WO2011117738A2

WO2011117738A2 - Solid flavor encapsulation by applying complex coacervation and gelation technology

Info

Publication number: WO2011117738A2
Application number: PCT/IB2011/001060
Authority: WO
Original assignee: Philip Morris Products S.A.
Priority date: 2010-03-26
Filing date: 2011-03-28
Publication date: 2011-09-29
Also published as: RU2592876C2; KR20130008564A; WO2011117738A8; WO2011117738A3; CN102821621A; RU2012145459A; EP2552239A2; JP2013523091A

Abstract

A coated solid flavor particle comprises: a base particle comprising a solid flavor particle; a first polymeric coating material at least partially coating the base particle, said first coating material being selected from the group consisting of proteins, cationic polysaccharides or oligosaccharides, non-ionic polysaccharides or oligosaccharides, and mixtures of them; and a second polymeric coating material at least partially coating the first coating, said second coating material being selected from polysaccharides, proteins, a mixture of polysaccharides, a mixture of proteins, or a mixture of polysaccharides and proteins.

Description

SOLID FLAVOR ENCAPSULATION BY APPLYING COMPLEX COACERVATION

AND GELATION TECHNOLOGY

BACKGROUND

It is desirable to provide for greater stability of solid flavors added to smokeable or orally- enjoyable products. It is also desirable to provide for sustained oral release of flavors.

SUMMARY

According to the invention there is provided a coated solid flavor particle comprising a base particle comprising a solid flavor particle; a first polymeric coating material at least partially coating the base particle, said first coating material being selected from the group consisting of proteins, cationic polysaccharides or oligosaccharides, non-ionic polysaccharides or oligosaccharides, and mixtures of them; and a second polymeric coating material at least partially coating the first coating, said second coating material being selected from polysaccharides, proteins, a mixture of polysaccharides, a mixture of proteins, or a mixture of polysaccharides and proteins.

The invention further provides a palatable or comestible product comprising one or more such coated particles.

According to the invention there is also provided a method for preparing coated solid flavor particles, comprising combining solid flavor particles and a first polymeric coating material in a liquid medium, wherein the first polymeric coating material adsorbs onto at least a portion of a surface of the particles to form a first layer, mixing a second polymeric coating material with the liquid medium, wherein the second polymeric coating material adsorbs onto at least a portion of a surface of the first layer to form a second layer, and spray-drying the particles to form coated solid flavor particles.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 is a cross-sectional depiction of a preferred embodiment of a solid flavor particle with two coatings.

Figure 2 is a flow chart of a preferred embodiment of a method for manufacturing the encapsulated solid flavor particles.

Figure 3 is a thermogravimetric analysis ("TGA") of an exemplary solid flavor encapsulation as described herein.

Figure 4 is a TGA plot of encapsulated solid flavors as compared to pure solid flavor precipitate and individual encapsulants.

Figure 5 shows the rate of change (derivative) of the curves plotted in Fig. 4.

Figure 6 is a TGA plot of encapsulated solid flavors containing soy and rice proteins. Figure 7 shows the rate of change (derivative) of the curves plotted in Fig. 6.

DETAILED DESCRIPTION

As described herein, solid flavorants are encapsulated using complex coacervation technology.

As used herein, the term "smoking article" includes any material, article or device that is typically used to enjoy tobacco or tobacco substitutes by inhalation or smoking, including but not limited to cigars, cigarettes, pipe tobacco, loose or "roll-your-own" tobacco, electronically heated cigarettes, and the like.

As used herein, the term "smokeless tobacco" includes tobacco intended to be enjoyed in some manner other than inhalation or smoking, e.g., taken orally. Examples include snuff, pouched tobacco including snus, dip, plug tobacco, and the like.

A "tobacco product" as used herein includes both smoking articles and smokeless tobacco.

As used herein, the term "orally enjoyable" denotes the ability of a material or product to be enjoyed and at least partially consumed via the mouth. An orally-enjoyable product may be a tobacco product (for example smokeless tobacco) or non-tobacco product (for example a palatable or comestible product in the form of a tablet, stick, chewable gum, spongy material, foam, cream, or fibrous or pelleted material, a form suitable to be contained in a pouch, or combinations thereof).

As used herein, the terms "flavorant" and "flavorant composition" denote organoleptic compounds and compositions that are applied to a substrate or article, at least in part in order to alter the taste or aroma characteristics of the substrate or article during consumption thereof.

A "liquid flavorant composition" as used herein is a flavorant composition that is in a liquid form, or that can be rendered into liquid form by dissolution, suspension, or similar processes, under conditions typically encountered for the storage of the flavorant composition or of the article to which the flavorant composition is to be applied.

As used herein, the term "about" when used in conjunction with a stated numerical value or range has the meaning reasonably ascribed to it by a person skilled in the art, i.e. denoting somewhat more or somewhat less than the stated value or range, to within a range of ±10% of the stated value.

Encapsulation of solid flavors as described herein provides numerous advantages over other forms of flavor delivery. The disclosed methods relate how to encapsulate flavors from both solids and liquids, soluble in water or solvents, by using a pre-precipitation and particle surface modification step. Thus a controlled time of release and multiple release profile of flavor are achieved, along with ease of use of the encapsulated form in different matrices and smokeable or smokeless forms, and desirably altered aesthetics by converting a very deep colored flavor to a light tan or a very lighter shade. Flavorants

Flavors to be encapsulated as described herein may originate as solids or liquids and may be soluble in water or in an organic solvent. Preferably, solid flavor particles are obtained by precipitation of a liquid flavor or drying of a liquid flavor. If already provided in solid form, the solid flavor may be prepared appropriately before encapsulation.

