NL2002049C - ENCAPSULATE USING A DOUBLE SUSPENSION. - Google Patents

Description

P85862NL00

Title: Encapsulate using a double suspension

The invention relates to a method for preparing edible particles, to a double suspension comprising edible particles, to edible particles, and to a foodstuff comprising edible particles.

In this description, particles with a hierarchical structure are particles that are composed of different substances, in particular particles with therein one or more compartments of a first substance that are surrounded by a second substance.

Particles with a hierarchical structure have various applications. For example, particles of an active substance, such as a drug or a nutrient, may be surrounded by a protective layer (such as by encapsulation) to protect the active substance against undesired effects of the environment and / or to protect the environment against the active substance. Examples of this are to prevent oxidation, chemical degradation or controlled release on the one hand, WO 01/60339 describes a method for the preparation of microencapsulated colloidal systems, for pharmaceutical applications in which an emulsion of a first phase comprising a crosslinkable polymer is formed in a second phase comprising a second polymer. Furthermore, a colloidal system is suspended in the first phase. The preparation of edible food particles using an edible cross-linkable polymer and an edible second polymer is not described.

EP-A 0 797 925 describes the encapsulation of particles in an uncrosslinked protein layer using a demixing protein - polysaccharide two-phase system. The particles are separated from the phase-separated protein phase by sagging or centrifuging. There is no mention of crosslinking the protein first. (Partly) as a result of this, the protein layer around the particles will be relatively thin.

It is an object of the invention to provide a new method for preparing edible particles, in particular particles with a hierarchical structure, for example particles with a shell-around-core morphology.

It is a further object of the invention to provide a new method for preparing particles with a hierarchical structure in which the particles are composed of two or more solids, of particles composed of at least one solid and a liquid , in particular an at least not fully water-soluble substance, and / or wherein the particles comprise a gaseous phase surrounded by a solid phase.

It is a further object of the invention to provide edible particles with a stabilized particle size, in particular such particles comprising a gas phase and a solid phase, such as foam particles.

One or more other objects which can be achieved by means of the invention follow from the rest of the description and / or claims.

It has now been found that it is possible to prepare particles with a hierarchical structure from a certain type of double suspension.

The invention therefore relates to a method for preparing edible particles comprising at least a first phase, which first phase surrounds at least substantially a second phase, which second phase is solid, liquid or gaseous and / or comprises a micro-organism, the method comprising suspending an edible solid material, liquid, gas and / or microorganism (for said second phase) in a liquid comprising a first edible polymer and a second edible polymer and forming a double suspension, wherein at least a polymer (polymer A) of said first and second polymer is present at least substantially in the suspended phase of the double suspension 3 and at least one other polymer (polymer B) of said first and second polymer is present at least substantially in the continuous phase.

Usually, c) polymer A is then crosslinked or otherwise fixed.

In a particular embodiment, first a liquid mixture is prepared from the first and the second polymer and then the second phase is added to the liquid mixture prior to the formation of the double suspension, or during the formation of the double suspension. It is also possible to add the second phase after the double suspension 10 has been formed from the liquid mixture. An advantage of first forming a mixture of the first and the second polymer before the second phase is added is a potentially reduced long exposure to process conditions (such as temperature) that may be detrimental to the second phase. Hereby it is considered possible to realize a quality advantage, such as in better maintenance of activity of an active ingredient, a reduced oxidation, etc. Such a method is particularly preferably applied if a second phase is selected from the group of enzymes, microorganisms, probiotics and, oxidation sensitive substances, such as fish oils.

In another particular embodiment, the preparation of edible particles comprising at least a first phase which comprises at least substantially a second phase of the first phase, which second phase is solid, liquid or gaseous and / or comprises a microorganism, the method comprising a suspending an edible solid, liquid, gas, and / or microorganism (for said second phase) in a first solution comprising a first edible polymer; and b) suspending the suspension prepared under a) in a second solution comprising a second edible polymer, forming a double suspension, wherein at least one polymer (polymer A) of said first and second polymer is present at least substantially is in the suspended phase of the double emulsion and at least one other polymer (polymer B) of said first and second polymer is at least substantially present in the continuous phase.

Usually, c) polymer A is then crosslinked or otherwise fixed.

Surprisingly, it has been found possible by means of the invention to obtain a double suspension in which a suspension is present which comprises the first and the second phase, which in turn is surrounded by a third phase (the continuous phase).

The preparation of the double suspension is based on the principle that solutions of two or more types of polymers (A and B, respectively) can separate if they are present in a certain concentration. This results in at least two phases, with polymer A mainly ending up in one phase and polymer B in the other. In this way a suspension can arise in which one phase is dispersed as small drops in the other phase. The continuous and the dispersed phase herein contain at least substantially the same liquid, the driving force behind the maintenance of the emulsion being the polymers. In the case that water is the solvent, this is referred to as a water-in-water emulsion.

