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1. WO2013153220 - MICROCAPSULES CONTAINING AN OXIDIZABLE ACTIVE, AND A PROCESS FOR PREPARING THE SAME

Note: Text based on automatic Optical Character Recognition processes. Please use the PDF version for legal matters

[ EN ]

MICROCAPSULES CONTAINING AN OXIDIZABLE ACTIVE, AND A PROCESS

FOR PREPARING THE SAME

The present invention relates to microcapsules containing an oxidizable active, and a process for preparing the same.

There is an increasing need in the industry, for example in the food, pharmaceutical or cosmetics industry, for protection of active agents from the medium that surrounds said active agents in particular to achieve a better conservation of said active agents.

One of the main issues of encapsulation is to be able to protect drugs from external medium but also to allow the right release or the right access to this drug when needed. This access is very often possible through a quick or controlled release in the medium, due to chosen properties of the encapsulating agent.

This dual aim of protection and release becomes more complex as soon as exchanges between drugs and medium need to be kept out of direct interactions in-between drug and external medium. S.K. Tarn and al. have shown (in Vandamme et al Microencapsulation; Tec & Doc; 2007; Chapter 11) these issues when the microencapsulation aims to allow therapeutic effects through useful component exchanges, components which are able to cross the microencapsulation barriers while preserving drugs from being in direct contact with other potentially damaging components, if they had entered the microcapsule.

In case of oxidizable drugs, the issue is to be able to get microcapsules which are able to protect these drugs from oxidation, and to protect the external medium from component issued from oxidation of said drugs.

Different kind of encapsulating agents can target this type of protection, but polysaccharides are the most often used. They are mainly used under bead forms containing solutions and cross-linked in salt or cations solutions. Such beads are then stored in wet forms as suspensions particles in solutions.

Chen and al. Journal of Controlled Release 2004, 96, 285-300 reported that such beads of polysaccharides can protect bioactive molecules from harsh acidic conditions such as stomach environment. But no works seem to have been made on the use of such a protection of the external medium from oxidizable agents which could decompose media components.

Moreover, the use of such polysaccharides is mainly achieved with cross-linking through dropping of aqueous solutions containing said polysaccharides into aqueous solutions containing salts.

However, the obtained beads suffer several drawbacks: they are mainly stored in aqueous solution, rendering their handling difficult, their production and their transportation expensive. In addition, said beads cannot be used directly in powder preparation, in particular food powder compositions, or in tablets, in particular for pharmaceutical uses.

No studies have been made on powder microcapsules allowing dry forms of drug protections through process avoiding aqueous solution to create the insoluble external protection of the microcapsule.

Thus, one aim of the present invention is on the one hand to encapsulate oxidizable active products to protect the media from their action, and on the other hand to implement new processes allowing the manufacture of these microcapsules with no absolute need to submerge the microcapsules in a cross linking bath of an aqueous salt solution.

Another aim of the present invention is to provide microcapsules able to protect an active from oxidation by a given alimentary, cosmetically or pharmaceutically acceptable medium in which said microcapsules are placed.

Another aim of the present invention is to provide microcapsules able to protect the alimentary, cosmetically or pharmaceutically acceptable medium in which said microcapsules are placed from the active contained in said microcapsules.

Thus, the present invention relates to a microcapsule consisting in or containing:

• a core consisting in or comprising an oxidizable active (OA), and

· a water insoluble coating obtained from an encapsulating agent (EA), said coating surrounding said core.

By microcapsule is meant a particle with a size from 1 μιη to a 3 mm, comprising an external coating that isolates an encapsulated core from the external medium.

By core is meant the material inside the microcapsule.

By coating is meant the wall surrounding the core of said microcapsule.

By "water insoluble coating" is meant a coating, the water solubility of which is low enough to prevent said active to be released from the microcapsule, when said microcapsule is placed in an aqueous-based alimentary, cosmetically or pharmaceutically acceptable medium.

The insolubilization of a microcapsule, and thus the fact that said coating prevents said active to be released from said microcapsule is for example determined by the measurement of particle size in water, for instance with a laser particle sizer.

By "prevent said active to be released from the microcapsule" is meant that, when said microcapsule is placed in said medium, the concentration of active in the medium

surrounding said microcapsule is below 5% in weight at 25°C, in particular below 1% in weight at 25°C.

By "oxidizable active" is meant an active that is capable of being oxidized.

By "active being oxidized" is meant a reducing agent oxidized by having its electrons taken away.

The tendency of an active of having its electrons taken away and thereby be oxidized is in particular measured by its redox potential, as known by those skilled in the art: an active is likely to be oxidized by an element of the external medium if the redox potential of said element is superior to the redox potential of said active.

By "encapsulation agent" is meant a water insoluble agent constituting said water insoluble coating, or a water soluble agent forming said water insoluble coating after a modification of its chemical state.

The term "modification of its chemical state" means in particular a chemical reaction or a pH modification.

The present invention also relates to a microcapsule consisting in or containing:

• a core consisting in or comprising an oxidizable active (OA), the outer part of said core being in a solid form, and

• a water insoluble coating obtained from an encapsulating agent (EA), said coating surrounding said core,

with the proviso that:

- said core does not consist in or comprise a metal oxide, and

- said coating does not comprise a disintegrant, in particular sodium starch glycolate.

By "outer part" is meant the part of said core which is in contact with said coating. By "solid form" is meant a crystalline, semi-crystalline or amorphous state.

In an advantageous embodiment, the present invention relates to a microcapsule, wherein said core is under solid form.

In a particularly advantageous embodiment, the present invention relates to a microcapsule, wherein said core is crystalline. In this case, said oxidizable active is necessarily crystalline.

In another particularly advantageous embodiment, the present invention relates to a microcapsule, wherein said core is crystalline and solid, i.e. without any space or air cavities.

In another particularly advantageous embodiment, the present invention relates to a microcapsule, wherein said core is crystalline and contains at least one space or air cavity.

In another particularly advantageous embodiment, the present invention relates to a microcapsule, wherein said core is crystalline and has a water content less than 10%, in particular less than 6%, by weight.

In another particularly advantageous embodiment, the present invention relates to a microcapsule, wherein said core is under solid form and amorphous.

