Particles containing an active agent and process for producing same

Abstract

The invention relates to particles (15) comprising an agglomeration of mutually cohesive grains having a substantially spherical shape, wherein each grain consists of a mixture comprising an active agent and a cohesion agent to bind the grains together. The process for producing these particles uses spray granulation.

Description

DESCRIPTION TITLE: Particles containing an active agent and their manufacturing process

[0001] The invention relates to particles containing at least one active agent. The particles are particularly suitable for incorporation during pelletizing or tablet manufacturing processes for the animal feed, food supplement, pharmaceutical, or cosmetic industries.

[0002] In the context of the present invention, "pelletization" (or "granulation") means a process consisting of assembling or agglomerating solid particles together in order to form larger elements in various geometric shapes such as spheres or cylinders.

[0003] The invention is described specifically with reference to the animal feed industry, but this does not limit its scope. Indeed, the issues described below, inherent to active ingredients and related to the animal feed industry, can also arise in the pharmaceutical industry, the human food supplement manufacturing industry, or the cosmetics industry.

[0004] Pelletizing animal feed is a preferred method compared to dry pelleting. This is because it offers several advantages: higher quality, fewer pathogens, less dust during manufacturing, easier handling, and more uniform dosing of active ingredients to improve feed productivity. These active ingredients can include enzymes (to improve digestibility), vitamins, proteins, antimicrobials, and pre- or probiotics.

[0005] However, other compounds, described as "aggressive" towards active agents, are also present in animal feed compositions, such as acidic or basic compounds which can be organic or inorganic, reducing sugars and hygroscopic substances (notably choline chloride or sodium chloride). have detrimental effects on these active agents such that they diminish their beneficial activity.

[0006] These adverse effects can occur during the storage of premixes or animal feed containing these active agents and compounds. For the purposes of this invention, "premix" means a pre-mixture of active agents such as those described above with various other organic or inorganic compounds (for example, carrier compounds such as limestone or clay), and in particular compounds that are considered "aggressive" towards the active agents. This pre-mixture is intended to be incorporated into animal feed. Indeed, during storage, redox reactions can occur in the presence of water within the premixes or animal feed, resulting in a significant reduction in the activity of active agents such as enzymes.

[0007] Furthermore, some active agents (particularly enzymes) can cause allergies when handled by operators.

[0008] Furthermore, it is known that feed manufacturing process steps involving harsh conditions (such as high humidity, temperatures, and compressive forces) can also be detrimental to the activity of active ingredients. Indeed, these ingredients (particularly enzymes) are not always stable when subjected to such conditions, especially during pelletizing for feed production.

[0009] Finally, some active ingredients are sensitive to humidity, particularly during the storage of animal feed which can last several years.

[0010] Storing these so-called "sensitive" active ingredients outside of premixes is not entirely satisfactory due to logistical reasons and therefore the increased cost of animal feed production. Furthermore, it does not resolve the aforementioned problem of stringent animal feed manufacturing process requirements, nor the risk of allergies among operators.

[0011] This is why it is common practice in industry, particularly in the animal feed industry but also in the pharmaceutical industry, to formulate these active agents in a protected form so that they can maintain their activity (and this even if they are subjected to drastic industrial process conditions and incorporated with other compounds said to be "aggressive" towards them) and to minimize the risk of allergies for operators.

[0012] There are different ways to protect active agents. For example, active agents can be incorporated into particles, more specifically: - in the nucleus of said particles, which is made of a porous material (for example, made of an inorganic salt such as sodium sulfate), by blocking its pores and thus remaining relatively on the surface of the nucleus, and / or - within a layer consisting of a binder (for example a sugar) which surrounds the nucleus of said particles, said nucleus, where applicable the binder layer, being coated by one or more protective layers (in other words "coating layers") so as to obtain particles containing protected active agents.

[0013] In this regard, patent EP 3 270 893 B1 describes examples of such particles.

[0014] It is important to emphasize that in these state-of-the-art particle embodiments, the protective layer is essential to properly protect the active agent present on the surface of the core (i.e., in a layer surrounding the core and / or in the pores on the core's surface). Indeed, in these state-of-the-art particle embodiments, the active agent is not homogeneously distributed throughout the particle volume and is therefore not optimally protected; this necessitates the presence of a protective layer.

[0015] Furthermore, patent application EP 1 072 612 A1 describes particles obtained from starch seeds that have been sprayed with a mixture of starch granules and pre-gelatinized starch, such that the seeds are coated with several layers of the mixture until a desired particle diameter is achieved. An active agent may be present within the different layers of the mixture. However, the active agent may not be present within the volume occupied by the seeds. Consequently, the active agent is not homogeneously distributed throughout the entire volume of the particles. Therefore, the active agent is not optimally protected.

[0016] In order to simplify the manufacture of thermostable particles containing active agents and to limit costs by reducing, for example, the number of raw materials, it would be advantageous to develop particles that do not require such protective layers while not lowering their ability to protect active agents.

[0017] Furthermore, it would be advantageous to have particles in which the protection performance of the active agents is enhanced compared to that of state-of-the-art particles. This improved protection of the active agents would also allow for a reduction in their quantity within these particles, thus lowering their production costs. In other words, thanks to this enhanced protection, the activity of these active agents could be achieved with particles containing fewer active agents than those in state-of-the-art particles.

[0018] Thus, there is still a real need to perfect the development of thermostable particles containing active agents which remain perfectly protected when these particles come into contact with other so-called "aggressive" compounds or when these particles are used in pelletizing or tablet manufacturing processes.

[0019] The inventors of the present invention have discovered, quite surprisingly, particles containing at least one active agent which perfectly fulfill these objectives.

[0020] The invention thus relates to a particle characterized in that it comprises an agglomeration of cohesive grains and is substantially spherical in shape, each grain being made up of a mixture comprising at least: - an active agent and - an agent for cohesion of said grains between themselves.