To obtain particles with at least one solid first phase, the polymer in the suspended phase (polymer A) is usually crosslinked or otherwise fixed, forming the first (solid) phase that at least substantially surrounds the second phase. The fixing preferably takes place at least substantially after the second phase (at least substantially) is surrounded by the first phase. This can be advantageous for one or more properties of the particles, in particular of the first phase (the enveloping phase).

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By "edible" herein is meant in particular "suitable for human consumption", more particularly suitable for use in a food, such as for example a dairy product or a fruit drink.

By "solid" herein is meant in particular that a substance at room temperature (20 ° C) under atmospheric pressure is essentially dimensionally stable, such as a substance in a solid aggregate state (a substance with a melting temperature above room temperature), a gel, an edible material , such as an herb, spice or dietary fiber, etc.

By "liquid" herein is meant in particular that a substance behaves as a liquid at room temperature (20 ° C) under atmospheric pressure, such as a substance in a liquid aggregation state (a substance with a melting temperature below room temperature and a boiling temperature above room temperature, such as a vegetable or animal oil, for example fish oil, olive oil, linseed oil, etc.

By "gaseous" herein is meant in particular that a substance behaves as a gas at room temperature (20 ° C) under atmospheric pressure, such as a substance with a boiling temperature below room temperature, such as air, oxygen, CO2, nitrogen, and the like.

By "at least substantially" is generally meant more than 50% to a maximum of 100%, in particular at least 75%, more in particular at least 90%. By "at least substantially surrounded" is meant in particular: for 90% -100% of the surface, more in particular for at least 95%, such as at least 99% of the surface.

Figure 1 shows schematically a particle (prepared) according to the invention with a shell around nuclear morphology.

Figure 2 shows schematically a particle in which the first phase surrounds more than one compartment formed by the second phase.

Figure 3 shows a photograph of particles according to the invention.

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Examples of fixing are, in addition to crosslinking: precipitation, denaturing and gelation.

The fixing preferably comprises a cross-linking step. In cross-linking, essentially covalent bonds are preferably formed between two or more molecules of the polymer A in at least a part of the second phase.

A cross-linking can be performed using a cross-linking activator.

Possible cross-linking activators are polyvalent cations, in particular divalent cations, such as for example calcium, a pH change; and / or a change in ionic strength. The ionic strength can be changed by adjusting the salt concentration, for example by changing the KCl and / or NaCl concentration. A pH change as a crosslinking activator will, as a rule, be a pH reduction.

Cross-linking can be carried out in an extremely suitable manner during the spray-drying process, optionally in combination with the use of a cross-linking activator.

Preferably, use is made of a protein that has been fully or partially denatured or otherwise activated before spray drying. By activating the protein (or from another polymer to be cross-linked) is meant making available reactive groups - i.e., reactive amino acid residue groups, such as -SH groups, in the case of proteins - which can participate in the cross-linking reaction, in particular to a cross-linking by means of spray drying. The formation of microcapsules by spray drying of a double suspension, in particular a double suspension comprising a denatured protein, can be based, for example, in a manner known per se, for example as described in WO 08/060154 WO 07/136263 or US 30 5,601,760. The spray drying techniques 7 described in these publications are incorporated herein by reference. Spray drying of a double suspension according to the present invention has the advantage that a better envelope can be obtained from the second phase, in the sense that it is possible to provide an envelope that is thicker and / or better encloses the encapsulated phase. Also, depending on the selected conditions (such as by adjusting the concentration of dry substance that is sprayed or spray dried) it can be ensured that spray dried agglomerates of capsules, after dissolving in water, can fall apart into non-agglomerated protein capsules. This is an advantage when small particles are desired, for example to prevent settling or creaming in a liquid.

For encapsulating a second phase, in particular of a triglyceride oil, it is advantageous for the cross-linking to proceed gradually, which can be achieved by gradually changing the cross-linking conditions. This can be achieved, for example, by gradually adding a cross-linking activator, such as by gradually adding a polyvalent cation, or by gradually changing the pH. It is also possible to opt for the addition of a cross-linking activator that gradually changes the pH, for example by adding GDL (glucono-delta-lactone). As a result, the pH drops slowly to a value at which, in particular, a protein is cross-linked. The action of GDL is based on the slow hydrolysis of the lactone with the inclusion of 1 molecule of water per lactone group and the formation of a free protonated carboxyl group, which results in the pH reduction. It is, of course, possible to use another agent in which protons are released during its degradation (for example by hydrolysis).

Usually the particles are isolated, in particular by filtration, and / or optionally dried and / or added to another phase, preferably a food, in particular a food, including drinks.