Suitable flavorants include, but are not limited to, berry flavors such as pomegranate, acai, raspberry, blueberry, strawberry, boysenberry, and/or cranberry. Other suitable flavorants include, without limitation, any natural or synthetic flavor or aroma, such as menthol, peppermint, spearmint, wintergreen, bourbon, scotch, whiskey, cognac, hydrangea, lavender, chocolate, licorice, citrus and other fruit flavors, such as apple, peach, pear, cherry, plum, orange, lime, grape, and grapefruit, gamma octalactone, vanillin, ethyl vanillin, breath freshener flavors, butter, rum, coconut, almond, pecan, walnut, hazelnut, french vanilla, macadamia, sugar cane, maple, cassis, caramel, banana, malt, espresso, kahlua, white chocolate, spice flavors such as cinnamon, clove, cilantro, basil, oregano, garlic, mustard, nutmeg, rosemary, thyme, tarragon, dill, sage, anise, and fennel, methyl salicylate, linalool, jasmine, coffee, olive oil, sesame oil, sunflower oil, bergamot oil, geranium oil, lemon oil, ginger oil, balsamic vinegar, rice wine vinegar, and red wine vinegar.

If the flavorant is in liquid form, it is preferably treated to obtain solid flavor, for example by precipitation. Preferably hydrophobic flavors may be precipitated by water. Hydrophilic solid flavors may be precipitated by using an organic non-solvent. A solid flavor may also be obtained by drying a liquid flavor, preferably by freeze drying. Care should be taken to avoid loss of volatile flavor components, particularly when obtaining a solid flavor by drying (and thus freeze drying is preferred).

The solid flavorant can optionally be treated to form particles of a small size, such as by grinding with a ball mill or by using a homogenizer. Suitable homogenizers include those used to form small form small particles, such as homogenizers manufactured by Microfluidics Corporation. Preferably, the flavorant is ground until the particles are micronized, i.e., having an effective cross section measured in microns. Preferably, the flavorant particles will have a cross section less than about 1000 microns, and typically between about 0.2 and about 250 microns, more particularly between about 1 and about 100 microns. The particles can have any desired shape, such as different regular and irregular shapes. Suitable regular shapes include round, square, rectangular, oval, other polygonal shapes, cylindrical, fibrous, and the like.

In a preferred embodiment, the solid flavorant is hydrophobic. If the solid flavorant is not hydrophobic, a hydrophobic coating can optionally be applied to the solid flavorant prior to encapsulation. Formation of the hydrophobic coating around hydrophilic flavor powders or precipitates may be possible by using hydrophobic proteins, hydrophobic polysaccharides, modified starches and celluloses, emulsifiers, fatty alcohols, fatty esters, and/or waxes. A hydrophobic provides benefits in that it protects the flavor during subsequent coating steps, and also increases sustained release when the resulting coated solid flavor particle is in the mouth, as the hydrophobic coating will repel saliva.

First Polymeric Coating

Once a solid flavor particle is obtained, and optionally coated with a hydrophobic coating, it may be coated with a first polymeric coating.

The first polymeric coating material may be selected from the group consisting of proteins

(including protein hydrosylates), cationic polysaccharides or oligosaccharides, non-ionic polysaccharides or oligosaccharides, and mixtures of them. If the solid flavor particle is charged, it is desirable to select a first coating material that has a charge that will be attracted to the charge possessed by the solid flavor particle.

In one aspect there is provided a coated solid flavor particle which comprises a base solid flavor particle which can be charged or neutral, an optional hydrophobic coating, a first polymeric coating material coating at least a portion of, and preferably all of, the base particle and a second polymeric coating material disposed at least partially on said first coating material. The first coating material can be neutral, Zwitterionic or ionic, preferably cationic. The first coating material is preferably selected from the group consisting of proteins (including protein hydrolyzates), cationic polysaccharides, cationic oligosaccharides, non-ionic polysaccharides, non-ionic oligosaccharides, and mixtures of them. The second coating material can also be ionic, Zwitterionic or neutral.

The first polymeric coating material may comprise (i) a protein or protein hydrolyzate, especially a Zwitterionic or cationic protein in the case where the solid flavor particle is negatively charged, (ii) a cationic polysaccharide, or preferably a cationic polysaccharide selected from the group consisting of chitosan, quaternary cellulosic polymers, modified cationic polysaccharides, polyquat-4, amidated pectins, and amidated or cationically modified starches, especially when the solid flavor particle is negatively charged, or (iii) non-ionic polysaccharide, a polyvinyl pyrrolidone, a poly vinyl alcohol, or combinations thereof. If the first coating material is a non-ionic polysaccharide, it may be selected from the group consisting of modified starches, or methyl cellulose and derivatives thereof, including hydroxyl propyl methyl cellulose, propylene glycol ester of alginic acid, agar, curdlan, and modified pectins, such as those of citrus, apple, plum, gooseberry, or tobacco plant origin. Combinations of two or more of these materials may be used.

If the first polymeric coating material is a protein, it may be a plant-based or animal-based protein, and preferably is, or is derived from, a milk protein, a fish gelatin, a whey protein, an egg white protein, a rice protein, a soy protein, a wheat protein, a tobacco protein or a protein fraction from a tobacco plant, a protein from or derived from tobacco extract, or combinations thereof, a gelatin other than fish gelatin, corn protein, or protein hydrolyzates, or the protein may contain a high content of amino acid groups with a nitrogen-containing (preferably non-cyclic) side chain, such as lysine, asparagine, glutamine and arginine, which are beneficial for cross linking with carbohydrate carboxylic groups under processing conditions. Gelatins other than fish gelatin include beef gelatin, pork gelatin and gelatin hydrolyzates. Fish gelatin, for example, can be produced by comminution of the minced flesh of any of several species of lean fish, e.g., haddock, cod, cusk, cat, and ocean perch. During comminution a small amount of sodium chloride may be added to improve the texture of the finished fish gelatin product.

