be stored cool (4°C), or used for the coating step by depositing a layer of biopolymer layer-by-layer, in English "Layer by Layer".

Figure 12 shows an example of protein particles obtained after gelation with a size of the order of a millimeter.

Preparation of the release modulation coating by a biopolymer deposited layer by layer (in English "layer by layer")

Coating layer by layer

The procedure is described for 100 g of lipid particles dispersed in 300 g of water supplemented with 1% sorbitol.

A stirring wheel is used which promotes good homogenization, without inducing excessive shearing of the solution (double-bladed wheel).

We prepare :

2000 ml of a first aqueous solution of chitosan at 0.1% by weight relative to the weight of the aqueous solution (with 0.05% by weight of acetic acid);

2000 ml of a second aqueous solution of sodium alginate at 0.1% by weight;

200 ml of a third aqueous solution of calcium chloride at 2% by weight; And

200 ml of a fourth aqueous solution of trisodium tetraphosphate (TSTP) at 0.5% by weight.

Start the additions with the 0.1% by weight sodium alginate solution; the mixture is stirred for 1 to 2 min between each addition. Then add the chitosan solution.

The procedure followed and the proportions of each addition are as follows (all % are % by weight):

+ 20 ml of 0.1% sodium alginate solution;

+ 20 ml of 0.1% chitosan solution;

+ 60 ml of 0.1% sodium alginate solution;

+ 20 ml of 0.5% trisodium tetraphosphate (TSTP) solution;

+10ml 0.1% chitosan solution;

+ 10 ml of 2% calcium chloride solution;

+ 4.25g Montmorillonite;

+ 100 ml of 0.1% chitosan solution;

+ 80 ml of 0.1% sodium alginate solution;

+ 20 ml of 0.1% chitosan solution; And

+ 20 ml of 2% calcium chloride solution.

The mixture is stirred for 15 min at 370 rpm. This procedure makes it possible to obtain a coating with seven layers, the first of which is an anionic sodium alginate and the last of cationic chitosan. In the middle of the coating, there is a layer of sheets of smectite (montmorillonite). These operations could be repeated up to seven times in the laboratory.

Characterizations:

The lipid particles remain dispersed in solution, the non-flocculation can be followed with the naked eye as charged biopolymers are added.

The conductimetric monitoring of the conductance of the solutions makes it possible to monitor the deposition of charged biopolymers.

As a reference, we measure the evolution of the conductivity of a pure water solution, to which we make metered additions of 0.1% chitosan solution (curve C1), then independently metered additions of 0.1% sodium alginate (curve C2), and finally the combination of the two (curve C3). Figure 13 shows the results obtained.

We thus characterize the increase in the conductivity of the solution during the addition of chitosan and sodium alginate, with a greater conductivity for the alginate. The combination of the two reagents results in a less rapid sawtooth increase in the conductivity compared to that of the anionic and cationic polymers alone, because the charges largely neutralize each other, and the radius of gyration of the coacervates becomes greater (conductivity apparently lower).

Figure 14 shows the evolution of the conductivity of a solution of lipid particles during metered additions of charged biopolymers. This figure 14 shows that the addition of anionic and cationic biopolymers does not induce an increase in the conductivity of the solution, on the contrary, it decreases. This is the signature of the condensation of anionic and cationic biopolymers on the surface of the particles, leading to the reduction of the overall conductivity of the solution, because the large lipid particles contribute little to the conductivity, and the salts in solution (agent osmotic) are trapped in the interface during condensation, and no longer contribute to the conductivity of the solution.

The foods and food supplements which constitute some of the objects of the invention are therefore products with a modular architecture which make it possible to encapsulate various nutrients and active substances and to release them into the digestive system of the target animals.

Stabilization thanks to the materials of the coating allows it to resist the acid medium of the stomach while allowing rapid disintegration in a subsequent basic medium, which ensures a very rapid and effective release of all the nutrients and active substances where they are the most effective.