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By surrounding the second phase with a first phase, in particular a fixed first phase, one or more effects can be achieved. For example, the first phase may serve to mask a possibly perceived unpleasant odor or taste (such as, for example, if the second phase comprises fish oil), to prevent the second phase from being prematurely absorbed, inactivated or degraded by the gastrointestinal tract (e.g. in the gastrointestinal tract) case of prebiotics, probiotics or microorganisms intended to effect an effect in the colon), for chemical and / or mechanical stabilization of the second phase against environmental influences (for example in the case of oxidizable substances such as vitamins or (unsaturated) oils; certain fragrances or flavors, gas bubbles, micro-organisms). It is also possible to realize a delayed digestion in the gastrointestinal tract, for example of an oil or fat encapsulated in a protein. A delayed digestion is for example desirable to postpone a feeling of hunger, which may be desirable for dietary reasons to prevent obesity or for a more gradual release of a food (ingredient), so that an improved (prolonged) effect can be obtained.

A method according to the invention is extremely suitable for the preparation, if desired, in a simple manner of particles with a core-shell morphology, such as capsules with a core (comprising the second phase) and a solid shell (comprising the first phase, which polymer A). Such a particle is shown schematically in Figure 1, in which the surrounding phase 1 encloses one second phase 2.

Particles with such a morphology can have one or more advantages over particles in which the content of the particles is distributed over a large number of compartments. For example, there is a clearly distinguishable core with easily controllable properties that may be different from those of the hairstyle. A particle with such a morphology can also consist of an internal phase to a greater extent. Furthermore, the release of the inner material can be better controlled or at least achieved differently. A (micro) capsule with a shell-around-core morphology will, for example, be able to burst under the influence of shear forces and thus release its contents in one go or at least substantially instantaneously. This can, for example, produce a special organoleptic effect if the second phase comprises a fragrance and / or flavor.

The average thickness of the shell (the first phase) can be chosen within wide limits, by choosing the nature and concentration of the polymers, solvent (s) for the polymers A and B and process conditions such as the degree of agitation (eg the stirring speed). The invention is very suitable for the preparation of particles with a shell of at least 0.1 μιη, as determined by means of microscopy. Preferably the thickness of the shell is at least 0.12 μιη, at least 0.15 μιη or at least 0.25 μιη. In particular, the thickness of the skin is up to 10 μιη. The stirring speed can be adjusted, in particular for adjusting the shell thickness, whereby a thinner shell is generally obtained the harder agitation (such as stirring) is achieved.

If desired, the particle may comprise one or more cores (of second phase) and / or more than one shell. A subsequent shell can be applied in a conventional manner, or optionally by using the particles (prepared) according to the invention as a second phase in a subsequent method according to the invention using, for example, another polymer A.

It is also possible to prepare particles in which the particles comprise more than one compartment with a second phase which are surrounded by a substantially continuous phase, for example as schematically shown in Figure 2. The second phases in the compartment can be the same. It is also possible to prepare particles with different second phases.

By means of the invention, it has surprisingly proved to be possible to choose conditions such that a substance that is at least substantially insoluble in the solvent is preferentially dispersed in the dispersed phase.

In an embodiment of the invention in which first the edible material for said second phase is mixed with a solution of the first polymer, for reasons of effectiveness, the polymer A is preferably used at least in step a) and the polymer B is preferably used at least in the second solution for forming the continuous phase of the double suspension. To this end, polymer A and polymer B are chosen such that the second phase is more in contact with the solution of polymer A than with solution of polymer B. This can be determined empirically on the basis of general professional knowledge and what is described herein.

Polymer A and polymer B are different from each other. In particular, polymer A and / or B can be selected from edible biopolymers, in particular from the group of edible polypeptides, including edible proteins, and edible polysaccharides, more in particular from the group of whey proteins (such as beta lactoglobulins, alpha-lactalbumin, imunoglobulins), casein, chicken protein, soy protein, gelatin, dextran (in particular non-derivatized dextran), caseinate, alginate, starch, starch hydrolyzate (such as glucose syrups, maltodextrins), a polymer from starop, such as amylopyl or amylose, pectin, cellulose, including derivatives thereof, which are permissible for use in a foodstuff, such as, for example, an alkyl cellulose, in particular methyl cellulose, or an alkoxy pectin, for example methoxy pectin, lupine bean protein, coconut milk protein, arabic gum, locust bean gum, caragen enan , fenugreek gum, guar gum, tara gum and cassia gum 11

Preferably polymers A and B are of a different class. Examples of different classes are in particular the class of polypeptides, including proteins, and the class of polysaccharides. Good results have been obtained with a polypeptide, in particular a protein, such as polymer A and a polysaccharide, in particular a dextran or a cellulose which may be dextranised or cellulose derivatized, as polymer B. Very good results are achieved when the protein if polymer A is partially or completely pre-denatured or otherwise activated for cross-linking.

Denaturation methods are generally known. Examples of this are described in US 5,601,760 and in EP 1 042 960.

Activation can be realized in particular with the aid of heating and / or a high-pressure treatment, for example as described in WO 07/136263. The polymer A to be crosslinked, preferably a protein, more preferably whey protein, is preferably activated so that it has a reactivity as determined by Ellman's assay (Ellman, G.L.

Tissue sulfhydryl groups. Arch. Biochem Biophys. 19959, 82, 70-77), from about 0.1 to about 0.3 mM thiol or sulfhydryl groups per 2% by weight solution of the polymer.