In another particularly advantageous embodiment, the present invention relates to a microcapsule, wherein said core is amorphous and contains at least one space or air cavity, said core being in particular obtained by spray drying.

In another particularly advantageous embodiment, the present invention relates to a microcapsule, wherein said core is amorphous and has a water content less than 10%, in particular less than 6%, by weight.

In an advantageous embodiment, the present invention relates to a microcapsule, wherein the inner part of said core contains the oxidizable active (OA), said OA being in a liquid form, in particular in an oily form, or in a viscous oil form, or in a pasty form.

In a particularly advantageous embodiment, the present invention relates to a microcapsule, wherein said inner part of said core is a solid comprising the OA in a liquid form, in particular in an oily form, or in a viscous oil form, or in a pasty form.

In an advantageous embodiment, the present invention relates to a microcapsule, wherein said core does not consist in or comprise phospholipids.

In an advantageous embodiment, the present invention relates to a microcapsule consisting in:

• a single core consisting in or comprising an oxidizable active (OA) under solid form, and

• a single water insoluble coating obtained from an encapsulating agent (EA), said coating surrounding said core.

By « single core » is meant a core forming a single and continuous volume inside said microcapsule.

By "single coating" is meant that said single core is surrounded by a single wall separating said core from the outside.

In an advantageous embodiment, the present invention relates to a microcapsule, wherein said oxidizable agent does not belong to carotenoids.

In an advantageous embodiment, the present invention relates to a microcapsule wherein the totality of said OA is found in said core.

In an advantageous embodiment, the present invention relates to a microcapsule consisting in or containing:

• a core consisting in or comprising an oxidizable active (OA), and

• a water insoluble coating obtained from an encapsulating agent (EA), said coating surrounding said core,

providing said microcapsule is placed in an external medium that do not comprise said OA.

In an advantageous embodiment, the present invention relates to a microcapsule consisting in or containing:

· a core consisting in or comprising an oxidizable active (OA), and

• a water insoluble coating obtained from an encapsulating agent (EA), said coating surrounding said core,

providing said microcapsule is placed in an external medium that do not comprise vitamin C or a chemical derivative of vitamin C.

In an advantageous embodiment, the present invention relates to a microcapsule comprising less than 10%, in particular less than 6%, in weight of water.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said EA is water soluble.

By "water soluble EA" is meant an EA that is sufficiently soluble in water to form a clear solution to the naked eye at a concentration of 5% in weight in water at 25°C.

By "water insoluble EA" is meant an EA that is sufficiently insoluble in water to form a turbid solution to the naked eye at a concentration of 1 to 5% in weight in water at 25°C.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said EA is an agent, the water solubility of which is pH-dependent.

By "an agent, the water solubility of which is pH-dependent" is meant that there is at least one pH value for which said agent is water soluble and at least one pH value for which said agent is water insoluble.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said water insoluble coating results from the reaction of a water soluble EA with means for inducing water insolubility of said EA.

By "means for inducing water insolubility" is meant any means that modifie the chemical state of said water soluble EA, providing a species that is water insoluble in standard reference conditions of temperature and pressure corresponding to a temperature of 25°C and a pressure of lOOKPa.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said means for inducing water insolubility are an agent chemically reacting with said EA.

Said means react with said water soluble EA, providing a water insoluble species.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said means for inducing water insolubility are an acid, a base, or a buffer.

Said acid, base, of buffer brings the pH from a value for which said EA is water soluble to a value for which said EA is water insoluble.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said means for inducing water insolubility consist in the drying of said EA.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said water insoluble coating is made of a water insoluble EA.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said coating is such that, when said microcapsule is placed in an alimentary, cosmetically or pharmaceutically acceptable medium:

• said OA is not degraded by element(s) of said medium, and

• said element(s) of the medium is (are) not degraded by said OA.

By "OA not degraded by element(s)", it means that the OA is not oxidized or modified by oxidation, in presence of element(s) of said medium.

Said degradation can be measured by standard analytical method such as HPLC, for example HPLC ascorbic acid dosage when said OA is vitamin C.

By "element(s) of the medium is (are) not degraded by said OA", it means that the element(s) is (are) not directly degraded by said OA, or degraded by product(s) issued from oxidative reactions involving said OA.

The degradation of a given medium is measured according to criteria known by those skilled in the art.

For example, a medium containing iron salts preferably under Fe2+ salt, would lead to the formation in the medium of iron ascorbate detectable with its specific black color.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said coating is such that, when said microcapsule is placed in a fermented food composition, in particular in a fermented vegetal milk composition:

• said OA is not degraded by element(s) of said composition, and

• said element(s) of the composition is (are) not degraded by said OA,

provided said composition is not a fermented dairy food composition.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said coating is such that, when said microcapsule is placed in an unfermented food composition, in particular in an unfermented dairy or an unfermented vegetal milk composition:

• said OA is not degraded by element(s) of said composition, and

· said element(s) of the composition is (are) not degraded by said OA.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said coating is such that, when said microcapsule is placed in a alimentary, cosmetically or pharmaceutically acceptable medium comprising globular proteins, in particular a medium comprising or consisting in an unfermented dairy or an unfermented vegetal milk composition and a medium comprising or consisting in a fermented vegetal milk compositions:

• said OA is not degraded by element(s) of said medium, and

• said element(s) of the medium is (are) not degraded by said OA,

provided said medium do not consist in or comprise a fermented dairy food composition.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said coating is such that, when said microcapsule is placed in a alimentary, cosmetically or pharmaceutically acceptable medium comprising Ca2+ cations, in particular a medium comprising or consisting in an unfermented dairy or an unfermented vegetal milk composition and a medium comprising or consisting in a fermented vegetal milk compositions:

• said OA is not degraded by element(s) of said medium, and

• said element(s) of the medium is (are) not degraded by said OA,

provided said medium do not consist in or comprise a fermented dairy food composition.

In an advantageous embodiment, the present invention relates to a microcapsule wherein the mass of said coating is within the range from 3 to 50%, preferably from 4 to 12%, more preferably from 5 to 8%, of the total mass of said microcapsule.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said microcapsule size is in range from Ι μιη to 3mm, preferably from 20 to 500μιη, more preferably from 50 to 200 μιη.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said OA is in a crystalline state.