If an allergen-free product is desired, it is preferred to employ protein derived from fish gelatin, rice protein, oat protein, or corn protein, or their hydrolyzates. It is preferable that the proteins be relatively pure and not treated or "instantized" with surfactants. It may also be preferable to treat the protein or protein hydrolyzate coating with an acid to impart a positive charge to facilitate electrostatic complexation between the protein and a subsequent coating comprising a polysaccharide/oligosaccharide

The first polymeric coating may have a molecular weight between about 2 KDaltons and about 1000 KDaltons, or preferably between about 15 KDaltons and about 500 KDaltons. Second Polymeric Coating

The second polymeric coating material is adsorbed over at least a portion of, and preferably all of, the first coating; the second coating material may be ionic, Zwitterionic or neutral. More particularly, the second polymeric coating material preferably comprises an anionic, Zwitterionic or neutral polysaccharide, a protein (including hydrolyzates), a mixture of polysaccharides, or a mixture of one or more polysaccharides and one or more proteins. The second polymeric coating material may have a molecular weight between about 5 KDaltons and about 1 ,000 KDaltons, preferably between about 100 KDaltons and about 500 KDaltons, more preferably between about 200 KDaltons and about 500 KDaltons.

If the second coating material is an anionic or Zwitterionic polysaccharide, it is preferably selected from at least one of carrageenan, gum arabic, carboxymethyl cellulose, pectins, such as those from citrus, apple, plum, gooseberry or tobacco plant origin, sodium alginate, gum tragacanth, locust bean gum, gellan gum, and xanthan gum.

If the second coating is a nonionic polysaccharide, it is preferably selected from the group consisting of modified starches, methyl cellulose and derivatives of it, hydroxy propyl methyl cellulose, propylene glycol ester of alginic acid, agar, curdlan, and modified pectins of citrus, apple, plum, gooseberry or tobacco plant origin (where the pectins have been modified to be non-ionic). If the second coating is a protein, it may be either plant or animal based, and is preferably derived from milk protein, whey protein, egg white protein, soy protein, rice protein, wheat protein, tobacco protein fractions from tobacco plants or tobacco extracts, fish gelatin, gelatin other than fish gelatin, corn protein, or protein hydrolyzates. If it is desired to provide allergen- free products, the protein may be derived from rice, fish gelatin, oat protein, corn protein or their hydrolyzates. The protein preferably has a net negative or neutral charge under solution pH.

The polysaccharide used as a coating preferably should be substantially free of salts, sugars, or hemicelluloses (e.g., compounds with a molecular weight of between about 1 KDaltons to about 5 KDaltons), and should be preferably non-standardized.

Preferably, at least one of the polysaccharides or proteins in the second polymeric coating can form a gel in the pH range of about 3 to about 9. Alternatively, or in addition, it is preferred that the second coating material further comprises one or more monovalent, divalent, or trivalent cations such as potassium, calcium, magnesium, and iron, in the form of salts such as chloride, citrate, lactate or acetate salts, which may assist in forming salt bridges between the coating materials, particularly when the second coating material includes an anionic or neutral polysaccharide, a protein, a mixture of polysaccharides, or a mixture of polysaccharide and protein. Alternatively, or in addition, the proteins and polysaccharides of the second polymeric coating can gel as a result of crosslinking, hydrogen bonding, hydrophobic interactions, or electrostatic complexation, particularly among carboxylic groups of polysaccharides and amino groups of proteins, or vice versa.

If desired, the protein or protein hydrolyzate in the second polymeric layer can be converted to a positive charge to facilitate electrostatic complexation between the protein and the polysaccharide/oligosaccharide. The conversion of the protein to a relatively positive state may be affected by lowering the pH of the liquid medium with weak food grade organic acids such as acetic, adipic, fumaric, malic, lactic, tartaric and gluconic acids, and gluco delta lactone, or food grade inorganic acids such as strong hydrochloric acid.

Additional Polymeric Coatings

Additional coatings may be added to a twice-coated particle by adding a cationic protein or a cationic or non-ionic polysaccharide to the liquid medium to form a third mixture containing solid flavor particles coated with more than two polymeric coatings. Any subsequent polymeric coating may be any of the materials used in the first or second coating material, or mixtures of them, and the methods described herein for forming the first and second coatings can be used to prepare particles having additional coatings. For example, a third polymeric coating may be added by introducing a third polymeric coating material into the liquid medium prior to drying, so that the third polymeric coating material adsorbs onto at least a portion of the surface of the second coating. After the desired coatings have been applied, the coated particles can preferably be dried to moisture content of less than about 15% by weight water, or if desired, to a moisture content between about 2 and about 5% by weight water.

Gelation

In the preparation of the coated solid flavor particle, inducing gel formation in the first and/or second polymeric coating may be accomplished by adjusting pH, and/or by: (i) adding monovalent, divalent, or trivalent cations to the liquid medium during or after addition of the second polymeric coating material; (ii) heating the third mixture to a temperature of between about 60 °C and about 90 °C for about 1-3 hours; (iii) refrigerating the third mixture at a temperature of between about 20 °C and about 0 °C for about 1 to about 48 hours;

(iv) removing at least part of the liquid medium from the third mixture by spray drying;

(v) removing at least part of the liquid medium from the third mixture by freeze drying; or

(vi) combinations of two or more of (i) to (v).