In a particular embodiment of the invention, the first and the second polymer are charged under conditions in which the double suspension is formed and / or after formation of the double suspension.

Very suitable is a method in which the first and the second polymer are charged at and / or after forming the double suspension, wherein the net charge of the first polymer is positive and wherein the net charge of the second polymer is positive or wherein the net charge of the first polymer is negative and wherein the net charge of the second polymer is negative.

Negatively charged polymers can for instance be selected from proteins, other polypeptides and other amphoteric polymers with a 12 isoelectric point that is lower than the pH in the liquid polymer mixture or the double suspension (under the applicable conditions), and polymers with a or more acid groups of which at least a substantial part is deprotonated (under double suspension-forming conditions).

In particular, one or more negatively charged polymers can be selected from the group consisting of alginate, pectin, carbxoymethyl cellulose, gum arabic, and the aforementioned proteins above their isoelectric point.

Positively charged polymers can for example be selected from proteins, other polypeptides and other amphoteric polymers with an isoelectric point higher than the pH in the liquid polymer mixture or the double suspension (under the applicable conditions), and polymers with one or more basic groups of which at least a substantial part is protonated (under double suspension-forming conditions).

In particular, one or more positively charged polymers can be selected from the group consisting of amino polysaccharides and proteins (at a pH below the isoelectric point). More in particular, a protein can be selected from the group of chicken protein, gelatin and potato protein. A particularly suitable amino polysaccharide is chitosan.

In a particular embodiment, two polymers are used that are net uncharged at the pH at which the particles are formed. By net uncharged is meant that the polymer is at least substantially free of charge or that the number of positive charges is at least substantially equal to the number of negative charges (such as with a protein or other amphoteric polymer: at a pH equal to the electrical point).

In a special embodiment, at least one of the following combinations of first and second polymer is used: whey protein, which is wholly or partly denatured or activated (for crosslinking, see above) if desired, and pectin or 13 amylopectin (in the case of a pH above the isoelectric point of whey protein), preferably at a pH of at least 6, particularly preferably at a pH of 6-7; or whey protein, optionally wholly or partially denatured or activated (for cross-linking, see above), and dextran (at a pH around the isoelectric point of whey protein), in particular at a pH of 5.0-5.4, more particularly at a pH of 5.2.

alginate and caseinate, wherein the pH is above the isoelectric point of caseinate at least when forming the double suspension.

The pH herein is the measured pH value as measured in the double suspension with a pH electrode (calibrated in with an aqueous buffer solution at pH 7).

At least if it is desired to fix the polymer for the first phase, at least the polymer for the first phase (polymer A) is preferably crosslinkable. Certain polymers, such as sulfur-containing proteins, can be cross-linked by heating (with sulfur bridges providing cross-linking), such as, for example, whey proteins such as beta-lactoglobulin and alpha-lactalbumin, soy protein and chicken protein. More preferably, the cross-linking takes place partially or completely by heating before adding the second phase.

If desired, an additional fixation can be obtained in addition to heat-induced cross-linking, by adding one or more salts, preferably 2-valued cations, and / or by changing the pH such that the charge of the polymer A decreases (ie a pH-change towards the iso electric point of the polymer A, if this is an amphoteric polymer, such as a protein).

Certain carbohydrates, such as alginates, pectin, and the like, can be cross-linked by the addition of cations such as calcium. A number of polymers can be crosslinked by acidification or under the action of an enzyme. For example, an enzyme such as a transglutaminase is very suitable for cross-linking a protein under mild conditions. Chemical cross-linking reactions (by reaction with a cross-linking agent) are also possible.

The polymer which is at least substantially intended for the continuous phase of the double suspension (polymer B) is, if desired, chosen such that it is fixed at least substantially not under the conditions under which the polymer for the first phase (polymer A) being fixed. Very suitable is, for example, a heat-cross-linkable protein for the first phase and a polysaccharide, such as a dextran as a non-cross-linking polymer.

Suitable concentrations for polymer A and polymer B can be determined empirically depending on the polymers selected.

The concentrations of the polymers A and B are preferably chosen such that the solvents remain separated during the suspension under step b), the concentration in the suspended phase (the suspension formed under step a) being the weight concentration of the polymer A (Ca ) higher and the weight concentration of the polymer B (Cb) lower than the respective concentrations in the continuous phase of the double suspension.

As a rule, a concentration based on weight is suitable which is such that Ca in the first phase is 2-50 times higher than in the continuous phase and / or Cb in the first phase is 2-50 times lower than in the continuous phase. It is thus possible to prepare a suspension in which there is no or hardly any exchange of polymers between the different phases.

The concentrations for polymer A and B can be chosen in broad ranges. In general, a suitable concentration for polymer A and for polymer B can be found in the range of 0.5 wt. % to 20 wt. %, based on the weight of the double suspension, in particular in the range of 1.0 to 10 wt. % based on the weight of the double suspension.