By "crystalline state" is meant a state wherein OA molecules are arranged in an orderly, repeating pattern.

Examples of OA in a crystalline state are commercially available crystallized vitamins, such as crystallized vitamin C.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said core consists in or comprises an OA in a crystalline state and at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents.

Drying agents are for example starch, maltodextrin, proteins in particular casemates, gelatin, vegetable proteins in particular soya, wheat and pea proteins, gums in particular acacia gum as well known by those skilled in the art.

Examples of antioxidant agents are sodium ascorbate, ascorbyl palmitate, vitamin E, and tocopherol acetate.

Filmogen agents are for example proteins in particular caseinate, gums, cellulose derivatives as well known by those skilled in the art.

Examples of emulsifying agents are lecithin, proteins, hydrolyzed proteins, modified starch as well known by those skilled in the art.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said OA is in an amorphous state.

By "amorphous state" is meant a state wherein OA molecules are not arranged in an orderly, repeating pattern.

Compounds in an amorphous state are for instance described in Hancock et al. Journal of Pharmaceutical Sciences 1997, 86(1), pages 1-12.

Examples of OA in an amorphous state are OA amorphous solids obtained by spray-drying, under condition known by those skilled in the art: spray drying is known to produce predominately amorphous material from a homogenous solution, due to the almost instantaneous transition between liquid and solid phases.

It is noted that a microcapsule of the invention, wherein said OA is optionally in a crystalline or an amorphous state, can let small molecules such as protons and water pass through its coating when said microcapsule is placed in water or in an aqueous medium.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said OA is water soluble.

When water from an external medium consisting in water or an aqueous medium passes through said coating in an amount enough to dissolve said water soluble OA, a microcapsule consisting in or containing a aqueous solution of said OA and said water insoluble coating is obtained. Such a microcapsule allows a better bioavailability compared to particles where said OA is a solid form, as said water soluble OA is already dissolved in water.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said core consists in or comprises an OA in an amorphous state and at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said core consists in or comprises an OA and water, the core being a solution or a liquid suspension of said OA in water.

In an advantageous embodiment, the present invention relates to a microcapsule consisting in or containing:

• a core consisting in or comprising an OA, water and at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents, the core being a solution or a liquid suspension of said OA and said at least one additional elements in water, and

• an insoluble coating of a EA, said coating surrounding said core.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said water soluble EA is selected from alginates of monovalent cations, in particular Na+ alginates and K+ alginates.

Alginates enable said OA not to be released in some external media but to be released from said microcapsules only into a specific medium, such as in the gastrointestinal tract, wherein release of said OA is desired, in a controlled manner.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said means for inducing water insolubility are a salt wherein the cation is a divalent metallic cation, in particular Ca2+ or Mg2+, said salt being in particular CaCl2 or MgCl2.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said water insoluble coating is selected from alginates of divalent cations, in particular Ca2+ alginates and Mg2+ alginates.

In an advantageous embodiment, the present invention relates to a microcapsule according to anyone of claims 2 to 7, wherein said EA is water soluble and selected from alginates of monovalent cations, in particular Na+ alginates and K+ alginates, and wherein said means for inducing water insolubility are a salt wherein the cation is a divalent metallic cation, in particular Ca2+ or Mg2+, said salt being in particular CaCl2 or MgCl2.

In an advantageous embodiment, the present invention relates to a microcapsule wherein no divalent ion, in particular no Ca2+, is present in said core.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said EA is a resin, the water solubility of which is pH-dependent, in particular Lac gum.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said EA is a resin that is water soluble in basic conditions and water insoluble in acidic conditions, in particular shellac gum.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said EA is a resin that is soluble in an organic solvent, in particular in ethanol.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said means for inducing water insolubility are an acid, in particular an ascorbic acid.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said EA is water insoluble and selected from cellulose polymers, in particular ethylcellulose.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said EA is a cellulose polymer that is soluble in an organic solvent, in particular in ethanol.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said OA is selected from the group comprising vitamin C, vitamin B5, vitamin B6, vitamin B8, vitamin B9, vitamin A, vitamin D3, vitamin K and vitamin E.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said OA is vitamin C, in particular natural vitamin C, synthetic vitamin C, or salts of L-ascorbic acid, more particularly sodium L-ascorbate, calcium L-ascorbate and iron L-ascorbate.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said OA comprises vitamin C, said OA being in particular a fruit juice comprising vitamin C, in particular orange juice, kiwi juice, cranberry juice or acerola juice, said fruit juice being optionally concentrated or dried.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said OA is vitamin C or comprises vitamin C and wherein said EA is water soluble and selected from alginates of monovalent cations, in particular Na+ alginates and K+ alginates.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said OA is vitamin C or comprised vitamin C, wherein said EA is water soluble and selected from alginates of monovalent cations, in particular Na+ alginates and K+ alginates, and wherein said means for inducing water insolubility are a salt wherein the cation is a divalent metallic cation, in particular Ca2+ or Mg2+, said salt being in particular CaCl2 or MgCl2.

In an advantageous embodiment, the present invention relates to a microcapsule wherein said OA is selected from the group comprising dihydroxyacetone (DHA), enriched in omega 3 or omega 6 oil, and oxidizable enzymes, in particular superoxydismutase (SOD).

In another aspect, the present invention relates to a process of preparation of microcapsules described above, comprising the following steps:

o spray-drying a liquid mixture consisting in or comprising:

• said OA;

• optionally said EA;

· optionally at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents;

to obtain particles consisting in said OA, or particles comprising said OA, and said EA and/or at least one additional element,

o spraying on said particles an insoluble EA or means for inducing water insolubility of EA comprised in said particle, to obtain microcapsules with a water insoluble coating, said water insoluble coating surrounding a core consisting in said OA, or comprising said OA, and said EA and/or at least one additional element.

It is noted that said OA is, in said obtained microcapsule, predominantly in an amorphous state as spray drying is known to produce predominantly amorphous material from a homogenous solution, due to the almost instantaneous transition between liquid and solid phases.