Formation of a gel network with controlled thickness as described herein, beyond coacervation, can strengthen the encapsulated shell around the solid flavor, which will help in controlled and long lasting release of the flavor. Gel thickness and porosity can be controlled by manipulating concentration of polymeric coating material and crosslinking of the gel layer via ionic, covalent, or enzymatic means or simply by hydrogen bonding.

It is preferred that at least one of the polysaccharides or proteins may form a gel in the pH range of about 3 to about 9, and/or that monovalent, divalent, or trivalent cations may be added to the liquid medium during or after addition of the second polymeric coating material to induce formation of the gel, particularly involving the second or final coating. Cations selected from the group consisting of potassium, calcium, magnesium and iron as chloride, citrate, lactate and acetate salts may be added to the liquid medium during or after addition of the second polymeric coating material to induce formation of the gel, e.g., via formation of salt bridges. As indicated herein, gelation may also be induced or aided by heating (e.g., to a temperature between about 60 °C and about 90 °C for about 10 to about 180 minutes) or cooling (e.g., to a temperature between about 20 °C and about 0 °C for about 1 to about 48 hours) of the gel.

Following contact of the coated solid flavor particle with the final coating material, the liquid content of the mixture containing the coated solid flavor particle can be adjusted as necessary for the drying method employed. If the liquid is to be removed, it may be separated by customary means, such as decanting or filtering. Alternatively, if the solid flavor particle is present in the form of a coacervate gel, water (preferably deionized) or other liquid can be added to the gel to achieve the desired consistency for spray drying or freeze drying. For example, the water content of the gel may be adjusted to contain about 2% w/w concentration of solids in suspension. Drying the Coated Particles

If spray drying is utilized the suspension of coated particles can be, for example, atomized from a liquid feed into a spray of droplets, wherein the droplets can be placed in contact with drying air to form dry coated solid flavor particle. As an alternative to spray drying, the coated solid flavor particle can be passed through a tunnel drier at about 90 °C to about 95 °C to flash off a majority of the liquid, then can be air dried at room temperature to form a final powder. As another alternative to spray drying, the coated solid flavor particles may be freeze dried.

When spray drying, it may be possible to collect encapsulated particles from either the spray dryer collection chamber, or in the spray dryer spray chamber. Temperature and retention times in spray drier may be optimized to provide the optimum binding mechanisms of the solid flavors to proteins and polysaccharides providing different flavor release profiles.

In another embodiment, there is provided a coated solid flavor which comprises a base solid flavor particle, said base particle being electrically charged or neutral, a first polymeric coating material coating the base particle, said first coating material being (i) ionic, cationic, Zwitterionic or neutral, or (ii) selected from the group consisting of proteins (including protein hydrolyzates), cationic polysaccharides or oligosaccharides, non-ionic polysaccharides or oligosaccharides, and mixtures of them, or (iii) combinations of (i) and (ii), and a second polymeric coating material over the first coating, said second coating material being ionic or neutral in charge.

In another embodiment, there is provided a method for manufacturing a bi-encapsulated base particle wherein the base particle comprises a solid flavor particle. More particularly, there is provided a method for preparing coated solid flavor particles, which comprises adding solid flavor particles, either as a powder or as a dispersion of charged or neutral solid flavor particles dispersed in a liquid medium, preferably, an aqueous medium, to a liquid medium containing a dispersion of a first polymeric coating material, wherein the first polymeric coating adsorbs onto at least a portion of a surface of the particles to form a first layer on the particles, then adding a second polymeric coating material to the liquid medium, wherein the second polymeric coating adsorbs onto at least a portion of a surface of the first layer to form a second layer on the once- coated particles, and then removing at least a portion of the liquid medium to form coated particles.

In another embodiment, there is provided a method of preparing coated solid flavor particles which comprises adding solid flavor particles to a liquid medium containing a first polymeric coating material comprising at least one of a protein (including a hydrolyzate), an Zwitterionic biopolymer, and a polysaccharide to form a first mixture containing solid flavor particle at least partially coated with a first polymeric coating; then adding to the first mixture a cationic protein or a cationic or anionic polysaccharide to form a second mixture containing solid flavor particles at least partially coated with a first and a second polymeric coating, and optionally adding to the second mixture a cationic protein or a cationic or non-ionic polysaccharide, or a flavorant compound to form a third mixture containing solid flavor particles at least partially coated with a first, second and optionally a third polymeric coating, and removing excess liquid from the second (or third) mixture to form coated solid flavor particles.

In another embodiment, there is provided a method of preparing coated solid flavor particles which comprises dissolving a first polymeric coating material in a liquid medium and if necessary, adjusting the pH of the resulting mixture to within a first predetermined range; dispersing a solid flavor particle in the medium, either as a dry particle or in the form of a dispersion, and if necessary adjusting the pH of the resulting mixture to within a second predetermined range; dispersing a second polymeric coating material in the medium and if necessary adjusting the pH of the resulting mixture to within a third predetermined range; optionally heating the resulting mixture at a temperature of up to the boiling point of water, preferably about 60° C to about 90° C, for about 10 minutes to about 180 minutes or more; refrigerating the mixture at a temperature of down to about the freezing point of the liquid mixture, preferably about 20° C to about 0° C, and more preferably from about 15° C to about 2° C for about 1 to about 48 hours, then removing excess medium to form dried coated solid flavor particles.

Once dried, the coated solid flavor particles may be easily incorporated into a variety of different palatable or edible products, such as chewable or non-chewable edible forms, due to the neutral esthetic color of the coated particles. For example, an original flavor having an undesirable physical color can be coated so that the coated solid flavor particle has a light beige color, making it more suitable for integration in neutral-colored edible systems.

