CA2029297A1 - Chewing gum with self stabilized dipeptide sweeteners - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
Chewing gum is made with, as an intense sweetener, at least one dipeptide sweetener wherein the peptide sweetener is used in the form of a self-stabilized composition by being spheronized into a dense, non-porous granule of substantially spherical shape falling within a narrow particle size distribution.

Description

~ 4~ l7 l CHEWING GUM WITH SELF STABILIZED DIPEPTIDE SWEETENERS
BACKGROUND OF THE INVENTION
_ FIELD OF THE INVENTION
The present invention relates to sugarless chewing 5 gum compositions which contain at least one dipeptide sweetener. The sweetener is preferably aspartame (L-aspartyl-L-phenylalanlne methyl ester), and it is used in the form of a self stabilized composition which is formed by spheronizing the dipeptide into a dense non-porous granule 10 form which has a substantially spherical shape and which shape falls within ~ narrow particle size distribution.
DESCRIPTION OF THE PRIOR ART
PCT Application WO89/00819 discloses the preparation of a self stabilizing form of dipeptide sweetener 15 which is specifically designed for use in baking and other high temperature cooking applications. This dipeptide sweetener compos~ilion is prepared in the form of granules of substantially uniform spherical shape that fall within a narrow particle size distribution range. The granules are 20 designed to disintegrate under the elevated temperature conditions used in baking and other high temperature food cooking operations (i.e., about 350 - 400F).
The inventors of PCT WO 89/00~19 were apparently of the opinion that the successful use of their granules depended on an intermolecular hydrogen bonding effect that was only achieved or enhanced at elevated baking temperatures, noting in part that This unexpected stabilization is believed to be a result of the above discussed binding effects such as the inter- and intra-molecular hydrogen bonding of aspartame at very high concentrations. For example, the solubility of aspartame increases with temperature to 2- ~2~2~ ~

l well above 10% during the baking process. At a high concentration such as that created by ~he formatlon of the dense, uniformly shaped spherical particles, the intermolecular hydrogen-bonding effects among aspartame molecules may be so profound that it enhances aspartame's baking stability. As the baking process proceeds, a small amount of water ls able to enter the granule and is gradually absorbed. The spherical granule dissolves and the APM becomes a highly concentrated solution that diffuses into the batter. At such a high concentration, however, the intermolecular hydrogen bonding may be maintained and, as a result, the dipeptide does not cyclize or degrade. This effect is not observable in dilute aspartame solutions and the degradation rate of aspartame in dilute solution follows pseduo-first order kinetics which is independent of aspartame concentration.
An object of the present invention is to employ the dipeptide based spheroidal granules disclosed in PCT WO 89/00819 in in an application which does not require the use of high cooking or baking temperatures.
A further object of the present invention is to employ such dipeptide based spheroidal shaped granules in sugarless chewing gum as a source of an intense sweetener therefor.
A still further object of the present invention is to employ such peptide based spheroids in a sugarless chewing gum formulation which would be unstable to conventional aspartame.
SUMMARY OF THE PRESENT INVENTION
It has now been found that the non-porous peptide based spheroidal shaped granules disclosed in PCT WO B9/00819 can be successfully used in sugarless chewing gum, which is made at relatively low temperatures, as a source of dipeptide , -3- ~2~

l sweetener for such chewing gum products if the granules are used according to the chewing gum formulation and processing conditions described hereinafter.
It was totally unexpected that the dipeptide based 5 spheroids remained stable in a chewing gum formulation heretofore unstable to aspartame due to free moisture present in the formulation. The chewing gum of this invention comprises suficient moisture to degrade any unstabilized dipeptide sweetener present, a gum base, bulking agent and a formulated amount of dipeptide sweetener, said dipeptide sweetener being in a self-stabilized form to resist degradation by moisture by being spheronized into a dense, non-porous granule of substantially spherical shape falling within a narrow particle size distribution range, said self-stabilized form of aspartame being effective to stabilize the dipeptide sweetener when said chewing gum is stored at 30 relative humidity and 105F for at least 28 days so that at least 70% by weight of the original formulated amount of aspartame is recoverable.
DESCRIPTION OF THE DRAWINGS
Figure 1 is a cross-sectional view of one embodiment of a processor utilized to manufacture the granular products of the present invention and showing a modification of an Aeromatic Prototype 1 Roto Processor/
Spheronizer with elevated spoke-like ridges on the bottom disk.
Figure 2 is a cross-sectional view of a second embodiment of a processor utilized showing a modification of a Aeromatic Prototype 1 Roto Processor/Spheronizer with elevated spoke-like ridges on the bottom disk.