The obtained microcapsules comprising said OA predominantly in an amorphous state have typically a size comprised from 1 μι ίο ΙΟΟΟμιη, preferably from 20μι ίο 500 μιη, and more preferably from 50 to 200 μιη.

The present invention also relates to a process of preparation of microcapsules according to anyone of claims 1 to 10, comprising the following steps:

o spray-drying a liquid mixture consisting in or comprising:

• said OA;

• optionally said EA;

• optionally at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents;

to obtain particles consisting in said OA, or particles comprising said OA, and said EA and/or at least one additional element, the outer part of said particles being in a solid form,

o spraying on said particles an insoluble EA or means for inducing water insolubility of EA comprised in said particle, to obtain microcapsules with a water insoluble coating, said water insoluble coating surrounding a core consisting in said OA, or comprising said OA, and said EA and/or at least one additional element,

with the proviso that:

- said core does not consist in or comprise a metal oxide, and

- said coating does not comprise a disintegrant, in particular sodium starch glycolate.

In an advantageous embodiment, the present invention relates to a process of preparation of microcapsules described above, comprising the following steps:

o spray-drying a liquid mixture consisting in or comprising:

• said OA;

• optionally said EA;

· optionally at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents;

to obtain particles consisting in said OA in an amorphous state, or particles comprising said OA in an amorphous state, and said EA and/or at least one additional element,

o spraying on said particles an insoluble EA or means for inducing water insolubility of EA comprised in said particle, to obtain microcapsules with a water insoluble coating, said water insoluble coating surrounding a core consisting in said OA in an amorphous state, or comprising said OA in an amorphous state, and said EA and/or at least one additional element.

In an advantageous embodiment, the present invention relates to a process comprising, after said spray-drying and spraying steps, a step of drying said microcapsules to obtain dried microcapsules.

In an advantageous embodiment, the present invention relates to a process wherein said spray-drying step is done in a spray-dryer and said spraying step and drying step are done in a coating device by spray, in particular a coating device by spray comprising a fluidized bed.

Examples of spray-dryer wherein the spray-drying step can be performed are single effect spray-drying towers, toll form spray-drying towers, belt dryer and multiple effect spray-drying towers with internal or external fluid bed.

Examples of coating device by spray wherein the spraying step can be performed are fluidized beds, top spray, tangential spray, bottom spray or wurster devices, batch process devices or continuous devices as horizontal fluid bed or multicellular fluid bed; these devices being as described in Vandamme et al Microencapsulation; Tec & Doc; 2007; Chapter 10.

In an advantageous embodiment, the present invention relates to a process wherein said spray-drying step, spraying step and drying step are done in the same spray-dryer.

Interestingly, the Inventors have found that the microcapsules, obtained by a process wherein said spray-drying step, spraying step and drying step are done in the same spray-dryer, surprisingly protect said OA from oxidation by a given alimentary, cosmetically or pharmaceutically acceptable medium in which said microcapsules are placed, and said medium from said OA.

Examples of spray-dryer wherein the spray-drying step and the spraying step can be performed are single effect spray-drying towers, toll form spray-drying towers, belt dryer and multiple effect spray-drying towers with internal or external fluid bed.

In an advantageous embodiment, the present invention relates to a process of preparation of microcapsules described above, comprising the following steps:

o spray-drying a liquid mixture consisting in or comprising:

• said OA;

• optionally said EA;

• optionally at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents;

to obtain particles consisting in said OA in an amorphous state, or particles comprising said OA in an amorphous state, and said EA and/or at least one additional element,

o spraying on said particles an insoluble EA or means for inducing water insolubility of

EA comprised in said particle, to obtain microcapsules with a water insoluble coating, said water insoluble coating surrounding a core consisting in said OA in an amorphous state, or comprising said OA in an amorphous state, and said EA and/or at least one additional element,

o drying said microcapsules to obtain dried microcapsules,

said spray-drying step, spraying step and drying step being done in the same spray-dryer.

In an advantageous embodiment, the present invention relates to a process wherein said means for inducing water insolubility are an agent chemically reacting with said EA.

In an advantageous embodiment, the present invention relates to a process wherein said means for inducing water insolubility are an acid, a base, or a buffer.

In an advantageous embodiment, the present invention relates to a process comprising the following steps:

o spray-drying a liquid mixture consisting in or comprising:

• said OA;

· optionally at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents;

to obtain particles consisting in said OA, or particles comprising said OA and said at least one additional element,

o spraying on said particles a water insoluble EA, to obtain microcapsules with a water insoluble coating, said water insoluble coating surrounding a core consisting in said OA, or comprising said OA and said at least one additional element.

In an advantageous embodiment, the present invention relates to a process comprising the following steps:

o spray-drying a liquid mixture consisting in or comprising:

• said OA;

• a water soluble EA;

• optionally at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents;

to obtain particles comprising said OA, said EA and optionally said at least one additional element,

o spraying on said particles means for inducing water insolubility of EA comprised in said particle, to obtain microcapsules with a water insoluble coating, said water insoluble coating surrounding a core comprising said OA, said EA and optionally at least one additional element.

Interestingly, the Inventors have found that the fact of inducing water insolubility of

EA by spraying said means, in particular in aqueous solution, on solid dried particles (comprising said OA and said EA) obtained by spray-drying, surprisingly forms a protective coating that has the ability to protect said OA from oxidation by a given alimentary, cosmetically or pharmaceutically acceptable medium in which said microcapsules are placed, and said medium from said OA.

Said process of the invention, wherein water insolubility of EA is induced by spraying means on solid dried particles is a dry spray-drying process with respect to said particles, which are dried before said spraying.

In an advantageous embodiment, the present invention relates to a process comprising the following steps:

o spray-drying a liquid mixture consisting in or comprising:

• said OA;

• alginate of monovalent cation, in particular Na+ alginate and K+ alginate;

• optionally at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents;

to obtain particles comprising said OA, said alginate and optionally said at least one additional element,

o spraying on said particles means for inducing water insolubility of alginate comprised in said particle, to obtain microcapsules with a water insoluble coating, said water insoluble coating surrounding a core comprising said OA, said EA and optionally at least one additional element.