Preferably, the coated solid flavor particles exhibit less than a 20% decrease in weight when heated to 250 °C in air, as measured by thermogravimetric analysis.

In another embodiment, the coated solid flavor particle can be used part of as a palatable or comestible product for animal or human consumption, and it may be incorporated into a consumer product for oral application, such as in the form of a tablet, stick, chewable gum, spongy material, foam, cream, pelleted material, or fiber, or a form suitable to be contained in a pouch, or combinations of these.

Such a product may have a first polymeric coating on the particle which is stable in the mouth for about 1 to about 20 minutes. The extraction mechanics of the flavor in the mouth may be altered by altering one or more of the following characteristics of the polymeric coatings, swelling behavior, visco-elasticity under physiological pH and temperature conditions, porosity, stability or rate of diffusion of ingredients under application of pressure by tongue or teeth or both, stability from dissolution upon attack from enzymes in saliva, or combinations of these. Also, one or more of the following characteristics of the polymeric coatings can be optimized for controlling the mouth feel of the edible product: slipperiness, sliminess, firmness, sponginess, stability or rate of diffusion of ingredients under application of pressure by tongue or teeth or both, stability from dissolution upon attack from enzymes in saliva, or combinations of these. These properties can be varied by selecting different coating materials for the first and second coating polymers, combining different coating materials, modifying the properties of coating materials, e.g., by crosslinking, or combinations of these.

Representative Particle Compositions

The coated particles may comprise (a) about 10% to about 90% by dry weight solid flavor particle, about 20% to about 1 % by weight of the first polymeric coating material, and about 50% to about 5% by weight of the second polymeric coating material, or (b) about 20% to about 80% by dry weight solid flavor particle, about 30% to about 1 % by weight of the first polymeric coating material, and about 60% to about 1 % by weight of the second polymeric coating material, or (c) about 40% to about 70% by dry weight solid flavor particle, about 15% to about 5% by weight of the first polymeric coating material, and about 40% to about 15% by weight of the second polymeric coating material.

It may also be advantageous to add some additional components or other additives during the processing to affect the "mouth feel," taste, texture, appearance, smell, flavor and flavor delivery and other attributes of the solid flavor particle. One or more other components may be included in the coatings, including, but not limited to, the following: gum arabic, flavorants, colorants, sweeteners such as xylitol, bulking agents, fillers, anti-adherent compounds, dispersing agents, moisture absorbing compounds, warming agents, cooling agents and film-forming agents. Other food ingredients such as starches, polyols, oils, lipids, waxes, fats, fatty acids, glycerides etc., may be also added to the coating to enhance the mouth feel of the finished, dried product. Additives, such as physiological cooling agents, throat- soothing agents, spices, warming agents, tooth-whitening agents, breath-freshening agents, vitamins, minerals, caffeine, drugs and other actives may be included in any or all portions of the coatings. Such components may be used in amounts sufficient to achieve their intended effects.

When the appropriate final ingredients and moisture content have been achieved, the mixture can be thoroughly homogenized or otherwise processed before it is dried, such as spray dried or freeze dried, under appropriate conditions to provide a micronized coated powder, comprising of individual dried particles, or agglomerations of particles. For example, the coated particles can be dried to a moisture content of less than about 15% by weight water, or if desired, to a moisture content between about 2 and about 5% by weight water.

Protein composition of the coated flavor particles may vary from about 20% to about 1%

(w/w) respectively. Carbohydrate composition may vary from about 50% to about 5% (w/w) respectively. The remaining constituents, apart from the flavor itself, may include without limitation acidifiers such as food grade citric acid or others known to the art, and salts. The particle size of the powder, if it is spray dried, can be anywhere from about 0.20 microns to about 2000 microns in size, preferably from about 0.25 micron to about 1000 microns, and more preferably from about 0.3 to about 250 microns, or from about 0.3 to about 100 microns. The coated particles described herein are such that they may have a net negative charge and a zeta potential value of about -5 mV to about -60 mV, more particularly from about to about -15 mV to about -40 mV, preventing excessive agglomeration of particles and a gritty texture.

The outermost layer may be preferentially optimized in terms of the swelling behavior and visco-elasticity under physiological pH and temperature conditions, for controlling the extraction kinetics of materials from the solid flavor particle. The release of selected compounds from the solid flavor particles may be triggered by simple diffusion into saliva, enzymatic digestion by enzymes occurring naturally in the saliva, and/or upon application of pressure by the tongue and teeth. For example, upon ordinary chewing or dipping of the product, the user will release flavorings or other attributes as hydration occurs.

The protein/polysaccharide coatings may be stable for a limited time, e.g., from about 10 to about 20 minutes under the influence of the enzymes in the saliva. The in-mouth time constant may be changed by selection of particular proteins/polysaccharides/ oligosaccharides in the coatings.

Coated flavor particles as described herein may be used in tobacco products and in non- tobacco orally enjoyable products. For example, such products may include palatable or comestible product comprising the coated particles in the form of a tablet, stick, chewable gum, spongy material, foam, cream, or fibrous or pelleted material, a form suitable to be contained in a pouch, or combinations thereof. Methods of Coating the Particle

In a particular embodiment of preparing coated solid flavor particles, the combining comprises adding either the solid flavor particles, or a dispersion of the solid flavor particles in a dispersing medium, to a dispersion of the first polymeric coating material in the first liquid medium to form a first mixture. The dispersing medium can be an aqueous medium, such as deionized water.

The formation of the coatings typically involves the gelling of the first and/or second polymeric coating material. This may be accomplished by, e.g., adjusting the pH of the coating material or the surrounding liquid medium or both, adjusting the temperature of the coating material or the surrounding liquid medium, or both, introducing gelation agents, or a combination of these. The methods used for each coating material may be different.