~2~?~ ~

l Figure 3 is a cross-sectional view of a third embodiment showing a modification of the Aeromatic Prototype 1 Roto Processor/Spheronizer with a fluidizing circulation aid.
Figure 4 is a cross-sectional view of a spheronizer of the present invention in operation showing a flow of needle-shaped crystalline aspartame powder as it is compacted into dense non-porous spherical granules of uniform size distribution.
DESCRIPTION OF THE PREFERRED EMBODIMENT
-Granular Spheroidal Shaped Peptide Sweetener The non-porous granular spheroidal shaped peptide sweetener used in the present invention is made as disclosed in PCT WO 89/00819, with additional technology relative to such spheroidal materials as may be disclosed herein. The contents of PCT WO 89/00819 relative to such manufacturing procedures are incorporated herein by reference.
The peptide materials utilized herein are those dipeptides which are commonly used as intense sweeteners in food products, including chewing gum products. These dipeptides include the dipeptides themselves, as well as the food-grade salts and complexes thereof. The preferred dipeptide is aspartame (L-aspartyl-L-phenylalanine methyl ester). The present invention is particularly directed to transforming needle or rod shaped crystals of such dipeptides into the granular, spherical shaped sweetener products used in the present invention.
The aspartame products used in the present invention are dense granular particles of substantially uniform spherical shape within a narrow particle size distribution. These granules can be formed with or without , ~5~ 2~3~J2 l additional stabllizing or sustained release agents. The sustained release effect can be further enhanced through the addition of a hydrophobic binding material about the granules which, due to their uniform spheroidal shape, can be evenly coated to obtain optimum coating protection.
If a matrix is first prepared comprising the dipeptide and either starch, polydextrose, cellulose or other food polymers prior to granule formation, the matrix is made up of between 10-100% of the dipeptide sweetener. The matrix may also contain 0-20% of a buffer composition or weak acid to maintain the granular pH in the range of 3.0-5.0 during usage. This pH range is optimum for aspartame's wet or solution stability. If the granule is then encapsulated with a fat, protein or carbohydrate, the dipeptide sweetener should comprise approximately 5-80% of the entire granule by weight.
~ .ccor~ing to PCT WO 89/00819, a particle size range for satisfactory stability was found to exist between 10 and 80 U.S. standard mesh, preferably 20-50 U.S. standard mesh.
The sustained-release delay functions can be further enhanced by the deposition of a protective binder coating about the spherical particles after spheronization. Suitable binder coating materials are hydrophobic compounds such as fat, protein, corn starch, insoluble fibers and other materials such as talc, alkali earth metal stearate such as magnesium stearate or calcium stearate, titanium oxide, precipitated calcium carbonate, zinc oxide, colloidal silica, shellac, polyethylene, waxes, cellulose and its derivatives, zein, and the like.

1 The granules of the present invention are non-porous dense granules, which are uniform spherical particles falllng within a narrow particle size distribution. The granules employed Eor a particular application should not 5 vary more than approximately +20 mesh between the smallest and the largest.
The granules of the present invention can be made by a number of high shear-energy and roll compaction granulators commercially available in the art. These granulators produce non-spherical granules which may exhibit the improved self-stabilizing effects of the present invention. These granules are dense and non-porous and may be suitable for certain applications, but are not the preferred embodiment for use in making the granules employed in the present invention.
The preferred process for preparing the self-stabilize~ ~i.peptide granule of the present invention utilizes the inner chamber of the insert of an Aeromatic Prototype 1, Size 2 Roto-processor by Aeromatic Inc., Towaco, N.J. For purposes of this application, this device shall be referred to by its generic name, a spheronizer, which is essentially a large cylindrical chamber with a rotating disk bottom. The walls of the cylinder actually bend inwards from the circumference of the disk towards the center at about a 20 angle similar to an upside down cone or funnel.
Commercial spheronizers of conventional design are not efficient in making uniform sized non-porous spherical granules of the present invention, par~icularly at production volumes. Therefore, the spheronizers utilized herein preferably include one or more of the following features modifying the commercial spheronizer design, -7- ~ 2~