[0021] The cohesive agent allows the grains to stick together in such a way as to form an agglomeration of cohesive grains. This agglomeration has a roughly spherical shape.

[0022] The originality of the particles according to the invention lies in the fact that the cohesive agent contained in the mixture from which the grains are made ensures the cohesion of the grains between them in such a way as to obtain an agglomeration of grains of a roughly spherical shape. Thanks to this agglomeration of the grains, the active agent is distributed (or in other words "confined") homogeneously within said particles and is thus perfectly protected.

[0023] Unlike the state-of-the-art particles mentioned above, in which the active agent to be protected can be distributed either in a layer surrounding the nucleus of the particle, or by blocking the pores of a porous material constituting the nucleus of said particle and thus remaining relatively on the surface of said nucleus, in the particles according to the invention, the active agent is distributed, advantageously uniformly, throughout the entire volume (preferably spherical) of said particles.

[0024] In the particles according to the invention, since the active agent is not exclusively distributed on the surface of said particles but rather throughout their entire volume, a protective layer for the active agent is not required. Sufficient protection of the active agent without a protective layer is already achieved with the particles according to the invention thanks to the agglomeration of grains composed of the mixture as described above.

[0025] Indeed, and as demonstrated in the experimental section below, the inventors discovered quite surprisingly that the particles according to the invention without a protective layer provided protection of the active agent equivalent to that of the state-of-the-art particles described above, which have at least one protective layer around the nucleus of these particles.

[0026] The particles according to the invention can be thermostable.

[0027] The particles according to the invention can ensure good protection of the active agent against moisture, particularly during the storage of the products (for example, animal feed) in which they are incorporated.

[0028] The particle according to the invention can have a median diameter between 300 pm and 800 pm, preferably between 400 pm and 700 pm, more preferably between 500 pm and 600 pm.

[0029] Preferably, the particles according to the invention exhibit excellent sphericity. For example, sphericity can be evaluated from the parameters of circularity and / or roundness.

[0030] The circularity of a particle is determined according to the following mathematical formula (1): circularity = (4 x pi x area of ​​the particle) / (perimeter of the particle) (1)

[0031] The particle according to the invention exhibits good sphericity when its circularity is at least 0.85.

[0032] The roundness of a particle is determined according to the following mathematical formula (2): roundness = (4 x area of ​​the particle) / (pi x length of the major axis of the particle) (2)

[0033] The particle according to the invention exhibits good sphericity when its roundness is at least 0.85.

[0034] The fact that the particles according to the invention exhibit excellent sphericity is advantageous for being able to coat them with at least one protective layer in a qualitative manner, as described below. Indeed, if the particles do not exhibit good sphericity, pores may form on the surface of said protective layer during this coating step. These pores can allow water to penetrate the particles and thus reduce the activity of the active agents if they are sensitive to humidity.

[0035] Advantageously, the particles according to the invention have a tight particle size distribution, namely with a span less than or equal to 0.5.

[0036] The span is defined according to the mathematical equation (3) below: span = [D(v,0,9)-D(v,0,l)] / D(v,0,5) (3) in which: - D(v,0,9) represents the particle size for which 90% of the sample volume has a particle size smaller than this size; - D(v,0,l) represents the particle size for which 10% of the sample volume has a particle size smaller than this size, - D(V,0,5) represents the particle size for which 50% of the sample volume has a particle size smaller than this size.

[0037] The lower the span value, the more homogeneous the particle size distribution. A span value less than or equal to approximately 1 indicates a very homogeneous particle size distribution, and when the span value is less than or equal to approximately 0.5, the particles exhibit a perfectly homogeneous size distribution.

[0038] The active agent can be chosen from the group consisting of proteins (including enzymes, peptides and polypeptides), antimicrobial agents, amino acids and vitamins, taken alone or in mixtures thereof.

[0039] In preferred embodiments of the invention, the active agent is at least one protein selected from enzymes, peptides and polypeptides.

[0040] Preferably, the active agent is an enzyme. For example, it may be phytase, xylanase (especially endo-l,4-beta-xylanase), beta-glucanase, phosphatase, protease, amylase (especially alpha-, beta- or gluco-amylase), cellulase, lipase, cutinase, oxidase, transferase, reductase, hemicellulase, mannanase, esterase, isomerases, pectinase, lactase, peroxidase, laccase or redox enzymes (such as glucose oxidase, glutamate oxidase, lactate oxidase), taken alone or in a mixture of these.

[0041] In a preferred embodiment of the invention, the enzyme is selected from the group consisting of phytases, xylanases (for example, endo-l,4-beta-xylanase), phosphatases, proteases, amylases, esterases, redox enzymes, lipases, transferases, cellulases, and beta-glucanases, taken alone or in mixtures thereof. These enzymes are conventionally used in animal feed formulation.

[0042] In another preferred embodiment of the invention, the enzyme is selected from the group consisting of proteases, amylases, lipases, hemicellulases, redox enzymes, peroxidases, transferases, and cellulases, either alone or in mixtures thereof. These enzymes are commonly used in the formulation of food supplements or cosmetic products.

[0043] The particles according to the invention may comprise one or more different active agents (for example up to 3 different active agents).

[0044] In embodiments of the invention, the particles comprise a single enzyme or two or three different enzymes. For example, the particles may comprise a xylanase (e.g., endo-l,4-beta-xylanase) and a beta-glucanase, or a xylanase (e.g., endo-l,4-beta-xylanase), a beta-glucanase, and a phytase.

[0045] The enzymes described above are given by way of example and do not limit the scope of the invention. They may be any type of enzyme.

[0046] The active agent can be in solid or liquid form. When it is an enzyme, it can be in solid or liquid form. Preferably, it is in liquid form.