The starting solid flavor particle may be a negatively-charged particle. However, if it is not innately negatively-charged, the solid flavor particle may be treated by addition of appropriate reagents, for example bases such as sodium carbonate, sodium bicarbonate or sodium hydroxide (such as lye), to impart a negative or neutral charge to the particles before they are mixed with the first polymeric coating material.

The solid flavor particles can be dispersed in a dispersing medium, preferably an aqueous medium, comprising deionized water, to form a dispersion of the solid flavor particles. The solid flavor particles dispersed in the dispersing medium can be added to a solution of the first coating material in the liquid medium to form the first-coated particle dispersed in the liquid medium. Alternatively, the solid flavor particles can be added directly to the first coating material in the liquid medium, to form the first coated solid flavor particle dispersed in the liquid medium. The pH of either the dispersed solid flavor particles or the first coating material can be altered relative to the liquid medium , e.g., by adjusting the pH of the liquid medium, as desired to facilitate the electrostatic coating of the solid flavor particles by the desired coating. Suitable substances for adjusting the pH can be food-grade materials such as weak organic acids like acetic acid, adipic acid, fumaric acid, malic acid, lactic acid, tartaric acid, or gluconic acid, or mixtures of these, or by adding glucono delta lactone, or strong food grade hydrochloric acid, or by adding bases such as sodium carbonate, sodium bicarbonate or sodium hydroxide, or mixtures of these, for example.

The solid flavor particle coated with the first polymeric coating material is then contacted with a solution of a second polymeric coating material. Prior to adding the second polymeric coating material to the mixture containing the once-coated solid flavor particle, or before the once-coated solid flavor particle is added to the second polymeric coating material, the overall electrical charge of the first coating on the solid flavor particle can be altered by adjusting the pH of the liquid medium. Suitable substances for adjusting the pH are acids and bases, e.g., weak organic acids such as acetic acid, adipic acid, fumaric acid, malic acid, lactic acid, tartaric acid, gluconic acids and glucono delta lactone or strong food grade hydrochloric acid, or bases such as sodium carbonate, sodium bicarbonate or sodium hydroxide, for example. In one aspect, a first coating of a protein or protein hydrolyzate can be treated with an acid to facilitate electrostatic attraction of the second polymeric coating material.

The twice-coated solid flavor particle may be additionally coated with one or more of the substances used in the first and second polymeric coatings, with or without additional additives. The additional additives that may be employed to adjust the physiological characteristics of the final product and may be added just prior to the drying stage. For example, sweeteners like xylitol or solid sweeteners and solid flavors (encapsulated) can be added to the mix and homogenized further right before spray drying to avoid interacting with the gel formation. Other food ingredients such as starches, polyols, oils, lipids, waxes, fats, fatty acids, glycerides etc. may be also added to the formulation to achieve desirable characteristics in the final product. The coated particle may have a net negative or neutral charge. At the stage of the final coating, a gel may be formed from the coating by cross linking the carboxylic groups of the polysaccharides and the amino groups of proteins, or vice versa under processing conditions of about 60°C to about 90°C for about 1 to about 3 hours, and preferably about 60°Cto about 80°C for about 1 to about 1.5 hours. The gel may then be stabilized by refrigerating it at a temperature above the freezing point of the gel, and typically from about 20 °C to about 0 °C, or from about 15 °C to about 5 °C for about 1 to about 60 hours, and preferably about 12 to about 48 hours, before drying it.

Exemplary Method for Making Coated Particles

A solution containing about 0.5 to about 2% (w/w) protein in deionized water is prepared.

The ground solid flavor particles are dispersed in the protein solution. The pH is adjusted to within the range from about 3.5 to about 6 with citric acid, depending on the protein used. The selected second coating material is added to the mix in a powder or solution form and mixed thoroughly. The resulting mixture is heated at about 70 °C to about 80 °C for about 1 to about 2 hours, depending on the protein used. A salt may be added to the heated mix for proper gelation of the carbohydrate layer. Salts are preferably added to coacervates based on carrageenan, while pectin-based coacervate gels may or may not need any added salt. Suitable salts can include KCI, a mixture of KCI and calcium lactate, or simply calcium lactate, depending on the type of carbohydrate used. Other salts of bivalent metals such as calcium chloride or calcium citrate (including magnesium salts) can be used as well. The coacervate gel is preferably refrigerated for about 12 to about 48 hours before being spray dried.

FIG. 1 is a schematic depiction of a coated solid flavor particle as may be formed by the method described herein. In the center is a solid flavor particle, which in this case has an overall negative charge. It is surrounded or encapsulated by a first protein coating material, in this case, calcium caseinate. The protein layer is in turn surrounded or encapsulated by a polysaccharide, in this case kappa-carrageenan. Potassium ions have been added to assist in formation of the gel.

FIG. 2 is a schematic depiction of one embodiment of the method of forming the coated particle. A solid flavor particle 201 is combined with a first coating material 203 in a liquid medium to form a first mixture 205 of coated solid flavor particle. If needed, the first mixture 205 is treated to adjust the pH in 207 prior to the contact with the second coating material 209 to form a second mixture in 21 1. If desired, additional material 213 may be added to the second mixture to impart additional characteristics to the finished coated solid flavor particle, or to aid in gelation of the outer coating(s). The pH of the resulting material may be adjusted in 215 by addition of a suitable food-grade acid, base, or salt. Water may be added in 219, or removed prior to conditioning of the gel, and again to preparing the gel for the drying step 221. Once suitably dried, the finished coated particles 223 can be utilized as-is, or can be incorporated into other products. For example, one or more additional coatings may be added in order to manipulate the release profile and/or create a desired texture, such as a slimy, rough, and/or crunchy. EXAMPLE 1

A liquid berry flavor having a dark brown color was precipitated by water (with the solubility of water found to be less than 0.1 gm per 5 gm of liquid flavor) and the precipitate was separated from the liquid by centrifugation.