1 (1) The rotating disk at the bottom of the cyllnder has elevated spokes, equidistant Erom each other that radiate outward from near the center of the disk.
(Fig. 1) (2) The edge of the rotating disk is curved upwards. (Fig. 2) (3) Adjustable flanges along the inner wall act as a circulation aid for the fluidized powder. (Fig. 3) Any powdered dipeptide sweetener may be processed according to the spirit and scope of the present invention.
Whereas aspartame, due to its present popularity within ~he food industry is the preferred embodiment, it is to be understood that the following teaching utilizes this dipeptide as the one of choice.
Dry APM powder is deposited into the cylinder of the spheronizer and initially falls onto the rotating disk.
Rotation of the ~isk hurdles the particles against the walls of the cylinder and creates a centrifugal swirling turbulence or flow (Fig. 4) of the dipeptide particles that results in bombardments of the particles against themselves and the walls of the spheronizer.
During the process, a solvent is sprayed onto the fluidized powder to wet it uniformly. The preferred solvents are water, alcohols, such as methyl, ethyl and propyl alcohols, and their mixtures. At a proper wetness, the particles start to form uniform size spherical granules as a result of the bombardments against other particles and the cylinder walls caused by the centrifugal and the tangential fluidizing forces of the rotating disk and, due to the 3o -8~ ~2~

1 solvent effects such as dissolution and binding. The size of the spherical particles grows continuously and uniformly as additional crystals are compacted. The particle growth rate is controllable by adjusting the disk's rotatlon rate and/or the solvent spray rate.
The formation and growth of the spherical particles can be accelerated using one or more air jets directed at the fluidized wet powder. Desired particle size can be determined visually at which time the wet spheronized sample can be dried in a fluid bed drier.
The design of the commercially avallable Aeromatic roto-processor cannot specifically perform the granulation process desired for the present invention. It is designed for liquid and suspension spray-coatings under gentle fluidizing conditions. During normal operation, the position of the rotating disk bottom is lowered to have a circular opening through ~lhich wet powder is thrown out of the inner chamber by the force of the rotating disk. An outer chamber has an upward-flow of hot air which dries, lifts, and dumps the powder back into the inner chamber through its top opening for more spray-coating. ~here are two positions at which the circular disk can run with respect to the bottom of the spheronizer. Under normal conditions the disk is lower than the bottom of the chamber whereby an opening exists between the inner and outer chambers. During the operation of the present process, the disk is raised to the same plane of the inner chamber bottom, thereby preventing any APM
particles from falling through the bottom to the outer chamber.
3o 2~2~2~'7 1 Since the rotating disk of the spheronizer has limited fluidizing power, manual scraping is needed to keep the wet powder and granules circulating or fluidizing, especially near the end of a granulation run. An unmodified Aeromatic Prototype l size 2 Roto-Processor insert was initially used to make the granular samples as aisclosed in PCT WO 89/00819. It apparently had barely enough fluidizing power to granulate 2 kg APM powder per run. A trial run as disclosed in PCT WO 89/00819 to granulate 4 kg APM powder using larger capacity equipment with an insert o the Aeromatic Prototype 2 size 2 apparently failed to keep wet powder fluidized. Therefore, to permit unattended operation and for increased production capacity, the earlier described modifications of the spheronizer or the equipment are apparently needed to increase its mechanical fluidizing power.
Instead of having an outer chamber, a Glatt roto-processor provides an upward air current along the inner wall to assis~ the rotating disk to fluidize the spheronized APM
powder. However, this pneumatic turbulence significantly decreases the particle bombarding effect which is utilized by the method as disclosed in PCT WO 89/00819 to make non-porous spherical granules. In addition, the pneumatic turbulence dries wet APM particles and breaks up already formed granules which are counterproductive actions. The Glatt eguipment was tested as disclosed in PCT WO 89/00819 and failed to make the granules used in the present invention.
The dense aspartame particles of spherical shape and uniform size produced for use in the present invention can be coated with one or more binding layers of hydrophobic materials by fluidized-bed coating methods known in the art.