[0047] The quantity of active agents present in the particles according to the invention depends on their application. It is within the scope of a person skilled in the art to choose the quantity of active agents according to the application they intend for the particles according to the invention.

[0048] The particle according to the invention may comprise, in mass percentages expressed in relation to the total mass of said particle, between 10% and 90%, preferably between 15% and 70%, more preferably between 15% and 30%, even more preferably between 15% and 20%, of active agent.

[0049] The particles according to the invention exhibit higher active agent protection performance than prior art particles. Due to this improved active agent protection, the quantity of active agents contained in the particles according to the invention can be reduced, thereby lowering their production costs. Indeed, because of this enhanced active agent protection, an activity of said active agents equivalent to that of prior art particles can be achieved with particles according to the invention that contain fewer active agents than prior art particles.

[0050] The cohesion agent is configured to ensure cohesion between the grains.

[0051] It can consist of a hydrophilic polymer or a hydrophobic polymer.

[0052] In an advantageous embodiment of the invention, the cohesive agent is soluble in water.

[0053] In an advantageous embodiment of the invention, the cohesive agent with 15% by mass of dry extract in water has a viscosity at 25°C of between 5 mPa.s and 20 mPa.s.

[0054] When the active agent is an enzyme, the binding agent can be chosen to limit the enzyme's unfolding at the high temperatures of industrial processes such as those mentioned above. In other words, the binding agent can be selected so that the enzyme maintains its tertiary structure, even when subjected to high process temperatures.

[0055] The binding agent can be chosen from the group consisting of maltodextrin, lactose, maltose and starch, taken alone or in mixtures thereof.

[0056] Preferably, said binding agent is chosen from the group consisting of maltodextrin and starch.

[0057] The particle may comprise, in mass percentages expressed in relation to the total mass of said particle, between 10% and 90%, preferably between 15% and 85%, more preferably between 50% and 80%, of said cohesive agent.

[0058] The mixture constituting each grain may further comprise at least one additional compound. Advantageously, said additional compound is selected from the group consisting of sodium sulfate, calcium carbonate, and polyols.

[0059] The total mass content of the additional compound(s), expressed in relation to the total mass of said particle, may be between 5% and 35%, preferably between 5% and 10%.

[0060] In one embodiment of the invention, the particle further comprises at least one protective layer surrounding the agglomeration of cohesive grains. The presence of this protective layer or layers improves the protection of the active agents confined within the agglomeration of cohesive grains.

[0061] Advantageously, the protective layer helps to protect the active agent against moisture, particularly during the storage of the product containing the particles according to the invention, which can extend over several years.

[0062] In one embodiment of the invention, the particles comprise a plurality of protective layers which may be identical or different from each other.

[0063] For example, the particles may comprise one, two, three, or four protective layers, which may be identical or different from each other.

[0064] Each protective layer can have a thickness between 2 pm and 80 pm, preferably between 5 pm and 20 pm.

[0065] Furthermore, in this embodiment of the invention, the particle according to the invention may comprise, in mass percentages expressed relative to the total mass of said particle: - between 5% and 50%, preferably between 15% and 40%, of at least one protective layer, - between 50% and 95%, preferably between 60% and 85%, of said agglomeration of cohesive grains.

[0066] The choice of the component(s) of the protective layer is perfectly within the grasp of a person skilled in the art. Indeed, as explained above, it is standard practice to coat the core of the particles with at least one protective layer to safeguard the active agents they contain.

[0067] Thus, within the framework of the present invention, at least one protective layer may comprise one or more constituents commonly used for the implementation of such protective layers.

[0068] By way of non-limiting examples of the present invention, these may include polymers, sugars, proteins, lipids, oils, fatty acids, inorganic salts or gums, taken alone or in mixtures thereof.

[0069] Preferably, the constituent(s) of at least one protective layer have a melting point below 80°C. This is particularly suitable for to obtain qualitative protective layers that best protect the agglomeration of cohesive grains from particles.

[0070] The polymer may be selected from the group consisting of polysaccharides (e.g., alginates), polyvinyl alcohol, polyethylene glycol, polyvinyl pyrrolidone, polyacrylates, polyethylene oxides, polylactic acid, polyvinyl chloride, polyvinyl acetate, polyvinyl pyrrolidones, cellulose ethers, native or modified starches and their substituted derivatives, as well as their hydrolysates and copolymers thereof, hydroxypropyl methyl cellulose, methyl cellulose, carboxymethyl cellulose, and ethyl cellulose, taken alone or in mixtures thereof. Preferably, it is polyvinyl alcohol, methyl cellulose, or hydroxypropyl methyl cellulose.

[0071] With regard to starches, these can be native or modified starches from maize, sorghum, rice, wheat, rye, barley, oats, potato, tapioca or cassava.

[0072] Regarding sugars, these may include sucrose, corn syrup extract, molasses, glucose, fructose, and lactose.

[0073] Regarding proteins, these can include whey powder or concentrate, caseinates, soy protein concentrate, albumin, and gelatin.

[0074] With regard to lipids, oils, and fatty acids, these may include waxes (such as vegetable, mineral, and synthetic waxes: for example, carnauba wax, candelilla wax, beeswax, paraffin, and microcrystalline waxes), lecithin, fatty acids (for example, stearic, palmitic, linoleic, oleic, butyric, and arachidonic acids), as well as their sodium, potassium, calcium, and zinc salts, fats, and oils, in particular hydrogenated or partially hydrogenated fats and oils (for example, soybean, corn, cottonseed, sunflower, or linseed oil). Preferably, these are lecithin. In one embodiment of the invention, this is hydrogenated sunflower oil.

[0075] Regarding inorganic salts, these may include sulfate, citrate, chloride, carbonate, sulfite, phosphate, and phosphonate salts, as well as sodium, ammonium, potassium, calcium, magnesium, and zinc bicarbonate salts. Preferably, these are magnesium salts, sodium, ammonium or sodium sulfates. In one embodiment of the invention, this refers to sodium sulfate.