In an advantageous embodiment, the present invention relates to a process comprising the following steps:

o spray-drying a liquid mixture consisting in or comprising:

• said OA;

• alginate of monovalent cation, in particular Na+ alginate and K+ alginate;

• optionally at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents;

to obtain particles comprising said OA, said alginate and optionally said at least one additional element,

o spraying on said particles an aqueous solution of a salt wherein the cation is a divalent metallic cation, in particular Ca2+ or Mg2+, said salt being in particular CaCl2 or MgCl2, to obtain microcapsules with a water insoluble coating, said water insoluble coating surrounding a core comprising said OA, said EA and optionally at least one additional element;

o drying said microcapsules to obtain dried microcapsules.

In an advantageous embodiment, the present invention relates to a process wherein said liquid mixture is a homogenous aqueous solution.

The liquid mixture is a homogenous aqueous solution when said OA, said EA and, provided an additional element is present in said mixture, said additional element are water soluble.

When the liquid mixture is a homogenous aqueous solution, the size of the obtained microcapsules are driven by the parameters of spray-drying, and not by the characteristics of said water soluble OA.

The microcapsules obtained have typically a size comprised from 1 μιη to ΙΟΟΟμιη, preferably from 20 μιη to 500 μιη, and more preferably from 50 to 200 μιη.

In an advantageous embodiment, the present invention relates to a process wherein said liquid mixture is a solid-in-liquid suspension or an emulsion.

In an advantageous embodiment, the present invention relates to a process wherein said liquid mixture is a homogenous aqueous solution consisting in or comprising said OA.

In an advantageous embodiment, the present invention relates to a process wherein said liquid mixture is a homogenous aqueous solution consisting in or comprising said OA and at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents.

In an advantageous embodiment, the present invention relates to a process wherein said liquid mixture is a homogenous aqueous solution consisting in or comprising said OA and said water soluble EA.

In an advantageous embodiment, the present invention relates to a process wherein said liquid mixture is a homogenous aqueous solution consisting in or comprising said OA, said water soluble EA, and at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents.

In another aspect, the present invention relates to a process comprising a step of spraying on particles consisting in said OA, or particles comprising said OA, and said EA and/or at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents, an insoluble EA or means for inducing water insolubility of EA comprised in said particle, to obtain microcapsules with a water insoluble coating, said water insoluble coating surrounding a core consisting in said OA, or comprising said OA, and said EA and/or at least one additional element.

In an advantageous embodiment, the present invention relates to a process comprising, after said spraying step, a step of drying said microcapsules to obtain dried microcapsules.

In an advantageous embodiment, the present invention relates to a process wherein said means for inducing water insolubility are an agent chemically reacting with said EA.

In an advantageous embodiment, the present invention relates to a process wherein said means for inducing water insolubility are an acid, a base, or a buffer.

In an advantageous embodiment, the present invention relates to a process comprising a step of spraying on particles consisting in said OA, or particles comprising said OA and at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents, a water insoluble coating to obtain microcapsules with a water insoluble coating, said water insoluble coating surrounding a core consisting in said OA, or comprising said OA, and said at least one additional element.

In an advantageous embodiment, the present invention relates to a process comprising a step of spraying in a device on particles comprising:

• said OA,

· a water soluble EA, and

• optionally at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents,

means for inducing water insolubility of EA comprised in said particle, to obtain microcapsules with a water insoluble coating, said water insoluble coating surrounding a core comprising said OA, and said EA and/or at least one additional element.

Interestingly, the Inventors have found that the fact of inducing water insolubility of EA by spraying said means, in particular in aqueous solution, on solid dried particles (comprising said OA and said EA), for example obtained by spray-drying, surprisingly forms a protective coating that has the ability to protect said OA from oxidation by a given alimentary, cosmetically or pharmaceutically acceptable medium in which said microcapsules are placed, and said medium from said OA.

Examples of device wherein the spraying step can be performed are fluidized beds, top spray, tangential spray, bottom spray or wurster devices, batch process devices or continuous devices as horizontal fluid bed or multicellular fluid bed; these devices being as described in Vandamme et al Microencapsulation; Tec & Doc; 2007; Chapter 10.

Said process of the invention, wherein water insolubility of EA is induced by spraying means on solid dried particles is a dry spray-drying process with respect to said particles, which are dried before said spraying.

Two cases can be distinguished:

-the first one occurs when means for inducing water insolubility involves all the EA comprised in said particles; in this case, microcapsules with a core consisting in said OA, or comprising said OA, and optionally at least one additional element, are obtained;

- the second one occurs when means for inducing water insolubility involves only a part of the EA comprised in said particles, in particular EA present on or near the surface of said particles; in that case, microcapsules with a core comprising said OA, said EA and optionally at least one additional element, are obtained.

The nature of the means for inducing water insolubility, the mass of EA in respect of the total mass of said microcapsule, and the distribution of EA in said particles are factors that can lead to the first or the second case.

In an advantageous embodiment, the present invention relates to a process comprising a step of spraying on particles comprising:

· said OA,

• alginate of monovalent cation, in particular Na+ alginate and K+ alginate, and

• optionally at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents,

means for inducing water insolubility of alginate comprised in said particle, to obtain microcapsules with a water insoluble coating, said water insoluble coating surrounding a core comprising said OA, and said alginate and/or at least one additional element.

In an advantageous embodiment, the present invention relates to a process comprising a step of spraying on particles comprising:

• said OA,

• alginate of monovalent cation, in particular Na+ alginate and K+ alginate, and

• optionally at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents,

an aqueous solution of a salt wherein the cation is a divalent metallic cation, in particular Ca2+ or Mg2+, said salt being in particular CaCl2 or MgCl2, to obtain microcapsules with a water insoluble coating, said water insoluble coating surrounding a core comprising said OA, and said alginate and/or at least one additional element.

In an advantageous embodiment, the present invention relates to a process wherein said particles are obtained by coating said OA in a solid state with said water soluble EA and optionally at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents.

In an advantageous embodiment, the present invention relates to a process wherein said particles are obtained by coating said OA in a crystalline state with said water soluble EA and optionally at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents.