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If a fat or lipid type compound is used as a coating, a hot melt of the fat is sprayed onto the dense spheres in a cold fluidized bed. Polymer coatings are applied by spraying solutions containing the pol~mer and a binder such as ~vicel, a microcrystalline cellulose, onto the aspartame granules ln a hot or warm fluidlzed bed. Cooked or gelatinlzed starch, Methocel, (methylcellulose, Dow Chemical Co.) and zein can also be used as binders with the polymer coating.
The coating materials and processes of U.S. Patent 1 No. 4,384,004 (Lea et al.) may also be used.
Chewinq Gum Products The preferred chewable products in which the sweetener composition of the present invention may be used are the comestible and semi-comestible types of products and particularly chewing gum products.
The chewing gum compositions contemplated by the present ~nventi~n comprise all types of sugarless chewing gums and chewing gum formulations known to those skilled in the art, including the regular gum, and the bubble gum types.
2 Typical chewing gum compositions comprise a chewing gum base, a modifier, a bulking agent (sorbitol), and one or more other additives such as glycerine, fillers, flavoring agents, colorants and antioxidants. The modifying agents are used to soften, plasticize and/or compatibilize one or more of the components of the gum base and/or of the formulation as a whole.
The compositions of the present invention Gontain amounts of water which, in the absence of this invention, would have a destabilizing effect on the aspartame used in O such compositions. These destabilizing amounts of water will vary from product to product depending on the amount of 2 ~

aspartame being used and on the presence or absence of an adverse heat history for the product. Chewing gu~. products made according to the present invention may have a moisture content in the range of about 2 to 8% and preferably of about 3 to 7%.
Based on the e~perience of the present inventors, it has been found that when used according to the teachings of the present invention, and particularly in chewing gum products, aspartame can be stabilized against decomposition for extended periods of shelf storage time to such an extent as to allow for the use, over the normal shelf life of such products, about 20 to 50~, and preferably about 30 to 40%, less of the aspartame that would be needed, in the absence of the stabilization of the present invention, in order to provide for the desired levels of sweetness attainable from the aspartame during the course of such shelf life. The recoverable amounts of aspartame, as reported herein, are analytically determined by the high performance liquid chromatography method. From a commercial point of view, the recovery of the aspartame is achieved in the mouth of the user of the comestible product in which it is employed.
The chewing gum products of the present invention would have the following general formulation:

WEIGHT % OF COMPONENT

gum base 15 to 35 20 to 30 gum base modifier 0 to 5.0 0.3 to 3.0 bulking agent 0 to 90 40 to 65 granular aspartame of the present invention 30 fillers 0 to 35 0 to 30 glycerine 0 to 30 0 to 15 Total 100 100 2~2~ ~

GUM BASE
The composition of the gum base will vary depending on whether the gum base is to be used in a cAewing gum product which is to be a regular, or non-bubble gum product or a bubble gum product. For use in making a bubble gum or regular chewing gum product, the following gum base formulations may be used in accordance with the present invention:

WEIGHT % OF COMPONENT IN GUM BASE FOR:
COMPONENT BUBBLE GUM PRODUCT REGULAR GUM PRODUCT
BroadPreferred BroadPreferred Ranqe_Ranqe RangeRan~e masticatory material 8-22 9-18 8-25 9-18 plasticizer for masticatory material 5-3510-20 2-30 8-20 hydrophilic detackifier 0-30 4-10 5-3510-25 20 plaSticizer for hydrophilic detackifier 0-14 0-8 1-15 3-12 wax 3-15 5-10 4-20 8-15 mineral filler 0-35 10-22 0-35 15-30 antioxidant 0-0.10.05-0.09 0-0.10.03-0.09 Total 100 100 3o -13- ~2~7 l The masticatory substances are elastomeric materials which may be synthetic or natural in origin. The masticatory substances of synthetic origin would include styrene-butadlene copolymer (SBR), butyl rubber (which is isobutylene-isoprene copolymer) and polyisobutylene. The natural masticatory substances should include chicle, crown, gum, nispero, balato, jetulong, pendare, perillo, niger, gutta, tunlc, leche caspi, sorva and gutta hank kang.
The plasticizer for the masticatory substance should have minimal tackifying properties and will preferably comprise a hydrogenated ester gum, that is a glycerol ester of hydrogenated resin and/or dimerized ester gum. However, other resins may be employed such as pentaerythritol ester gum, polymerized ester gum, polyterpene resin and ester gum.
The hydrophilic-type detackifier is a material which will absorb saliva and would include vinyl polymers having a mclecular weight of at least 2000, and preferably of about 2000 to 80,000 or more, such as polyvinyl acetate, polyvinyl butyl ether and copolymers or vinyl esters and vinyl ethers. The plasticizers for the hydrophilic type detackifiers would include lanolin, stearic acid and sodium stearate.
The plasticizers for the hydrophilic type detackifiers would include triacetin, acetylated glycerides and other flavor adjuvants such as ethyl acetate and triethyl citrate.
The waxes which are used serve primarily as compatibilizers. Examples of appropriate waxes are paraffin wax, candelilla wax, carnuba wax, microcrystalline waxes and polyethylene waxes.

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2 ~ 2 ~ ~

1 The mineral fillers would include calcium carbonate, titanium dioxide, talc, alumina, magnesiu~
hydroxide, dicalcium phosphate, tricalcium phosphate and mixtures thereof, although calcium carbonate is not preferred 5 when saccharin acid is used.
The gum base may also include a softening agent and lubricant combination which may comprise one or more hydrogenated vegetable or animal fats.
The gum base may also include about 0 to about 2-0%, and preferably about 0.1 to about 0.7% of an emulsifier to impart hydrophilic properties to the gum base. Examples of such emulsifiers include phosphatides such as lecithin, in addition to that used in the gum base modifier, and mono- and diglycerides of these fatty acids and mixtures thereof with glyceryl monostearate being preferred.
In addition, the gum base may include antioxidants such as butylated hydroxy toluene, butylated hydroxy anisole and propyl gallate.
The chewing gum compositions of the present invention are sugarless. The sugar substitute used in the compositions of this invention include non-sugar sweeteners.
The amount of non-sugar sweetener which can be used can range from 0 to about 2 weight percent of the final composition.
At least one of such sweetener is employed.
The intense sweeteners employed in the present invention are dipeptide sweeteners. The preferred dipeptide sweetener is the granular aspartame of the present invention.
Other intense sweeteners which may be employed in combination with the granular aspartame sweetener of the present invention include poorly water soluble, as well as 1~--1 water-soluble sweeteners, such as the free acid form of saccharin, sodium, calcium or ammonium saccharin salts, dihydrochalcones, glycyrrhizin, dipotassium glycyrrhizin, glycyrrhizic acid/ammonium salt, talin, acesulfame K, as well 5 as Stevia rebandianna (Stevioside), Richardella dulcifica (Miracle Berry), Dioscoreophylim cumminisii (Serendipity ~erry), free cyclamic acid and cyclamate salts and the like, or mixtures of any two or more of such materials.
The sugarless chewing gum of this invention will 10 contain sorbitol, xylitol, mannitol or other polyhydric alcohols as the bulking agent. However, other bulk sweeteners commonly used in chewing gums can be used. These include natural sugars (sucrose, dextrose, lactose, maltose, and xylose), hydrogenated starch hydrolysates (including 15 hydrogenated corn syrup and hydrogenated glucose syrup) as well as the sugar alcohols, and mixtures thereof.
~ he che~Jing gum made by this invention can also contain glycerine, fillers, conventional FD&C and natural coloring agents. The flavoring which can be included in the chewing gum compositions made according to this invention can comprise one or more natural and/or synthetic flavors and/or oils derived from plants, leaves, flowers and fruit.
Representative flavors and oils of these types include acids such as adipic, succinic and fumarlc acid; citrus olls such as lemon oil, orange oil, lime oil and grapefruit oil; fruit essences, such as apple essence, pear essence, peach essence, 3o -16- 2~ 7 1 strawberry essence, apricot essence, raspberry essence, cherry essence, plum essence, and pineapple essence;
essential oils such as peppermint oil, spearmint oil, mixtures of peppermint oil and spearmint oil, clove oil, bay 5 oil, anlse oil, oil of nutmeg, oil of sage, oil of bitter almonds, cassia oil and methylsalicylate (oil of wintergreen). Various synthetic flavors, such as those for a mixed fruit, may also be incorporated in the chewing gum with or without conventional preservatives.