The subsequent coacervation was conducted under two different conditions: (a) using some of the supernatant (containing some flavors) along with deionized water in the coacervation formulation (Experiment # 32-2), and (b) wherein the supernatant was completely replaced by deionized water (Experiment # 32-1).

A complex coacervate was formed around the solid flavor particles with using soy protein and kappa-carrageenan, with appropriate pH adjustment of the solution. Gelation of the excess kappa-carrageenan and the coacervate layer took place via ionic crosslinking and hydrogen bonding at low temperature.

The firm coacervate gel was homogenized with excess deionized water into a thick slurry and spray dried at 177 °C inlet temperature and 107 °C outlet temperature in a Buchi B290 Lab mini Spray dryer, thus obtaining a very fine white powder with 60-65% (w/w) solid flavor.

FIG. 3 shows a thermogravimetric analysis (TGA) analysis of the samples from both the spray chamber and the collection chamber of the spray dryer. It can be seen that the unencapsulated precipitate undergoes substantial losses before 100 °C and disappears by 210°C, whereas the encapsulated samples show a flat weight loss profile until nearly 240 °C. The encapsulated samples clearly exhibit less than a 20% decrease in weight when heated to 250°C. The TGA process generally uses a ramp speed of 20 °C per minute.

The TGA data showed that the "(a)" samples (using a portion of the supernatant) from the spray chamber of the spray dryer had the best retention of flavor volatiles, followed by "(b)" samples from the spray chamber (not using supernatant), followed by samples from the collection chamber. The "(a)" samples from the spray chamber also exhibited a flavor profile of immediate and long lasting flavor lasting up to 16 minutes.

EXAMPLE 2

Further trials were conducted using liquid berry flavor originally in non-aqueous solvent and precipitated by water. The solid precipitate was encapsulated by the coacervation technique using rice protein and kappa-carrageenan, using equal parts deionized water and supernatant from the precipitation.

The various samples were as follows: "precipitated flavor" refers to precipitate obtained by adding water to the non-polar solvent in which the flavor is supplied; "36-1 CC" refers to encapsulated solid flavor obtained in the spray dryer collection chamber, using soy protein and carrageenan; "36-1 SC" refers to encapsulated solid flavor obtained in the spray dryer spray chamber, using soy protein and carrageenan; "36-5 CC" refers to encapsulated solid flavor obtained in the spray dryer collection chamber, using rice protein and carrageenan; "36-5 SC" refers to encapsulated solid flavor obtained in the spray dryer spray chamber, using rice protein and carrageenan; and "freeze dried encap." refers to encapsulated solid flavor dried by freeze drying method, using rice protein and carrageenan.

Encapsulated solid flavors were analyzed by gas chromatography (GC) as follows. One gram of dry encapsulated solid flavor was dissolved in 19 grams of pure ethanol under sonication at a temperature of 60 °C to extract the flavor in the organic phase. A second extraction of the same CC and SC samples in ethanol did not improve the extraction significantly.

A single peak area was monitored to estimate the approximate amount of flavor in each sample. All samples were normalized based on the flavor precipitate. Extraction for a single time in ethanol demonstrated that the freeze dried encapsulate retained more flavor than the spray dried versions, as shown in Table 1 below. CC and SC refer to collection and spray chamber samples, respectively. The major peak monitored by GC at retention time 4.37 min was compared to the intensity of the same peak in the pure precipitated flavor.

The encapsulated solid flavors were further analyzed by gas chromatograph mass spectrophotometry (GCMS) to identify flavor compounds. The relative amounts of flavor in each sample were compared on the basis of the raspberry ketone compound - this data is also shown in Table 1.

It is interesting to note that the SC samples were found to have more flavor compared to the CC samples, even though the SC samples were exposed to the high temperature of 175 °C for a longer time. The trend observed for CC, SC, and freeze dried encapsulated solid flavor samples is the same from both methods, with respect to the precipitate. It may be also noted that the 36-5 SC encapsulated solid flavor samples made with rice protein contained slightly more flavor compared to those made with soy protein (36-1 SC). Table 1. Relative amounts of flavor in encapsulated samples based on initial precipitate, based on peak areas from GC method and on GCMS analysis on the basis of raspberry ketone

From FIG. 4 it may be noted that the flavor precipitate loses all or nearly all of its volatile mass by about 210 °C, with the first 50% of weight loss being due to water present in the wet sample. The rice protein and carrageenan lose approximately about 80% and about 45% of their weights, respectively. Although the freeze dried sample contains more flavors, it also loses the volatiles much faster than the spray dried samples. There are two distinct regions in the weight loss curve of the freeze dried solid flavor: the first 60% probably corresponds primarily to flavor and the remaining 40% corresponding to the biopolymer or biopolymer bound flavor. The total loss of weight of freeze dried flavor is about 80%, much higher than the spray dried flavors, although the same formulation was been used in each, apart from the drying process. This difference between the spray drying treatment and the freeze drying treatment is surprising and unexpected.