Thus, the microcapsules obtained after spraying on said particles means for inducing water insolubility of said EA comprise a core consisting in or comprising OA in a crystalline state.

It is noted that the size of microcapsules is driven by the size of OA particles in crystalline state.

For example, the size of microcapsules obtained from vitamin C particles having a size comprised from 20 to 200 μιη is comprised from 20 to 350 μιη.

In an advantageous embodiment, the present invention relates to a process wherein said particles are obtained by co-spraying a homogenous aqueous solution comprising:

• said water soluble EA,

• optionally at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents;

and said OA in a solid state.

By co-spraying is meant that said homogenous aqueous solution and said OA in a solid state are sprayed jointly in such a manner that the sprayed homogenous aqueous solution films the particles of OA in a solid state to give particles that are totally filmed by the EA.

In an advantageous embodiment, the present invention relates to a process wherein said particles are obtained by co-spraying a homogenous aqueous solution comprising:

• said water soluble EA,

• optionally at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents;

and said OA in a crystalline state.

Thus, the microcapsules obtained after spraying on said particles means for inducing water insolubility of said EA comprise a core consisting in or comprising OA in a crystalline state.

It is noted that the size of microcapsules is driven by the size of OA particles in crystalline state.

For example, the size of microcapsules obtained from vitamin C particles having a size comprised from 20 to 200 μιη is comprised from 20 to 350 μιη.

In an advantageous embodiment, the present invention relates to a process wherein said particles are obtained by co-spraying a homogenous aqueous solution comprising said water soluble EA and said OA in a solid state.

In an advantageous embodiment, the present invention relates to a process wherein said particles are obtained by co-spraying in a spray-dryer a homogenous aqueous solution comprising:

· said water soluble EA;

• at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents;

and said OA in a solid state.

In an advantageous embodiment, the present invention relates to a process wherein particles are obtained in a spray-dryer.

In an advantageous embodiment, the present invention relates to a process wherein said spraying of said means for inducing water insolubility of EA is performed in the spray-dryer used to obtain said particles.

Examples of spray-dryer wherein the spray-drying step and the spraying step can be performed are single effect spray-drying towers, toll form spray-drying towers, belt dryer and multiple effect spray-drying towers with internal or external fluid bed.

Interestingly, the Inventors have found that the microcapsules, obtained by a process wherein said spraying of said agent is performed in the same spray-dryer as the one used to obtain said particles, in a single step of obtaining particles by spray-drying and spraying them with said agent, surprisingly protect said OA from oxidation by a given alimentary, cosmetically or pharmaceutically acceptable medium in which said microcapsules are placed, and said medium from said OA.

In an advantageous embodiment, the present invention relates to a process comprising the following steps:

o co-spraying in a spray-dryer a homogenous aqueous solution comprising:

o said water soluble EA,

o optionally at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents;

and said OA in a crystalline state, to obtain particles comprising:

· said OA in a crystalline state,

• said water soluble EA,

• optionally at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents,

o spraying in a device on said particles means for inducing water insolubility of EA comprised in said particles, to obtain microcapsules with a water insoluble coating, said water insoluble coating surrounding a core comprising said OA in a crystalline state, and said EA and/or at least one additional element.

In an advantageous embodiment, the present invention relates to a process comprising the following steps:

o co-spraying in a spray-dryer a homogenous aqueous solution comprising:

o said water soluble EA,

o optionally at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents;

and said OA in a crystalline state, to obtain particles comprising:

• said OA in a crystalline state,

• said water soluble EA,

• optionally at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents,

o spraying in the same spray-dryer on said particles means for inducing water insolubility of EA comprised in said particles, to obtain microcapsules with a water insoluble coating, said water insoluble coating surrounding a core comprising said OA in a crystalline state, and said EA and/or at least one additional element.

In an advantageous embodiment, the present invention relates to a process comprising the following steps:

o co-spraying in a spray-dryer a homogenous aqueous solution comprising:

• alginate of monovalent cation, in particular Na+ alginate and K+ alginate, and

• optionally at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents;

and said OA in a solid state, to obtain particles comprising:

• said OA,

• alginate of monovalent cation, in particular Na+ alginate and K+ alginate, and optionally at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents,

o spraying in a device on said particles an aqueous solution of a salt wherein the cation is a divalent metallic cation, in particular Ca2+ or Mg2+, said salt being in particular CaCl2 or MgCl2, to obtain microcapsules with a water insoluble coating, said water insoluble coating surrounding a core comprising said OA, and said alginate and/or at least one additional element,

o drying said microcapsules to obtain dried microcapsules.

In an advantageous embodiment, the present invention relates to a process comprising the following steps:

o co-spraying in a spray-dryer a homogenous aqueous solution comprising:

• alginate of monovalent cation, in particular Na+ alginate and K+ alginate, and

• optionally at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents;

and said OA in a solid state, to obtain particles comprising:

• said OA,

• alginate of monovalent cation, in particular Na+ alginate and K+ alginate, and optionally at least one additional element selected among drying agents, antioxidant agents, filmogen agents and emulsifying agents,

o spraying in the same spray-dryer on said particles an aqueous solution of a salt wherein the cation is a divalent metallic cation, in particular Ca2+ or Mg2+, said salt being in particular CaCl2 or MgCl2, to obtain microcapsules with a water insoluble coating, said water insoluble coating surrounding a core comprising said OA, and said alginate and/or at least one additional element,

o drying said microcapsules to obtain dried microcapsules.

In another aspect, the present invention relates to a food composition comprising microcapsules described above, provided said food composition is not a fermented dairy food composition.

In an advantageous embodiment, the present invention relates to a food composition comprising microcapsules described above, provided said food composition is not a fermented dairy food composition and said food composition do not comprise vitamin C or a chemical derivative of vitamin C.

In an advantageous embodiment, the present invention relates to a food composition comprising unfermented dairy products.

In an advantageous embodiment, the present invention relates to a food composition comprising a vegetal milk, in particular almond, coconut, rice and soy milk, said composition being unfermented or fermented.

In an advantageous embodiment, the present invention relates to a food composition comprising one or more fruits in addition of said microcapsules.

In an advantageous embodiment, the present invention relates to a food composition wherein said food composition is a fruit juice composition.