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In particular, the concentration of polymer A in the double suspension can be in the range of 1.0 wt. % to 7 wt. %, more in particular of 2 wt. % to 5% by weight.

In particular, the concentration of polymer B in the double suspension can be in the range of 1.0 wt. % to 7 wt. %, preferably in the range of 2% to 5% by weight.

In particular for obtaining at least substantially completely encapsulated particles, polymers A and B are preferably chosen such that the phase to be encapsulated has more affinity for the suspended phase than for the continuous phase.

In principle, any solvent can be used for the liquid phases (in particular insofar as they are soluble in each other or at least fully miscible with each other, at least below the temperature at which the process is carried out).

The solvent for polymer A and the solvent for polymer B can thus be polar or non-polar. Preferably the solvent for each of the liquid phases is polar, i.e. water or water miscible or soluble. Particularly suitable are liquids selected from the group consisting of water, aqueous solvents and water-miscible solvents, such as water-miscible alcohols, in particular methanol, ethanol, propanol, glycerol; water-miscible ketones such as acetone; and mixtures thereof.

A solvent for polymer A and / or B is preferably selected from the group of water, aqueous solvents and water-miscible solvents, such as a water-miscible alcohol or ketone. The solvent here is preferably water or a liquid which consists at least substantially of water, i.e. for more than 50 to 100 wt. %, in particular for at least 75 wt. %, more in particular for at least 95 wt. %, such as for at least 99 wt. %.

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If different solutions are first made from polymer A and from polymer B, the solvents in said solutions are preferably the same or at least in the absence of polymers A and B mutually soluble or fully miscible at the temperature at which the double suspension is prepared .

Optionally, the pH value can be adjusted to facilitate phase separation. In particular, if a polypeptide or other amphoteric polymer is used to adjust the pH to a value around the isoelectric point of the amphoteric polymer.

The second phase comprises a material that is solid at least at room temperature, a liquid, a gas and / or a microorganism that at least substantially does not dissolve on a molecular scale in the polymer solutions. In particular, by at least substantially non-dissolution is meant that more than 50 wt. %, preferably more than 90 wt. %, in particular more than 99% of the solid material, the liquid, the gas or microorganism for the second phase does not dissolve under the preparation conditions

The second phase can take the form of solid particles, liquid particles (drops), bubbles or particles of one or more microorganisms in the suspension. Combinations of these are also possible, for example microorganisms in a liquid or a mixture of microorganisms and a carrier, for example a dietary fiber.

The size of the particles or bubbles can be chosen within wide limits. In particular, the invention relates to at least substantially spherical particles.

Usually, the number average particle size (diameter) of the particles or bubbles as detectable by microscopy, preferably in two or three dimensions, is at least 1 µm, preferably at least 5 µm. The number average particle size is preferably a maximum of 100 μιη, in particular a maximum of 50 μιη.

In particular, the solid material, the liquid, the gas and / or the microorganism for said second phase can be selected from the group of proteins, more specifically enzymes; peptides; flavorings; herbs; spices; oils; fats; prohiotics (i.e., bacteria desired in the gut flora); prebiotics; air, nitrogen, carbon dioxide, nitrous oxide (nitrous oxide), oxygen, and mixtures thereof; salts; minerals; crystals, in particular from a carbohydrate such as sugar or from a (mineral) salt; At least substantially water-insoluble substances, such as beta-carotene and sterols, at least substantially water-insoluble enzymes such as coenzyme Q10, and at least substantially water-insoluble vitamins, such as vitamin A and other fat-soluble vitamins.

The oils and fats can in particular be selected from vegetable and animal oils and fats, including saturated, monounsaturated and polyunsaturated oils and fats, including mixtures of fats and / or oils, such as fish oil.

Examples of good bacteria are in particular Lactobacilli and Bifidobacteria.

Particularly suitable prebiotics are prebiotic carbohydrates, such as fructooligosaccharides, galactooligosaccharides, inulin, and the like.

The invention further relates to a double suspension, such as a double suspension obtainable by a method comprising steps a) and b) as defined in a method according to the invention, which suspension comprises edible particles, which particles have at least a first phase (which at least is solid at room temperature) comprising a first polymer, which first phase at least substantially surrounds a second phase, which second phase (at least at room temperature) is solid, liquid or gaseous and / or a microorganism, the particles are suspended in a third phase which comprises a solution of a second polymer. The concentration of the first polymer in the first phase is preferably 2-50 times higher than in the third phase and / or the concentration of the second polymer in the first phase is preferably at least 2 times lower than in the third phase .

In one embodiment the invention relates to a method for preparing an encapsulated gas bubbles. Such a method is very suitable for stabilizing gas bubbles. In such a method a), the first solution comprising the first edible polymer (usually polymer A) is foamed with the gas; and b) the foam is then stirred by the second solution comprising the second edible polymer (usually polymer B).

The foaming can be carried out using a conventional whipping method such as a rotor-stator mixer. Incidentally, any method of foaming can be applied.

By crosslinking or otherwise fixing the first polymer, a stabilized foam is created.

