BACKGROUND OF THE INVENTION The present invention relates to methods of making chewing gum.

More particularly, the invention relates to a method of making chewing gum wherein melted gum base is added to a pre-existing mixture of water and plasticizer.

In conventional methods of making chewing gum, the gum base is typically added to the mixer first, whereupon it is heated and mixed. Normally, only after the gum base has been converted to a molten, flowing mass, are the other ingredients, such as bulking agents, plasticizers, water, flavor, etc., added to complete the chewing gum formulation. The mixing of this combination of chewing gum components then continues until they become well blended within each other and a homogeneous mass is produced.

One disadvantage of adding the sugar and other powdered ingredients to the molten gum base in the mixer is the fact that portions of the sugar can become compacted against the bottom or sides of the mixing chamber before being blended with the base. As the mixing continues, these layers of sugar and the like on the bottom or sides of the mixing chamber become more and more compacted by the mechanical action of the mixer. Often, these compacted layers will eventually break away from the bottom or sides of the chamber late in the mixing process, thereby producing lumps of sugar or "sugar spots"within the chewing gum product. Likewise, lumps can also occur when making sugarless gum with a sugar alcohol bulking agent.

U. S. Patent No. 4,806,364 to Kubota et al. discloses an alternative method where the mixing process is reverse. In this process the water or

liquid is mixed with powdered sweetener to form a sweetener matrix to which discrete particles of unmelted gum base are next mixed in. When used in sugarless gum, the procedure reduced but did not eliminate sorbitol spots.

Thus there is still a need for a process of making chewing gum which reduces or eliminates the occurrence of these sorbitol spots.

BRIEF SUMMARY OF THE INVENTION A method has been invented which reduces or eliminates the occurrence of sugar alcohol spots. The invention is a method of making a chewing gum composition comprising the steps of providing a mixture of water and plasticizer, providing a melted gum base, mixing the melted gum base with the mixture of water and plasticizer, and mixing a powdered bulk sweetener with the mixture of gum base, water and plasticizer to form the chewing gum composition. The liquids, especially if water is needed in the formula, is preferably added to an empty mixer. Molten base is added and then powdered bulking agents, and finally flavor and high-intensity sweeteners. This prevents or reduces sugar alcohol spots.

The present invention differs from conventional chewing gum making techniques in that, instead of adding the sweetener and other ingredients to a molten mass of gum base already in the mixer, water and a plasticizer such as glycerin are added to the mixer first and mixed if necessary, whereupon the gum base, in a melted form, is added to the mixer. In other words, the gum base is added to a pre-existing mixture of water and plasticizer and is added in melted form. The present invention also differs from the Kubota chewing gum making techniques in that the liquids are added first and mixed with the gum base and then sweeteners are mixed with the previous mixture.

This variation from the conventional practice has proven advantageous inasmuch as it effectively alleviates the problems of"sugar alcohol spots." That is, when the melted gum base is added to the water and plasticizer mixture, as opposed to the sweetener matrix being added to the gum base and the liquid added later, the method of mixing the components of a chewing gum formulation proceeds without the formation of compacted layers of sugar

alcohol and resultant sugar alcohol lumps inherent in conventionai mixing techniques. This procedure reduce the formation of these lumps by using the liquids early to make a more cohesive mixture.

A further advantage of the present invention is that it can be practiced using the same equipment as used for conventional methods. In particular, the mixing apparatus used in the preferred embodiment of the present invention can be identical to those used in conventional methods and no additional equipment is needed. Alternatively, the method can be used on continuous mixing equipment, such as an extruder.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a block diagram illustrating a preferred method of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION Unless otherwise specified, all percentages stated in the specification and claims are intended to refer to percentages by weight.

A chewing gum generally includes a water soluble bulk portion, a water insoluble chewing gum base portion, and one or more flavoring agents. The water soluble portion dissipates over a period of time during chewing. The gum base portion is retained in the mouth throughout the chewing process.