The chewing gum products of the present invention are prepared by first separately preparing the gum base. To then prepare the sugarless chewing gum formulation, the gum base for the product is melted, at a temperature about 190 to 15 250F, and the other components of the composition are added thereto. The resulting composition is uniformly admixed.
This takes abo~; , to 7 minutes for each of the respective components used in commercial sized batches of these formulations. Each of the components is usually separately 20 added to the formulated composition and uniformly mixed in before the next component is added. All of the admixing operations are conducted at temperatures in the range of about 112 to 185F, and preferably about 125 to 180F for a total mixing time, at such temperatures, of about 10 to 25 25 minutes. The operations do not have to be conducted under anhydrous conditions in preparing the compositions of the present invention, and any amounts of moisture that are normally present in the raw materials that are used in the compositions of the present invention do not usually have to 30 be removed therefrom either prior to, or during the formulating process.

-17- 2~2~ f l The~dipeptide sweetening ingredients of the present invention are preferably added at the end of the formulation process to avoid any premature mastication type action thereon which might otherwise occur during the mixing operations.
The liquid sorbitol has a solids content of about 70%. The solid sorbitol is a high (80%) gamma form having a M.P. of 99C. The aspartame, when used at a 0.10 to 0.50 weight % formulation level, is usually admixed, lO proportionally, with about 10 to 50 pounds of the formulated amount of powdered sorbitol before being added to the mixing vessel. When being admixed in and further processed the aspartame in the compounded product is usually exposed to a heat history of 120 to 140F for up to about 20 to 30 15 minutes.
The H2O content reported in the Example is a calculate~ amount. The actual water content is about 0.2 to 0.5% higher than the calculated value since additional amounts of water enter the formulated product from the other 20 components of the formulation and from the ambient atmosphere. The formulation of the Examples are formed into chewing gum products and then subjected to accelerated aging tests conducted at 105F and at 30 relative humidity. The recoverable aspartame contents of the products was 25 periodically determined analytically by high performance liquid chromatography. Samples were thus analyzed for recoverable aspartame (APM) contents first at zero time, i.e., within 48 hours after the product was first made, and prior to its being subjected to any accelerated aging, and 30 then at various intervals, after 8 to 42 days of accelerated aging.

-18- ~2~2~ 7 l The test ~ormula~ions are prepared using production plant procedures. These procedures are as follows:
PRODUCTION PLANT PROCEDURE
1. Into a pre-warmed sigma bladed mixer add 5 molten gum base. The gum base temperature is between 150-200F, and preferably between 170-190F.
2. With the blades of the mixer operating, and the temperature in the cited range, the lecithin is added and the mixing is continued for one minute.
3. Add 1/3 of the bulk sweetener (sorbitol powder) and mix for two minutes, or until homogeneous.

4. Add 1/2 of the sorbitol solution mix for two minutes, or until homogeneous.
S. Add 1/3 of the sorbitol powder and continue 15 mixing for two minutes.
6. The liquid flavor is then added and mixing is continued for on~ r,linute.
7. Add the second 1/2 of the sorbitol solution and mix for two minutes.
8. Add the remaining 1/3 of the sorbitol powder and the aspartame. Prior to production of the batch, the aspartame is premixed with approximately 1/3 of the sorbitol powder. Continue mixing for two minutes, or until the batch is homogeneous. The final gum temperature is approximately 112F.
9. The gum is removed from the mixer and conditioned at 70F/ambient R.H. prior to forming.
10. The gum is rolled and scored into a stick configuration. Mannitol is applied to the surface of the scored gum to prevent surface adhesion. The gum is then transferred into fin-seal foil pouches and sealed.