The term "stabilized" in this context refers to the possibility of storing the encapsulated gas bubbles for a longer period of time without previous changes in the size of the gas bubbles present leading to undesired coarsening and / or other undesirable structural changes.

It has been found that it is possible by means of the invention to obtain a foam in which the bubbles do not substantially increase within a desired period, in particular a period of at least one week, in particular when as polymer A a protein, in particular a milk protein is selected and optionally as polymer B a polysaccharide.

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In particular, it is possible to stabilize a foam against disproportionation of the gas bubbles for at least a certain time by creating a rigid surface (the fixed polymer) on the bubbles. In other words, the stability is not primarily caused by the bulk of the product.

The fixing can be done in a manner as described herein, in particular by cross-linking.

In a preferred embodiment, use is made of a protein to form the first phase, in particular of a whey protein. In particular, it has been found that for a material to be encapsulated, such as oil droplets, air bubbles or bacteria, the use of (whey) protein as a polymer in the envelope phase (second phase) gives good results. Whey protein is also advantageous for providing particles with a low digestion rate. Particularly of particles comprising a cross-linked whey protein, a low digestion rate has been found.

The protein molecules present, or at least a part thereof, can be interlinked with the aid of a heating step in which the foodstuff is heated above the denaturation temperature of the proteins for a sufficiently long time. The foamed product is thus subjected to a heating such that at least a part of the proteins unfolds and cross-links with each other. For milk protein, such a heating comprises, for example, 4 minutes 45 seconds at 90 ° C, but other temperature / time combinations are also possible, for example half an hour at 80 degrees C.

Incidentally, prior to approval methods and devices applicable in the method for preparing encapsulated gas bubbles (for step a and / or the desired crosslinking) are described in detail in the patents with numbers NL1 024 433, NL 1 024 43, NL 1 024 435 and NL 1 024 438. The methods and devices described therein are incorporated herein by reference as preferred embodiments of the present method. Another suitable cross-linking method involves the use of an enzyme, such as, for example, transglutaminase.

The average hell size of the encapsulated gas bubbles according to the invention can be determined with microscopic techniques. As a rule, the bubbles will have a largest diameter in the range between 1 and 500 µm. In a preferred embodiment it is at least 5 and / or at most 100 µm.

It has been found by means of the invention that compared to a known method of stabilizing a foam, such as for instance a method described in NL 1 024 435, it is possible to achieve a higher stability with the same hell size, and / or a comparable stability with a larger hell size. It is suspected that the possibility of making encapsulated bubbles with a relatively thick surrounding phase contributes to this.

The layer thickness of the surrounding phase is usually at least 0.1 µm, in particular at least 0.15 µm, preferably at least 1 µm.

The layer thickness of the surrounding phase is usually a maximum of 10 µm, preferably a maximum of 5 µm.

By means of the invention it is possible to make a foam with a large degree of dimension stability, with a certain thickness of the layer. It is thus possible to obtain a foam in which the average diameter of the bubbles is at least substantially retained for a period of 7 days or more.

The product according to the invention can be used as an ingredient or component of foodstuffs such as dairy products and fruit and fruit juices. This application gives the food product enriched with the product according to the invention a number of advantageous properties. This way it can serve as a fat substitute; it makes the food taste creamier and / or leads to a softer mouthfeel.

The foam is suitable, for example, for addition to a mousse, whipped cream, ice cream, cappuccino foam, a topping, a cream base 5 or meringue.

The invention also relates to edible particles obtainable by a method according to the invention. In particular, such particles comprise at least mainly polymer A in the first phase. Polymer A is more preferably a protein, in particular a cross-linked or learned protein. Preferably, the concentration of polymer A as a percentage by weight of the sum of polymers A and B is at least 50%, in particular at least 90%. If present, the concentration of polymer B in the first phase of the particles is usually 5 to 50 wt. %, in particular a maximum of 10 wt. %.

In one embodiment, a particle according to the invention is characterized by a high degree of smoothness, for example in comparison with particles prepared by complex coacervation, in which, for example, a protein and a polysaccharide are present in a ratio of about 1: 1 in the surrounding phase of the 20 particle. Without being bound by theory, it is suspected that this could be related to a possibly high degree of homogeneity of the first phase in particles according to the invention.

It has further been found that by means of the invention it is possible to protect the second phase against environmental influences, in particular in an embodiment according to the invention in which the first phase, such as a protein, is cross-linked. Without being bound by theory, it is suspected that it is possible by means of the invention to provide a protective layer or an improved barrier layer around the second phase in one or more respects than in a conventional method such as, for example, complex coacervation, by first taking the first phase around the second 22 phase and only then to fix the first phase, in particular to tie it afterwards.

The protective effect can be, for example, a reduced degradation rate of the second phase, for example a reduced digestion rate of a food or ingredient therefor, under gastrointestinal conditions, compared to encapsulated particles obtained in a conventional manner or an unprotected second phase.