[0076] Regarding gums, these can include arabic gum, guar gum, agar, tragacanth gum, locust bean gum, carrageenan, and xanthan gum.

[0077] Preferably, the protective layer comprises at least one constituent selected from the group consisting of alginates, stearic acid, ethylcellulose, hydroxypropyl methyl cellulose, methyl cellulose, carboxymethyl cellulose and soybean, corn, cottonseed or linseed oil, taken alone or in mixtures thereof.

[0078] The at least one protective layer may further include at least one constituent selected from the group consisting of plasticizers, lubricants, pigments and powders such as talc, bentonite, kaolin, magnesium silicate, calcium carbonate and chitosan, taken alone or in mixtures thereof.

[0079] In one embodiment of the invention, the particle comprises a l ère a protective layer and a 2 ème protective layer, said l ère the protective layer comprises at least one inorganic salt, preferably sodium sulfate, and said 2 ème a protective layer surrounds the l ère The protective layer contains stearic acid or hydrogenated sunflower oil. This method of constructing the protective layers provides optimal protection for the active ingredient.

[0080] Preferably, in this embodiment of the invention, the active agent is an enzyme.

[0081] Preferably, in this embodiment of the invention, the binding agent is maltodextrin.

[0082] Thus, in one embodiment of the invention, the active agent is an enzyme, the binding agent is maltodextrin, and the particle further comprises a ère and a 2 ème protective layers, said l ère the protective layer comprises at least one inorganic salt, preferably sodium sulfate, and said 2 ème a protective layer surrounds the l ère protective layer and includes stearic acid or hydrogenated sunflower oil.

[0083] Preferably, the particles according to the invention are incorporated into a premix as defined above.

[0084] Therefore, the invention also relates to a premix comprising at least some particles according to the invention as described above. This premix may comprise, in mass percentages expressed relative to the mass of said premix, between 0.2% and 10%, preferably between 0.1% and 3%, of said particles. For example, if the active agent is an enzyme, the enzymatic activity in the premix may be approximately 500 U / g.

[0085] The premix can be incorporated into animal feed.

[0086] Therefore, the invention also relates to an animal feed which includes at least the premix according to the invention.

[0087] Said animal feed may comprise, in mass percentages expressed in relation to the mass of said animal feed, between 0.5% and 6%, preferably between 2% and 5%, of said premix according to the invention.

[0088] In another embodiment of the invention, the particles according to the invention are directly incorporated into animal feed.

[0089] When the particles according to the invention are incorporated into animal feed, the quantity of said particles per tonne of said feed can be up to approximately 5000 g, and preferably between approximately 25 g and approximately 400 g. Indeed, the quantity of each of the constituents of animal feed is generally between 0.001 g and 400 g per tonne of said feed.

[0090] Thus, the quantity of active agent per tonne of said animal feed can be between approximately 0.0001 g and approximately 80 g.

[0091] The invention also relates to a method for manufacturing particles according to the invention which is characterized in that it comprises at least the following steps: a) a mixture is prepared which comprises at least the active agent and the cohesive agent, and optionally at least one solvent so that said mixture can be subjected to spray granulation, b) the mixture thus obtained in step a) is subjected to spray granulation so as to obtain said particles according to the invention.

[0092] Advantageously, the manufacturing process further includes at least one step c) of coating the particles obtained at the end of step b) so as to cover them with at least one protective layer.

[0093] In step a), the mixture may optionally include at least one additional compound as described above in the description of the particles according to the invention.

[0094] The active agent, the cohesive agent, any additional compounds, as well as the constituents of at least one protective layer have been described above in the description of the particles according to the invention.

[0095] In step a), the mixture may optionally include at least one solvent.

[0096] Indeed, at least one solvent may be added to the other constituents of the mixture in step a) in order to be able to subject said mixture to spray granulation if this spray granulation is not feasible with only these other constituents of said mixture.

[0097] It is perfectly within the capabilities of a person skilled in the art to decide whether to add at least one solvent to the mixture in step a), which includes at least the active agent and the binding agent, in order to then carry out step b), spray granulation. It is also within the capabilities of a person skilled in the art to determine the quantity of solvent to add to the mixture in step a). Indeed, the spray granulation technique is perfectly understood by a person skilled in the art.

[0098] The solvent can be water, preferably demineralized water.

[0099] Preferably, the mixture obtained at the end of step a) has a viscosity at 25°C between 10 mPa·s (cP) and 50 mPa·s (cP), preferably between 12 mPa·s (cP) and 48 mPa·s (cP). This viscosity of the mixture is particularly suitable for spray granulation, during which the mixture will be sprayed through at least one nozzle. In other words, advantageously, the viscosity of the mixture from step a) is compatible with the use of the nozzle through which it is sprayed.

[0100] Advantageously, the mixture is stable over time. This means that it does not exhibit phase separation or mass gain over time, even though spray granulation can last several hours.

[0101] The choice of all the constituents of the mixture in step a) and their respective quantities is perfectly within the reach of a person skilled in the art who will be able to determine them without difficulty according to the final composition of the particles according to the invention he wishes to obtain.

[0102] In step a), advantageously, the binding agent, as well as any additional compounds, are gently incorporated into the active agent.

[0103] Step a) is preferably carried out at room temperature.

[0104] At the end of step a), the mixture is preferably homogeneous.

[0105] Preferably, in step a), said mixture is prepared with a paddle mixer, for example at a speed between 300 rpm and 700 rpm, so as to make the mixture homogeneous.

[0106] In one embodiment of the invention, during the execution of step a), the active agent may be in the form of a concentrate of active agents suspended in an aqueous solution.

[0107] The said concentrate of active agents may advantageously present a dry extract of between 10% and 50%, preferably between 25% and 35%.