-19- 2~2~

l EXAMPLES l_AND 2 A sugarless bubble gum IExample 1) is prepared using the procedure described above and utilizing the self-stabilized APM spheroids of this invention. Polyiso-5 butylene rubber is used as the gum base. The Example 2formulation is a sugarless regular (non-bubble gum) chewing gum. The formulations have a % by weight for each component as follows:

lO Gum Base 25.5G 2,.50 Plasticizer2.00 -----Sorbitol Powder 47.50 47.50 Sorbitol Solution 22.10 22.10 Mannitol ----- 2.00 Lecithin 1.00 1.00 Flavor 1.50 1.50 l~ Color 0.15 0.15 APM Spheres0.25 0.25 Calculated Water 6.00 6.00 When subjected to accelerated aging tests, the above chewing gums will produce the following recoverable 20 levels of APM.
% APM RECO~ERABLE AFTER DAYS INDICATED
28 days 35 days 42 days Example 178% 74% 65%
Example 275% 72% 62%
These results will indicate the high recoverable levels of APM that can be obtained over extended periods of time with the self-stabilized APM spheres. On the other hand, when chewing gum products made under comparable 30 conditions with 0.1 to 0.3% conventional, unencapsulated, and unstabilized APM and a water content of about 2 to 8% no more than 50% of the formulation amount of APM is still recoverable after 35 days of the accelerated aging test conditions.

-20- 2~ 7 1 While this invention has been described by reference to the above eY~ample, it ls intended to be limited only by the scope of the appended claims.

Claims (11)

1. A chewing gum composition comprising sufficient moisture to degrade any unstabilized dipeptide sweetener present, a gum base, bulking agent and a formulated amount of dipeptide sweetener, said dipeptide sweetener being in a self-stabilized form to resist degradation by moisture by being spheronized into a dense, non-porous granule of substantially spherical shape falling within a narrow particle size distribution range, said self-stabilized form of aspartame being effective to stabilize the dipeptide sweetener when said chewing gum is stored at 30° relative humidity and 105°F for at least 28 days so that at least 70%
by weight of the original formulated amount of aspartame is recoverable.

2. A chewing gum composition as claimed in Claim 1 in which said dipeptide sweetener comprises aspartame.

3. A chewing gum composition as claimed in Claim 2 in which said aspartame is admixed with a binding agent thereby forming a matrix.

4. A chewing gum composition as claimed in Claim 3 in which said binding agent is selected from the group consisting of polymeric carbohydrates, proteins, fats, corn starch, insoluble fibers, talc, alkali earth metal stearate, titanium oxide, calcium carbonate, zinc oxide, colloidal silica, shellac, polyethylene, waxes, cellulose and its derivatives and zein.

5. A chewing gum composition as claimed in Claim 3 in which said matrix further comprises an acid and a buffering agent.

6. A chewing gum composition as claimed in Claim 4 in which said matrix is coated with a hydrophobic coating.

7. A chewing gum composition comprising 2 to 8%
by weight moisture, 15-35% gum base, 0 to 5% gum base modifier, 0-90% bulking agent, 0-35% filler, coloring agent, flavoring agent, and a formulated amount of aspartame sweetener, said aspartame being in a self-stabilized form of spheronized, dense, non-porous granules of substantially spherical shape falling within a narrow particle size distribution range of between 10 and 80 U.S. standard mesh, said self-stabilized form of aspartame being effective to stabilize the aspartame when stored at 30° relative humidity and 105°F for 28 days so that at least 70% by weight of the original formulated amount of aspartame is recoverable, said formulated amount of aspartame being about 20 to 50% less than the amount which would have been needed to recover an equal % of aspartame in the absence of the self stabilization.

8. The chewing gum composition of Claim 7 in which the bulking agent is a polyhydric alcohol, natural sugar, hydrogenated starch hydrolysate, or mixtures thereof.

9. The chewing gum composition of Claim 8 containing sorbitol.

10. The chewing gum composition of Claim 9 containing hydrogenated starch hydrolysate.

11. The chewing gum composition of Claim 9 containing 0-30% glycerine.