It has also been found that in particles according to the invention the second phase may be protected against oxidation by the presence of the first phase.

Furthermore, in one embodiment the first phase can offer some degree of protection against damage to the second phase under the influence of shear forces, in particular if the second phase is a fairly soft material, such as a fat globule or if the second phase is liquid, for example an oil. More specifically, the first phase can offer some degree of protection against damage to an emulsion, such as oil droplets filled with water droplets, surrounded by the first phase.

If a phase other than a gaseous phase is used as the second phase, it is advantageous to properly encapsulate the second phase to degas the suspension prior to spray drying and / or to carry out the spraying without introducing air into the nozzle. to take place. This is particularly advantageous if an oxidation-sensitive substance, for example fish oil, is encapsulated by the invention. Hereby, for example, a spray can be chosen in a relatively low nozzle pressure range: for example in the range of 20-60 bar or an additional flow of moist air or (saturated) steam can be introduced.

Particles thus obtained usually have a relatively high density. In absolute terms, it will depend to a certain extent on, in particular, the second phase used. The density of such 23 particles can in particular be in the range of 1.0 to 1.4 g / ml, preferably of 1.2 to 1.3 g / ml. A density in the range of 1.0-1.4 g / ml can be obtained in particular with particles consisting at least substantially of protein, oil and / or fat, and carbohydrate, more in particular for particles that are 30- 50 wt. % oil and / or fat, 30-50 wt. % carbohydrate and 10-40 wt. % protein, provided that the sum of these levels is at most 100%, preferably 90-100%.

A final fixation of polymer A will occur in the case of use of pre-denatured or otherwise activated protein during the drying process from droplet to powder particle. The use of one or more additives such as one or more antioxidants (e.g. ascorbate or salts or derivatives thereof), carrier material such as one or more polyols or carbohydrates (e.g. hydrolyzed starch such as maltodextrin or glucose syrup) in addition to the polymer B present in the continuous phase

The invention furthermore relates to a foodstuff comprising a double suspension or edible particles (prepared) according to the invention, preferably a dairy product, particularly preferably a foodstuff selected from the group of cheese, yogurt, whipped cream, mousses, desserts, dairy drinks, ice cream, cappuccino foam, toppings, cream bases and meringues.

The invention further relates to a pharmaceutical composition comprising a double suspension or particles (prepared) according to the invention, which particles contain a pharmaceutically active substance. The pharmaceutical composition is preferably a vaccine.

The invention is now illustrated with reference to a number of examples.

24

Example 1: Encapsulation of oil droplets in whey protein, using cross-linking by spray drying

A 5 wt% whey protein (Hiprotal 580, DOMO) aqueous solution 5 (100 L) was kept at a temperature of 80 ° C for 30 minutes, after which an amount of high methoxy pectin (1.7) was cooled after 50 ° C kg; YM-100H from CP Kelco) was added, followed by corn syrup (15.1 kg; Glucidex IT 33, from Roquette).

After good stirring for 10 minutes at 45 ° C, oil (10 kg; 10 Marinol D-40, from Lipid Nutrition) was mixed in, also followed by good stirring, such that an average oil droplet distribution of 10-20 microns was obtained. This solution was then homogenized such that oil droplets of 1-2 microns were obtained. Homogenization pressures of 50-100 bar used for this gave the desired result.

Then after pasteurization at a temperature of 75 ° C

for 20 seconds, the resulting solution was spray-dried in a Filtermat installation by means of a high-pressure spray at pressures in the range of 30-60 bar with suitable nozzle systems as available in the market (e.g. Schlick GmbH). The drying conditions were typically in the range of an inlet temperature of 170 ° C and an outlet temperature of 70 ° C.

The powder obtained was then tested for oxidation stability by means of an accelerated shelf life test at 40 ° C under air, taking various aspects of the sensor system into account.

A comparison was made with a standard type of fish oil capuchate available in the market that had the same type and loading oil of 30% (Vana Sana DHA 7 IF, Friesland Foods Kievit).

In conclusion, the effect of the example according to the invention is a more neutral scented powder as well as an even or even more sensory neutral and stable powder relative to a reference powder when used in the application

Example A Example A Reference Reference Time Odor powder Flavor Odor Flavor application * powder application * Week 0 neutral neutral Slightly fishy neutral

Week 4 neutral neutral Something fishy neutral

Week 8 neutral neutral Slightly fishy, Slightly fishy paint-like * Application: solution of 1 gram of powder in 100 grams of milk at 40 ° C.

5

Example 2: Encapsulation of probiotics (BB12) in whey protein, using crosslinking by acidification

A 5 wt% whey protein (preferably Hiprotal 580, DOMO) solution in water (1001) was kept at a temperature of 80 ° C for 30 minutes, after which an amount of high methoxy pectin (1, after cooling to 50 ° C) 7 kg; YM-100H from CP Kelco) was added, followed by corn syrup (15.1 kg Glucidex IT 33 from Roquette). After good stirring for 10 minutes at 45 ° C, probiotics (10 kg of Bifidobacteria, BB12, by Chr. Hansen) were mixed in, also followed by stirring.