[0108] This could be an enzyme concentrate. For example, there is the enzyme concentrate marketed by the company Danisco under the trade name "Rovabio Advance SD".

[0109] The cohesive agent may also have a dry extract, for example of 98%, and therefore include some water.

[0110] In other words, in these embodiments of the invention, in the mixture obtained at the end of step a) a part of the solvent (for example water) which may be necessary to add in order for said mixture to be suitable for carrying out spray granulation is supplied by the concentrate of active agents and / or the cohesive agent.

[0111] The implementation of spray granulation in step b) is perfectly within the capabilities of a person skilled in the art. Step b) of spray granulation can advantageously be carried out with a device such as is schematically represented in Figure 1 and described below.

[0112] During step b) of spray granulation, the solvent (for example water, in particular demineralized water) contained in the mixture obtained at the end of step a) is evaporated, preferably until said mixture has a mass content of said solvent which is less than 6%, preferably less than 4%.

[0113] Advantageously, the manufacturing process further includes at least one step c) of coating the particles obtained at the end of step b) so as to cover them with at least one protective layer.

[0114] The implementation of step c) of coating is perfectly within the capabilities of a person skilled in the art. It can, for example, be carried out in a fluidized air bed.

[0115] The invention will be better understood with the help of: - the experimental part carried out with particles according to the invention and comparative particles, - the detailed description set out below with reference to the attached drawing representing, by way of non-limiting example, one embodiment of the device used to carry out step b) of spray granulation of the particle manufacturing process according to the invention.

[0116] [Fig. 1] Figure 1 is a schematic representation of a device for implementing step b) of the particle manufacturing process according to the invention.

[0117] EXPERIMENTAL SECTION:

[0118] Experiments were carried out on particles according to the invention and comparative particles from the state of the art.

[0119] I - Preparation of particles according to the invention without a protective layer:

[0120] Five types of particles according to the invention were prepared according to steps a) to b) of the manufacturing process according to the invention.

[0121] These 5 types of particles included enzymes as active agents. More specifically, they were endo-l,4-beta-xylanase and beta-glucanase.

[0122] During step a) of the particle manufacturing process, these enzymes were added to the mixture in the form of an enzyme concentrate. This was the enzyme concentrate marketed by Danisco under the trade name "Rovabio Advance SD". It had a dry extract content of 28% by mass.

[0123] The binding agent ensuring the cohesion of the grains was maltodextrin which had a dry extract of 98%.

[0124] During step a), the solvent was demineralized water.

[0125] Step a) of the manufacturing process was carried out at room temperature, using a paddle mixer set at a speed of approximately 600 rpm, preparing a homogeneous mixture comprising: - the enzyme concentrate described above; - a powder of the aforementioned maltodextrin; - water in such quantity that the said mixture had a dry extract of 30%.

[0126] The 5 types of particles according to the invention differed from each other only in the quantities of enzyme concentrate, maltodextrin, and demineralized water that were used to prepare the mixture in step a) of the manufacturing process of said particles.

[0127] Table 1 below details, for each type of particle, the quantities of enzyme concentrate, maltodextrin, and demineralized water: - 1 er type of particles, hereinafter referred to as INV1 particles, - 2 ème type of particles, hereinafter referred to as INV2 particles, - 3 ème type of particles, hereinafter referred to as INV3 particles, - 4 èmetype of particles, hereinafter referred to as INV4 particles, - 5 ème type of particles, hereinafter referred to as INV5 particles.

[0128] Table 1

[0129] From these values ​​of the masses of enzyme concentrate and maltodextrin detailed in Table 1 above, and knowing that the enzyme concentrate had a dry extract of 28% and the maltodextrin a dry extract of 98%, we can calculate the mass contents of dry extract of enzyme concentrate and dry extract of maltodextrin expressed in relation to the sum of the masses of dry extracts of enzyme concentrate and maltodextrin which were implemented for each of the 4 types of particles.

[0130] Table 2 below details these mass contents of dry extract of enzyme concentrate and maltodextrin for each type of particle INV1 to INV5.

[0131] Table 2

[0132] Table 2 shows that particles INV1 to INV5 had varying mass contents of dry extract of enzyme concentrate and maltodextrin.

[0133] Next, the mixture thus obtained at the end of step a) was subjected to granulation by spraying in an apparatus 1 which is schematically represented in figure 1.

[0134] This apparatus 1 comprises: - a container 2 configured to contain the mixture 3 obtained at the end of step a) of the manufacturing process and as described above, - a peristaltic pump 5 with a flow rate between 945 and 1000 g / hour, - a 1 er means of conveying said mixture 3 from container 2 to pump 5, - a nozzle 8 with a needle having an internal opening diameter of 1.2 mm and an atomization pressure of 2.5 bar, said nozzle 8 was arranged substantially vertically on the bottom wall 18 of a tank 7 in which the granulation by spraying was carried out, - a 2 ème means of conveying the mixture 3 from the pump 5 to the nozzle 8, 6 - a 1 er air injector (called "process air" because it is used for the implementation of spray granulation) 12 in tank 7, - a 1 er air flap 9a with an opening of +15° to the left and a 2 ème 9b air damper with a +30° opening to the right, - a 3 ème means of conveying 19 the particles formed in tank 7 to a separator 11, - the separator 11 comprising an elongated "zig-zag" shaped portion 20 configured to implement continuous pneumatic separation, as well as a èreend 20a and a 2 ème end 20b, said 2 ème end 20b being in fluidic connection on the one hand with said 3 ème means of conveying 19 the particles formed in the tank 7 to the separator 11 and on the other hand with a 4 ème means of conveying excessively fine particles from separator 11 to tank 7, 10 - a 2 ème air injector 13 (called "pressure air" to allow the separation of particles within the separator 11 by continuous pneumatic separation) at the level of the l ère end 20a of separator 11, - a container 14 for receiving the particles 15 obtained at the end of step b) of spray granulation which are sufficiently dense to pass through the separator 11, - an air outlet 21 to prevent overpressure in the tank 7, ensure the renewal of the aforementioned process air and thus evacuate humid air, - a filtration system 22 configured to retain inside the tank 7 the particles being formed by spray granulation, and thus prevent them from exiting the tank 7 through the aforementioned air outlet 21.