The modular architecture of the core makes it possible to incorporate into the internal aqueous phase around twenty different water-soluble active substances. In the first product, this incorporation takes place in particles with a diameter of around 20 to 100 µm; in the internal lipid phase, it is also possible to incorporate about twenty different liposoluble active substances in a matrix with a diameter of about 400 μm or less.

The manufacturing process is also very respectful of these nutrients and active substances.

The products which are the subject of the invention are thus, with their modular architecture, very flexible in use and by varying the manufacturing conditions, it is possible to vary the respective dimensions of the particles and of the nuclei as well as the nature and the quantity of the active substances and nutrients to fine tune them to all target animals.

Claims (13)

Process for the preparation of a food or a food supplement (10, 20, 30) in the form of modular stacked objects allowing controlled release of nutritive and/or physiologically active substances for monogastric animals, comprising a core (12, 32) with an aqueous phase (16) with water-soluble active substances and a lipid phase (18) with liposoluble active components, said aqueous phase (16) being dispersed in said lipid phase (18), and a coating (14) of the core, comprising the following steps:
(a) preparing said aqueous phase by dispersing said water-soluble active substances in water and adding gelling reagents;
(b) injecting said aqueous phase into an oil to obtain a first emulsion of aqueous particles in the process of gelling in the oil;
(c) leaving to stand or heating said first emulsion to complete the reactions of gelation of the aqueous beads and to obtain gelled aqueous beads dispersed in the oil;
(d) adding said first emulsion to a mixture of at least one oil and at least one liquid wax;
(e) introducing all of said first emulsion and of said mixture of at least one oil and at least one liquid wax into an aqueous solution with stirring to obtain a second emulsion, said second emulsion comprising gelled aqueous particles dispersed in a lipid matrix, said lipid matrix itself being in the form of particles dispersed in said aqueous solution;
(f) cooling said second emulsion to a temperature below the melting temperature of said at least one wax to stabilize said lipid particles by solidifying said at least one wax;
(g) obtaining said lipid particles, ie said cores, by filtration or decantation; And
(i) forming the coating of said cores by successive immersions in baths of cationic and anionic polysaccharides. Preparation process according to Claim 1, in which, after having obtained the first emulsion of water-in-oil particles in step (b), the said first emulsion is subjected to high shear, preferably between 2,000 and 20 000 s-1, to reduce the size of the aqueous particles in the oil before gelation of said particles of the aqueous phase (step (b'). Preparation process according to one of Claims 1 and 2, comprising a final step (j) of drying the products under a stream of air at a temperature below 50°C, preferably between 18 and 40°C. Preparation process according to any one of the preceding claims, in which the said at least one wax is a crystallizable wax with a melting point below 90 degrees Celsius and preferably below 65 degrees Celsius. A method of preparation according to any preceding claim, wherein said gelling reagents comprise an anionic polysaccharide such as alginate, calcium salt and pyrophosphate. Preparation process according to Claim 5, in which the calcium salt is chosen from the group of calcium sulphate, carbonate and stearate. Preparation process according to any one of the preceding claims, in which all the aqueous solutions used comprise a controlled quantity of osmotic agent. Preparation process according to Claim 7, in which the said osmotic agent is chosen from the group of sugars, salts, water-soluble polymers, preferably with a molecular mass of less than 150 kg/mole, and combinations thereof. Process of preparation according to any one of the preceding claims, in which, after having obtained the said lipid particles in step (f) and before forming the coating in step (g), the said lipid particles are dispersed in a protein phase (step (f')). Preparation process according to any one of the preceding claims, in which, before injecting the said first emulsion into a mixture of oils and liquid waxes, a precise dose is added to the said mixture of oils and liquid waxes of the said substances fat-soluble active ingredients. Preparation process according to one of the preceding claims, in which, before injecting the said first emulsion into a mixture of at least one oil and at least one liquid wax, at least one oil is dispersed in the said mixture and at least one liquid wax an exfoliated clay phase in a lipid medium. Preparation process according to Claim 11, in which the exfoliation of a clay phase in a lipid medium is carried out in the presence of a surfactant, the said surfactant having the characteristic of having a cationic polar head. A method of preparation according to claim 12, wherein said surfactant is lecithin.