Subsequently, 0.15 kg of glucono-delta lactone (Lysactone from Roquette) was added to the resulting solution and the mixture was stirred gently at 40 ° C for a period of 30 minutes, so that a pH reduction from pH 6.7 to pH

5.0 was achieved, with cross-linking of the protein taking place and particles 20 in which the probiotics were encapsulated. A photograph of prepared particles is shown in Figure 3.

Claims (17)

1. A method for preparing edible particles comprising at least a first phase, which first phase surrounds at least substantially a second phase, which second phase is solid, liquid or gaseous and / or comprises a microorganism, the method comprising suspending an edible solid material, liquid, gas and / or microorganism (for said second phase) in a liquid comprising a first edible polymer and a second edible polymer and forming a double suspension, wherein at least one polymer (polymer A said first and second polymer is at least substantially present in the suspended phase of the double suspension and at least one other polymer (polymer B) of said first and second polymer is at least substantially present in the continuous phase; and c) crosslinking or otherwise fixing polymer A. 2. Method according to claim 1, wherein first a liquid mixture is prepared from the first and the second polymer and then the second phase is added to the liquid mixture, or to the double suspension formed from the liquid mixture. Method according to claim 1 or 2, comprising d) isolating the formed particles. A method according to any one of the preceding claims, wherein the first and the second polymer are charged in forming the double suspension, wherein the net charge of the first and the second polymer is both positive or both negative under the conditions where the double suspension is formed. The method of claim 4, wherein the first and the second polymer are pectin and whey protein, wherein pH is at least when forming the double suspension above the isoelectric point of whey protein, or wherein the first and the second polymeric alginate and caseinate, the pH being at least when forming the double suspension above the isoelectric point of caseinate. 6. A method according to any one of claims 1-4, wherein the first and the second polymer are net uncharged at least when forming the double suspension. 7. A method according to any one of the preceding claims, wherein the polymer A and / or B is selected from the group of biopolymers, in particular from the group of proteins and polysaccharides, more in particular from the group of whey proteins ( such as beta-lactoglobulins, alpha-lactalbumin, imunoglobulins), casein, soy protein, potato protein, gelatin, chicken protein, guar gum, carrageenan, dextran, caseinate, alginate, starch, pectin, cellulose, including derivatives thereof. 8. A method according to any one of the preceding claims, wherein the edible solid material, liquid, gas and / or microorganism (for said second phase) is selected from the group of proteins; enzymes; peptides; flavorings; fragrances; herbs; spices; oils; fats; probiotics; "good" bacteria; prebiotics; carbon dioxide, nitrogen, nitrous oxide, oxygen and mixtures thereof, such as air; salts; minerals; crystals, in particular of a carbohydrate such as sugar; sparingly water-soluble substances such as beta-carotene or sparingly soluble enzymes such as coenzyme Q10 and vitamins such as vitamin A and other vitamins, in particular other fat-soluble vitamins. 9. A method according to any one of the preceding claims, wherein the first phase comprises a gas, wherein a) the first solution comprising the first edible polymer (A) is foamed with the gas; and b) the foam is then stirred by the second solution comprising the second edible polymer (B). The method of any one of the preceding claims, wherein polymer A is crosslinked by spray drying. A method according to any one of the preceding claims, wherein the concentration of polymer A in the double suspension is in the range of 0.5% to 10% by weight. % preferably of 1 wt. % to 7 wt. %. and / or the concentration of polymer B in the double suspension is in the range of 0.5 wt. % to 10 wt. %, preferably from 1% by weight to 7% by weight. %. 12. Double suspension, such as a double suspension obtainable by a method comprising steps a) and b) as defined in one of the preceding claims, which suspension comprises edible particles, which particles at least a first phase (which is solid at least at room temperature) containing a first polymer (A), which first phase comprises at least substantially a second phase, which second phase (at least at room temperature) is solid, liquid or gaseous and / or comprises a micro-organism, the particles being suspended in a third phase comprising a solution of a second polymer (B). The double suspension according to claim 12, wherein Ca in the first phase is 2-50 times higher than in the third phase and / or Cb in the first phase is at least 2 times lower than in the third phase. Edible particles obtainable by a method according to any of claims 1-11. 15. Edible particles, according to claim 14, which particles contain at least a first phase, which is solid at least at room temperature, which comprises a first cross-linked polymer A, which first phase at least substantially surrounds a second phase, which second phase is gaseous and wherein the average thickness of the first phase is 0.1-10 µm. Edible particles according to claim 14 or 15, wherein polymer A comprises a cross-linked protein, preferably cross-linked whey protein. 17. A foodstuff comprising a double suspension according to claim 12 or 13 or edible particles according to any of claims 14-16, preferably a dairy product, particularly preferably selected from the group formed by cheese, yogurt, whipped cream, mousses, desserts, dairy drinks , ice cream, cappuccino foam, toppings, cream bases and meringues.