[0135] In Figure 1, reference 16 designates the movement of air and particles being manufactured by spray granulation in tank 7. Reference 23 designates the mixture 3 which is sprayed by nozzle 8. Reference 17 designates the airflow which is injected into tank 7 by Venturi effect.

[0136] Device 1 was operating in continuous mode.

[0137] The air temperature at level 1 er The temperature of air injector 12 was between 56°C and 60°C. The air flow rate injected by the 1 er The air injector 12 in tank 7 was between 100 and 150 m 3 / hour. It was dry, desaturated air.

[0138] The 1er and 2 ème Air flaps 9a, 9b made it possible to obtain a homogeneous airflow in tank 7.

[0139] The air temperature at the air outlet 21 was between 32°C and 39°C.

[0140] In addition, compressed air at a pressure of 0.8 bar was injected through the 2 ème air injector 13 at the separator 11 so that particles with a median diameter of at least 500 pm pass through the entire separator 11, then fall by gravity to be collected in the container 14, and that the other particles, being too small, are pushed upwards and rise in the portion 20 in a "zig-zag" pattern up to the 2 ème end 20b of separator 11 to be redirected into tank 7 via 4 èmeconveying means 10 which consisted of a flexible plastic tube. Particles that were too small were again subjected to granulation by spraying in the tank 7 until they reached a median diameter of at least 500 pm.

[0141] The container 14 allowed the collection of the particles 15 according to the invention which had passed through the entire separator 11.

[0142] Comparative particles of the state of the art

[0143] The comparative state-of-the-art particles were particles marketed by Adisseo France SAS under the trade name "Rovabio Advance T-Flex".

[0144] They contained, in mass percentages expressed relative to the mass of said comparative particles: - 15% of the same enzyme concentrate as for the particles according to the invention (namely the Rovabio Advance SD enzyme concentrate), - 20% calcium carbonate, - 15% maltodextrin, and - 50% stearic acid.

[0145] The comparative particles comprised a calcium carbonate core with a diameter of approximately 285 pm covered with a ère a layer approximately 65 µm thick containing a mixture of maltodextrin and enzyme concentrate. This layer ère The layer was itself covered with a protective layer approximately 55 µm thick, consisting of stearic acid. Thus, in the comparative particles, the enzymes of the enzyme concentrate were protected by the protective layer of stearic acid.

[0146] Measurements performed on the particles according to the invention and the comparative particles

[0147] The size and size distribution of the particles according to the invention and comparatively were measured using a laser particle size analyzer (MasterSizer S model marketed by Malvern Instruments Ltd) in solid mode. The result was obtained after counting 5000 particles.

[0148] Table 3 below details for comparative particles and the 5 types of particles according to the invention (namely INV1, INV2, INV3, INV4 and INV5): D(v,0,l), D(v,0,5), D(v,0,9) expressed in pm and the span as defined above.

[0149] Table 3

[0150] Based on the detailed results in Table 3 above, and in particular on the span values, we note that: - the 5 types of particles according to the invention have lower span values ​​than the comparative particles, and this is particularly true for particles INV1, INV3, INV4 and INV5: the particles according to the invention thus have a more homogeneous size distribution than the comparative particles, - The 5 types of particles according to the invention have homogeneous size distributions. The INV5 particles are very homogeneous in size (span of 0.40) and the INV1 particles have a size distribution exhibiting excellent homogeneity with a span value of only 0.34.

[0151] II - Preparation of particles according to the invention with a protective layer:

[0152] Next, the 5 types of particles according to the invention were subjected to an additional coating step, namely the optional step c) of the manufacturing process according to the invention.

[0153] Three coating compositions were used.

[0154] The l ère The coating composition was obtained by solubilizing 73 g of an 8% dry extract ethylcellulose solution in 847 g of ethanol at room temperature using a paddle stirrer. The dry matter mass content of the ère The coating composition thus obtained was 8%.

[0155] The 2 ème The coating composition was obtained by melting 133 g of 92% reactive grade stearic acid using a hot plate.

[0156] The 3 ème The coating composition was obtained by solubilizing 491 g of sodium sulfate at 80°C in 1062 g of demineralized water.

[0157] The coating stage with the l ère , the 2 ème or the 3rd ème The coating composition was implemented on the particles according to the invention in a fluidized air bed.

[0158] More specifically, 3 different coatings described below were applied to the INV1 particles in order to obtain 3 new types of coated particles according to the invention: INVIA, INVIB and INV1C: - INV1A coated particles were obtained from INV1 particles which were coated with a single protective layer consisting of the 2 ème coating composition in quantities such that the mass percentages expressed in relation to the total mass of these INV1A coated particles were: 75% of the INV1 particles and 25% of this protective layer; - INV1B coated particles were obtained from INV1 particles which were coated with a single protective layer consisting of the l ère coating composition in quantities such that the mass percentages expressed in relation to the total mass of these coated particles INV1B were: 90% of the INV1 particles and 10% of this protective layer; - INV1C coated particles were obtained from INV1 particles that were coated with a ère protective layer made of the l ère coating composition, then this l ère the protective layer was itself covered with a 2 ème protective layer of the 2 ème coating composition in quantities such that the mass percentages expressed relative to the total mass of these coated INV1C particles were: 77% INV1 particles, 8% of the l ère protective layer and 15% of the 2 ème protective layer.