In an advantageous embodiment, the present invention relates to a food composition comprising one or more vegetables in addition of said microcapsules.

In an advantageous embodiment, the present invention relates to a food composition comprising:

• said microcapsules,

• water,

• one or more sugar and/or sweetener

• flavoring(s).

In another aspect, the present invention relates to a cosmetic composition comprising microcapsules described above.

In another aspect, the present invention relates to a pharmaceutical composition comprising microcapsules described above.

In another aspect, the present invention relates to the use of microcapsules described above for the preparation of a food composition.

In another aspect, the present invention relates to the use of microcapsules described above for the preparation of a cosmetic composition.

In another aspect, the present invention relates to the use of microcapsules described above for the preparation of a pharmaceutical composition.

DESCRIPTION OF THE FIGURES

Figure 1 presents a process wherein vitamin C particles in a crystalline form (1) are coated in a fluid bed (2) with an aqueous alginate solution (3) sprayed on said particles. Obtained particles (7) are then placed (5) in the same or another fluid bed (2bis). Alginate solution or acid or base or buffer or salt solution (4) is then sprayed on the particles (7) or the said particles are solely dried. Microcapsules (8) are recovered (6).

Figure 2 presents a process wherein, alginate and optionally addition elements are solubilized in water, with solubilized or fruit juice vitamin C: solution (Ibis), or with crystalline vitamine C: suspension (IBis) and then sprayed in the spray-dryer (9). Either the obtained particles (7) are then transferred (10) in a fluid bed (2bis) and an alginate solution or acid or base or buffer or salt solution (4) is sprayed on said particles (7), or an alginate solution or acid or base or buffer solution (4) is in parallel sprayed in the same said spray dryer (9), and then optionally dried. Microcapsules (8) are recovered (6).

Figures 3, 4 and 5 present scanning electron microscope (SEM) analyses of microcapsules obtained by the process respectively described in example 4, 2 and 3.

Figure 6 present scanning electron microscope (SEM) analysis of a microcapsule obtained by the process described in example 1, which was fractured prior to said analysis.

Said SEM analyses were performed with a Quanta200, ESEM FEG type microscope (Scanning Electron Microscopes, Field emission gun), at a water vapor pressure of 1.2mbar, a voltage of 20kV and a current density of 4 (on a scale ranging from 0 to 7).

Figure 7A presents the vitamin C monitoring on a microcapsule obtained by the process described in example 4.

Said microcapsules were packed in heat-sealed aluminum bags, stored at 4°C or 20°C and monitored over time, over a period of 3 months. The results show that there is no degradation of vitamine C content after 3 months of storage. Vitamin C monitoring was performed according to standard NF 14130 (by HPLC).

Figure 7B presents the vitamin C monitoring on a microcapsule obtained by the process described in example 4.

Said microcapsules were packed in heat-sealed aluminum bags, stored at 4°C or 20°C and monitored over time, over a period of 6 months. The results show that there is no degradation of vitamine C content after 6 months of storage. Vitamin C monitoring was performed according to standard NF 14130 (by HPLC).

Figure 8 presents the following of the size of microcapsule obtained by the process described in example 4 over time, when said microcapsules are placed in water at room temperature. Size is expressed in D(v; 0.5) in microns and is measured using a laser particle sizer Malvern Instrument, MSS Type, model MasterSizer, D(v; 0.5) being the mean particle size of the obtained microcapsule size distribution.

The present invention is further illustrated by the following examples.

EXAMPLES

Example 1: Microcapsules containing vitamin C

3.3 kg of crystalline vitamin C were fluidized in a fluid bed (WSG5 GLATT), inlet air temperature is 60°C.

2.9 kg of a 5 % solution of sodium alginate in dry matter, containing 10 g of ascorbyl palmitate were sprayed on the fluidized particles with a bifluid nozzle (spraying system SS 2050), on a top-spray position, as well known by those skilled in the art (in particular Vandamme et al Microencapsulation; Tec & Doc; 2007), and then dried. Solid particles are obtained.

Another 1.1 Kg of a 5 % solution of sodium alginate in dry matter was then spray dried on the fluidized particles. A final drying step of 30 mn was then processed at a maximum temperature of 50°C on the microcapsules.

The final microcapsules had a moisture content of 1.1% (infrared measurement). Particle size distribution was below 300 μιη (mean particle size measured by light diffraction on Malvern sizer) and bulk density was of 850 g/1.

Example 2 : Microcapsules containing vitamin C

A solution was prepared with 7.8kg of crystalline vitamin C in 31.2 kg of water at room temperature. 3.78kg of modified starch, 0.5 kg of carboxymethylcellulose and 0.8 kg of alginate were added to this preparation. The preparation was then homogenized at a pressure of 200bars. The homogenized preparation was then dried in a single stage dryer (Minor production tower, GEA-NIRO) with a rotary atomizer, with an inlet temperature of 150°C and outlet temperature of 85°C. Solid particles are obtained.

4.6 kg of a calcium chloride solution at 5% dry matter was then sprayed on the fluidized particles on a fluidized bed (WSG5, GLATT) as well known by those skilled in the art.

The final microcapsules had an average size of 210 μιη (mean particle size measured by light diffraction on Malvern sizer), a moisture content of 2.3 % and a bulk density of 650 g/1.

Example 3 : Microcapsules containing vitamin C from acerola juice

2.6 kg of acerola fruit juice, with a vitamin C content of 20.9g /100ml, was mixed with 0.6 kg of starch, 0.08kg of carboxy methyl cellulose, 0.10kg of alginate and 7.8 kg of water.

The preparation was homogenized at 200 bars.

The homogenized preparation was then dried in a single stage dryer (Minor production tower, GEA-NIRO) with a rotary atomizer, with an inlet temperature of 125°C and outlet temperature of 90°C. Solid particles are obtained.

0.6 kg of a calcium chloride solution at 5% dry matter was then sprayed on the fluidized particles on a fluidized bed (WSG5, GLATT) as well known by those skilled in the art.

The final microcapsules had an average size of 80μιη (mean particle size measured by light diffraction on Malvern sizer), a moisture content of 5 % and a bulk density of 630 g/1.