Although the spray dried encapsulated solid flavors do not behave at all like the flavor precipitate or the freeze dried solid flavor, the weight loss curves of the spray dried encapsulated solid flavors are very similar to and between those of pure rice protein and kappa- carrageenan. This may be intuitively expected since the formulations contain both rice protein and kappa-carrageenan, the latter present in twice as much quantity as the former. The spray dried solid flavor curves indicate that either (a) the spray drying process may be enhancing the shell strength of the encapsulated particle compared to the freeze drying process, although the amount present in spray dried encapsulated samples may be smaller than that in the freeze dried encapsulated samples, and/or (b) the spray drying process results in a different mode of binding of the solid flavor to the biopolymers. From FIG. 5, the rate of change of weight with temperature is very sharp at 225 °C for kappa-carrageenan and a much broader peak at 325 °C for rice protein. The same curve for the pure, wet flavor precipitate demonstrates two broad peaks: one for water loss below 100 °C and the other at 200 °C for the flavor loss. It is again evident that the rate of change of weight of the freeze dried sample with temperature is very different from the spray dried samples; the maximum weight loss for freeze dried sample occurs at around 150 °C, followed by a small loss at 250 °C. The small peak at 250 °C is more characteristic of the small amount of bound carrageenan/flavor in the about 60% flavor sample. The 36-5 CC sample shows one sharp peak (more characteristic of kappa-carrageenan and bound flavor), a small shoulder (more characteristic of rice protein), and a third peak at around 500 °C. The 36-5 SC sample shows two less intense and broader peaks (characteristic of both carrageenan/flavor and flavor/rice protein). Probably in the spray dried samples, some part of the flavor is more tightly bound to both the polysaccharide and the protein to exhibit such trends, while more volatile and unbound part is lost during spray drying. The binding mechanisms in the CC and SC samples are slightly different and may explain the differences in the observed consumer perception.

FIGS. 6 and 7 indicate that the encapsulated samples with rice and soy protein behave very similarly, with the rice protein sample probably being better encapsulated and than the soy protein one. The rice protein encapsulated samples 36-5SC loses more flavor during heating compared to 36-1 SC, as seen from FIG. 6. This agrees with the GC and GCMS data which demonstrate that 36-5 SC contains more flavor than 36-1 SC. Also, in FIG. 7, the 36-5SC curve has two pronounced broad peaks compared to those of 36-1 SC.

EXAMPLE 3

A flavor panel testing in solid flavor particles encapsulated as described herein found that a sample from the spray chamber had excellent properties with regard to both immediate release and long lasting flavor. Samples of encapsulated solid flavors had flavor durations ranging from 9 to 20 minutes.

EXAMPLE 4

Three samples were prepared in a cGMP (current good manufacturing process) environment for flavor panel testing. The samples were as follows:

(1 ) 36-7 FD (freeze dried flavor) with 60.4% flavor solids encapsulated

(2) 36-8 CC (spray dried flavor in collector) with 62.17% flavor solids encapsulated

(3) 36-8 SC (spray dried flavor in spray chamber) with 62.17% flavor solids encapsulated

The flavor panel identified that 36-8 SC met the criteria for immediate and long lasting flavor, with a flavor duration of about 28 minutes.

Claims

1. A coated solid flavor particle comprising:

a base particle comprising a solid flavor particle;

a first polymeric coating material at least partially coating the base particle, said first coating material being selected from the group consisting of proteins, cationic polysaccharides or oligosaccharides, non-ionic polysaccharides or oligosaccharides, and mixtures of them; and a second polymeric coating material at least partially coating the first coating, said second coating material being selected from polysaccharides, proteins, a mixture of polysaccharides, a mixture of proteins, or a mixture of polysaccharides and proteins.

2. The coated particle of claim 1 wherein the solid flavor particle is coated with a hydrophobic coating. 3. The coated particle of claims 1 or 2, wherein the second polymeric coating material is anionic, Zwitterionic, or neutral.

4. The coated particle of any preceding claim, wherein the second polymeric coating material further comprises monovalent, divalent, or trivalent cations, comprising potassium, calcium, magnesium, iron or combinations thereof, or anions comprising chloride, citrate, lactate, acetate, or combinations thereof.

5. The coated particle of any preceding claim wherein the coated particle has a zeta potential value between about - 5 mV and about - 60mV.

6. The coated particle of any preceding claim wherein the first polymeric coating material has a molecular weight between about 2 KDaltons and about 1000 KDaltons.

7. The coated particle of any preceding claim wherein the second polymeric coating material has a molecular weight between about 5 KDaltons and about 1,000 KDaltons.

8. The coated particle of any preceding claim having a size of from about 0.20 microns to about 2000 microns. 9. The coated particle of any preceding claim wherein the base particle has a cross section less than about 1000 microns. The coated particle of any preceding claim comprising:

(a) a solid flavor particle in an amount of about 10 to about 90% by dry weight,

(b) a first polymeric coating in an amount of about 20% to about 1% by dry weight,

(c) a second polymeric coating material in an amount of about 50% to about 5% by

11. The coated particle of any preceding claim wherein the coated base particle has a moisture content of less than about 15% by weight.

12. The coated particle of any preceding claim having a net negative or neutral charge.

13. The coated particle of any preceding claim, wherein the particle exhibits less than a 20% decrease in weight when heated to 250°C, as measured by thermogravimetric analysis

14. A palatable or comestible product comprising one or more coated particles of any preceding claim.

15. A method for preparing coated solid flavor particles according to any preceding claim, the method comprising:

combining solid flavor particles and a first polymeric coating material in a liquid medium, wherein the first polymeric coating material adsorbs onto at least a portion of a surface of the particles to form a first layer,

mixing a second polymeric coating material with the liquid medium, wherein the second polymeric coating material adsorbs onto at least a portion of a surface of the first layer to form a second layer, and

spray-drying the particles to form coated solid flavor particles.