[0159] Two different coatings, described below, were applied to the INV2 particles to obtain two new types of coated particles according to the invention, INV2A and INV2B: - INV2A coated particles were obtained from INV2 particles which were coated with a single protective layer consisting of the 2 èmecoating composition in quantities such that the mass percentages expressed in relation to the total mass of these INV2A coated particles were: 75% of the INV2 particles and 25% of this protective layer; - INV2B coated particles were obtained from INV2 particles which were coated with a single protective layer consisting of the 2 ème coating composition in quantities such that the mass percentages expressed in relation to the total mass of these INV2B coated particles were: 50% of the INV2 particles and 50% of this protective layer.

[0160] Two different coatings, described below, were applied to the INV3 particles in order to obtain two new types of coated particles according to the invention, INV3A and INV3B: - INV3A coated particles were obtained from INV3 particles which were coated with a single protective layer consisting of the lère coating composition in quantities such that the mass percentages expressed in relation to the total mass of these INV3A coated particles were: 90% of INV3 particles and 10% of this protective layer; - INV3B coated particles were obtained from INV3 particles which were coated with a single protective layer consisting of the 2 ème coating composition in quantities such that the mass percentages expressed in relation to the total mass of these INV3B coated particles were: 75% of INV3 particles and 25% of this protective layer;

[0161] The coating described below was applied to the INV4 particles to obtain a new type of coated particles according to the INV4A invention: - INV4A coated particles were obtained from INV4 particles which were coated with a single protective layer consisting of the l èrecoating composition in quantities such that the mass percentages expressed in relation to the total mass of these INV4A coated particles were: 95% of INV4 particles and 5% of this protective layer;

[0162] Two different coatings, described below, were applied to the INV5 particles in order to obtain two new types of coated particles according to the invention, INV5A and INV5B: - INV5A coated particles were obtained from INV5 particles which were coated with a single protective layer consisting of the 3 ère coating composition in quantities such that the mass percentages expressed in relation to the total mass of these INV5A coated particles were: 45% of the INV5 particles and 55% of this protective layer; - INV5B coated particles were obtained from INV5 particles that were coated with a ère protective layer consisting of the 3ère coating composition, then this l ère the protective layer was itself covered with a 2 ème protective layer of the 2 ème coating composition in quantities such that the mass percentages expressed relative to the total mass of these coated particles INV5B were: 31% of the particles INV1, 41% of the l ère protective layer and 25% of the 2 ème protective layer;

[0163] Thus, the INV1 to INV5 particles constituted the "cores" of these other particles according to the invention which had one or two protective layers and whose particle size characteristics are detailed in Table 4.

[0164] More specifically, Table 4 below details for the coated particles according to the invention INVIA to INVIC, INV2A, INV2B, INV3A, INV3B, INV4A, INV5A and INV5B: D(v,0,l), D(v,0,5), D(v,0,9) and the span.

[0165] Table 4

[0166] Based on the detailed results in Table 4 above, and in particular on the span values, we note that: - all these coated particles according to the invention have a span value of less than 1: they thus have a homogeneous size distribution, - The particles according to the invention INVIA, INV2B, INV3B, INV4A, INV5A and INV5B, which have protective layers different from each other, exhibit very low span values: their size distribution is perfectly homogeneous. This demonstrates that the particles according to the invention can exhibit perfectly homogeneous size distributions, and this with very varied protective layer compositions.

[0167] Tables 5 and 6 below detail, for particles INV1 to INV5, the coated particles INV1A to INVIC, INV2A, INV2B, INV3A, INV3B, INV4A, INV5A, INV5B, as well as the comparative particles: - the enzyme content expressed in mg / g; - the activity of endo-l,4-beta-xylanase expressed in U / g; - the relative humidity level measured on 2 g of particles at 105°C; - the activity of water; - the packed density dlO (g / L); - roundness.

[0168] The activity of endo-1,4-beta-xylanase was measured using a protocol based on the enzymatic hydrolysis of the xylosidic bridges in a soluble solution of wheat arabinoxylan and arabinose-substituted 1,4-xylan polysaccharide. Endo-1,4-beta-xylanase hydrolyzes the xylosidic bridges of xylan. The enzymatic activity is therefore proportional to the reduction in viscosity of this soluble solution in the presence of the enzyme being measured.

[0169] The relative humidity was determined using an infrared balance marketed under the trade name HS153 by Mettler Toledo. Approximately 2 g of the sample of tested particles were placed in a pre-tared aluminum dish. Once the balance was closed, the sample was heated to 105°C to remove as much moisture as possible in order to determine the relative humidity.

[0170] The water activity was determined at room temperature using the Aw-meter device marketed under the trade name Labswift-aw by the company Novasina.

[0171] The packed density dlO was determined as follows: a sample of the tested particles was placed in a graduated plastic cylinder, and then the density dO was calculated by dividing the mass by the volume multiplied by 100. The cylinder then The specimen was placed in an automated compacted density analyzer, marketed under the trade name Autotap by Anto Paar, which allowed the specimen to be tapped 10 times. The density dlO was obtained by dividing the mass by the volume of the compacted sample, then multiplying by 100.

[0172] Microscopic observations were performed using a Techsystems microscope equipped with a Navitar optical camera. The particle sample was placed on a slide. Images were captured at various magnifications using Archimed software. The microscopic images were then processed using ImageJ software to determine the roundness of the tested particles. This parameter was determined by tracing the outline of the particles.

[0173] The roundness was determined according to the mathematical formula (2) detailed above.

[0174] Table 5

[0175] Based on the detailed results in Table 5 above, we note that: - these particles according to the invention exhibit excellent sphericity because their roundness is always greater than 0.8; - the activity of endo-l,4-beta-xylanase) increases with increasing enzyme content; - the relative humidity is very low (between 3.5% and 4%) and at a value that is quite acceptable to avoid the degradation of enzymes; - the water activity is also very low and of a value that is also quite acceptable to avoid the degradation of enzymes.