Example 4 : Microcapsules containing vitamin C

3.3 kg of crystalline vitamin C, were fluidized in a fluid bed (WSG5 GLATT), inlet air temperature is 60°C.

2.9 kg of a 5 % solution of sodium alginate in dry matter, containing 10 g of ascorbyl palmitate were sprayed on the fluidized particles with a bifluid nozzle (spraying system SS 2050), on a top-spray position, as well known by those skilled in the art (in particular Vandamme et al Microencapsulation; Tec & Doc; 2007). Solid particles are obtained.

0.8 Kg of a calcium chloride solution, 5% dry matter was then spray dried on the fluidized particles. The final microcapsules had a moisture content of 2.8% (infrared measurement). Particle size distribution was below 300 μιη (mean particle size measured by light diffraction on Malvern sizer) and bulk density was of 800 g/1.

Example 5 : Microcapsules containing vitamin C

A solution was prepared with 7.8kg of crystalline vitamin C in 31.2 kg of water at room temperature. 3.78kg of modified starch, 0.5 kg of carboxymethylcellulose and 0.8 kg of alginate were added to this preparation. The preparation was then homogenized at a pressure of 200bars. 4.6 kg of a calcium chloride solution at 5% dry matter was prepared. The homogenized preparation was then sprayed in a single stage dryer (Minor production tower, GEA-NIRO) with a rotary atomizer, and the calcium chloride solution was also sprayed in the same time in the chamber of the same dryer. Drying step was made with an inlet temperature of 150°C and outlet temperature of 75°C.

The final microcapsules had an average size of 80 μιη (mean particle size measured by light diffraction on Malvern sizer), a moisture content of 6.0 % and a bulk density of 600 g/1.

Example 6 : Microcapsules containing omega 3 enriched oil

1.3 kg of omega 3 enriched oil was mixed with 3.8kg of modified starch, 0.7kg of carboxymethylcellulose, 0.8kg of alginate and 11.8kg of water.

The preparation was homogenized at 200 bars.

The homogenized preparation was then dried in a single stage dryer (Minor production tower, GEA-NIRO) with a rotary atomizer, with an inlet temperature of 150°C and outlet temperature of 80°C. Particles with a solid outer part are obtained.

4.1 kg of a calcium chloride solution at 5% dry matter was then sprayed on the fluidized particles on a fluidized bed (WSG5, GLATT) as well known by those skilled in the art.

The final microcapsules had an average size of 80μιη (mean particle size measured by light diffraction on Malvern sizer), a moisture content of 3.2 % and a bulk density of 470 g/1.

Example 7 : Microcapsules containing vitamin C coated with ethylcellulose

2.47 kg of crystalline vitamin C were fluidized in a fluid bed (WSG5, GLATT). Inlet temperature did not exceed 40°C.

2.47 kg of ethylcellulose were prepared in ethanol at 10% dry matter and sprayed using a bi-fluid nozzle (spraying system SS 2050), on a top spray position on the fluidized crystalline vitamin.

After the coating, the microcapsules were dried in the fluidized bed chamber for 10 mn.

The final microcapsules had a moisture content of 1.1% (infrared moisture measurement, 105°C) and a particle size distribution of 130 μιη (mean particle size measured by light diffraction on Malvern sizer).

Example 8 : Microcapsules containing SOD

3.3 kg of freeze dried superoxydismutase enzyme (SOD) were fluidized in a fluid bed (WSG5, GLATT). Inlet temperature was 60°C.

2.9 kg of a 5 % solution of sodium alginate in dry matter, containing 10 g of ascorbyl palmitate were sprayed on the fluidized particles with a bifluid nozzle (spraying system SS 2050), on a top-spray position, as well known by those skilled in the art (in particular Vandamme et al Microencapsulation; Tec & Doc; 2007). Solid particles are obtained.

0.8 Kg of a calcium chloride solution, 5% dry matter was then spray dried on the fluidized particles.

The final microcapsules had a moisture content of 1.3 %. Particle size distribution was below 300 μιη (mean particle size measured by light diffraction on Malvern sizer) and bulk density was of 410 g/1.

Example 9 : Microcapsules containing SOD coated with Lac gum

500g of freeze-dried of superoxydismutase enzyme (SOD) were weighted and put into a fluid bed (GPCG1, GLATT) and fluidized. 516 g of Lac gum (ie: 500 g of Dry Lac gum) were dissolved at 20% dry matter and sprayed on the fluidized SOD. Process temperature of the powder did not exceed 36°C. Final product had a moisture content of 2.1% and an average particle size mean of 370μιη (Median diameter Dv(0.5) measured by laser particle sizer Malvern)

Analyses of SOD activity were made in water solution at pH 2.9 and 7.0.

No SOD activity was observed at pH 2.9 although more than 95 % of SOD activity is recovered at pH 7.0.

Example 10 : Microcapsules containing ferrous ascorbate

1.2 kg of ferrous ascorbate were weighted and put into a fluid bed (GPCG1, GLATT), inlet air temperature is 80°C.

1.1 kg of a 5 % solution of sodium alginate in dry matter were sprayed on the fluidized particles with a bifluid nozzle, on a top-spray position. Solid particles are obtained.

0.3 Kg of a calcium chloride solution, 5% dry matter was then spray dried on the fluidized particles.

The final microcapsules had a moisture content of 6 %. Particle size distribution was below 300 μιη (mean particle size measured by light diffraction on Malvern sizer) and bulk density was of 420 g/1.

Example 11 : Microcapsules containing DHA

500g of crystalline Dihydroxyacetone (DHA) were weighted and put into a fluid bed (GPCG1, GLATT) and fluidized. 125g of Lac gum were dissolved at 24% dry matter and sprayed on the fluidized DHA.

The microcapsules obtained had a moisture content of 4.1%, and a particle size distribution of 790 μιη (mean diameter, measured by laser diffraction on Malvern sizer)

Evaluation of coloration was made in water at pH 4.0 and 7.0.

No coloration occurred after 1H at pH 4.0, although in water at pH 7.0 an orange coloration appeared in the first 15mn and became brownish after 1H showing the protective effect of the microcapsule of the invention in low pH conditions.