[0176] Table 6

[0177] Based on the detailed results in Table 6 above, we note that: - these coated particles according to the invention exhibit excellent sphericity because their roundness is always greater than a value of 0.8. They exhibit better sphericity than the comparative particles; - the relative humidity of these particles according to the invention is lower than that of the comparative particles.

[0178] Next, the thermostability to pelletization of particles INV1 to INV5, INV1A to INV1C, INV2A, INV2B, INV3A, INV3B, INV4A, INV5A, INV5B and comparatives was tested.

[0179] All these particles were introduced at a rate of 200 g / tonne into a poultry premix, then extruded in a press at 90°C to obtain granules.

[0180] The pelletizing conditions were as follows: - press output: 44 to 46 kg / hour; - temperature at the outlet of the conditioner: 90°C; - temperature of the die: 85°C; - steam output: 2.6 kg / hour; - steam pressure: 1.6 bars; - Die size: 4 mm x 24 mm.

[0181] The maintenance rate of enzyme activity is the ratio of the activity of the enzymes contained in the pellets to the activity of said enzymes before the incorporation of the particles into the animal feed. It is determined according to the following mathematical formula (4): Maintenance rate of ['enzymatic activity = in which: - A is the activity of the enzymes contained in the animal feed pellets (in other words, after pelletizing) expressed in U / kg, - B is the activity of the enzymes before incorporation of the particles into the animal feed, expressed in U / g. - C is the quantity of particles incorporated into the food expressed in g / T.

[0182] Table 7 below details the rates of maintenance of enzymatic activity obtained for the particles according to the invention INV1 to INV5 and the comparative particles.

[0183]

[0184] Table 7

[0185] Based on the detailed results in Table 7 above, it can be seen that all these particles according to the invention have a rate of enzymatic activity retention comparable to that of the comparative particles, for which the rate of enzymatic activity retention can range from 47% to 67%. Thus, the particles according to the invention, although lacking any protective layer, protect enzymes with an efficiency almost equivalent to that of the prior art comparative particles that include a protective layer.

[0186] Table 8 below details the rates of maintenance of enzymatic activity obtained for the coated particles according to the invention INV1A to INVIC, INV2A, INV2B, INV3A, INV3B, INV4A, INV5A and INV5b and the comparative particles.

[0187] Table 8

[0188] Based on the detailed results in Table 8 above, we note that: - these coated particles according to the invention all have an excellent rate of maintenance of enzymatic activity which is much higher than that of the comparative particles; - the INV1CJNV3B and INV5B particles exhibit the best rate of maintenance of enzymatic activity.

[0189] Comparing the results in Table 7 with those in Table 8, we note that adding one or more protective layers improves the rate of maintenance of the enzymatic activity of the particles according to the invention.

Claims

CLAIMS 1. Particle (15), characterized in that it comprises an agglomeration of grains which are cohesive with each other and which is of substantially spherical shape, each grain being made up of a mixture which comprises at least: - an active agent and - an agent for the cohesion of said grains between them.

2. Particle (15) according to claim 1, characterized in that it has a median diameter of between 300 pm and 800 pm, preferably between 400 pm and 700 pm, more preferably between 500 pm and 600 pm.

3. Particle (15) according to claim 1 or 2, characterized in that the active agent is chosen from the group consisting of proteins, antimicrobial agents, amino acids and vitamins, taken alone or as a mixture thereof.

4. Particle (15) according to claim 3, characterized in that the active agent is at least one protein chosen from enzymes, peptides and polypeptides.

5. Particle (15) according to any one of claims 1 to 4, characterized in that it comprises, in mass percentages expressed relative to the total mass of said particle, between 10% and 90%, preferably between 15% and 70%, more preferably between 15% and 30%, of active agent.

6. Particle (15) according to any one of claims 1 to 5, characterized in that the cohesion agent is chosen from the group consisting of maltodextrin, lactose, maltose and starch, taken alone or as a mixture thereof.

7. Particle (15) according to any one of claims 1 to 6, characterized in that it comprises, in mass percentages expressed relative to the total mass of said particle, between 10% and 90%, preferably between 15% and 85%, more preferably between 50% and 80%, of said cohesion agent.

8. Particle according to any one of claims 1 to 7, characterized in that it further comprises at least one protective layer which surrounds said agglomeration of cohesive grains between them.

9. Particle according to claim 8, characterized in that the protective layer comprises at least one constituent chosen from the group consisting of alginates, stearic acid, ethylcellulose, hydroxypropyl methyl cellulose, methyl cellulose, carboxymethyl cellulose and soybean, corn, cottonseed or linseed oil, taken alone or as a mixture thereof.

10. Particle according to claim 8, characterized in that the active agent is an enzyme, the cohesion agent is maltodextrin and in that said particle comprises a l ère and a 2 ème protective layers, said l ère protective layer comprises at least one inorganic salt, preferably sodium sulfate and said 2 èmeprotective layer surrounds the l ère protective layer and includes stearic acid or hydrogenated sunflower oil.

11. Premix, characterized in that it comprises at least particles according to any one of claims 1 to 10.

12. Animal feed, characterized in that it comprises at least the premix according to claim 11.

13. Method for manufacturing particles (15) according to any one of claims 1 to 7, characterized in that it comprises at least the following steps: a) a mixture is prepared which comprises at least the active agent and the cohesion agent, and optionally at least one solvent so that said mixture can be subjected to spray granulation, b) the mixture thus obtained in step a) is subjected to spray granulation so as to obtain said particles.

14. Manufacturing method according to claim 13 of particles according to any one of claims 8 to 10, characterized in that it further comprises at least one step c) of coating the particles (15) obtained at the end of step b) so as to cover them with at least one protective layer.

Images