The insoluble gum base generally includes elastomers, elastomer plasticizers (resins), fats, oils, waxes, softeners and inorganic fillers. The elastomers may include polyisobutylene, isobutylene-isoprene copolymer, styrene butadiene copolymer and natural latexes such as chicle. The resins may include polyvinyl acetate and terpene resins. Low molecular weight polyvinyl acetate is a preferred resin. Fats and oils may include animal fats such as lard and tallow, vegetable oils such as soybean and cottonseed oils, hydrogenated and partially hydrogenated vegetable oils, and cocoa butter.

Commonly used waxes include petroleum waxes such as paraffin and microcrystalline wax, natural waxes such as beeswax, candellia, carnauba and polyethylene wax.

The gum base typically also includes a filler component such as calcium carbonate, magnesium carbonate, talc, dicalcium phosphate and the like ; softeners, including glycerol monostearate and glycerol triacetate; and optional ingredients such as antioxidants, color and emulsifiers. The gum base constitutes between 5-95% by weight of the chewing gum composition, more typically 10-50% by weight of the chewing gum, most commonly 20-40% by weight of the chewing gum, and most preferably about 28% to about 32% of the chewing gum.

The water soluble portion of the chewing gum may include softeners, bulk sweeteners, high intensity sweeteners, flavoring agents and combinations thereof. Softeners are added to the chewing gum in order to optimize the chewability and mouth feel of the gum. The softeners, which are also known as plasticizers or plasticizing agents, generally constitute between about 0.5-15% by weight of the chewing gum. The softeners may include glycerin, lecithin, and combinations thereof. Preferred chewing gum made by the present invention comprises between about 8% and about 12% glycerine.

Aqueous sweetener solutions such as those containing sorbitol, hydrogenated starch hydrolysates, corn syrup and combinations thereof, may also be used as softeners and binding agents in chewing gum.

Bulk sweeteners constitute between 5-95% by weight of the chewing gum, more typically 20-80% by weight of the chewing gum and most commonly 30-60% by weight of the chewing gum. Bulk sweeteners may include both sugar and sugarless sweeteners and components. Sugar sweeteners may include saccharide containing components including but not limited to sucrose, dextrose, maltose, dextrin, dried invert sugar, fructose, levulose, galactose, corn syrup solids, and the like, alone or in combination.

Sugarless sweeteners include components with sweetening characteristics but are devoid of the commonly known sugars. Sugarless sweeteners include but are not limited to sugar alcools such as sorbitol, mannitol, xylitol, hydrogenated starch hydrolysates, manitol, and the like, alone or in combination. Chewing gum made according to the present invention preferably comprises between about 48% and about 55% sugar alcool.

High intensity sweeteners may also be present and are commonly used with sugarless sweeteners. When used, high intensity sweeteners typically constitute between 0.001-5% by weight of the chewing gum, preferably between 0.01-1 % by weight of the chewing gum. Typically, high intensity sweeteners are at least 20 times sweeter than sucrose. These may include but are not limited to sucralose, aspartame, salts of acesulfame, alitame, saccharin and its salts, cyclamic acid and its salts, glycyrrhizin, dihydrochalcones, thaumatin, monellin, and the like, alone or in combination.

Combinations of sugar and/or sugarless sweeteners may be used in chewing gum. The sweetener may also function in the chewing gum in whole or in part as a water soluble bulking agent. Additionally, the softener may provide additional sweetness such as with aqueous sugar or alditol solutions.

The water content of chewing gum made by the present invention will preferably be between about 2.5% and about 3.5% of the composition and may be added by itself or as part of an aqueous sweetening solution.

Flavor should generally be present in the chewing gum in an amount within the range of about 0.1-15% by weight of the chewing gum, preferably between about 0.2-5% by weight of the chewing gum, most preferably between about 0.5-3% by weight of the chewing gum. Flavoring agents may include essential oils, synthetic flavors or mixtures thereof including but not limited to oils derived from plants and fruits such as citrus oils, fruit essences, peppermint oil, spearmint oil, other mint oils, clove oil, oil of wintergreen, cinnamon, anise and the like. Artificial flavoring agents and components may also be used in the flavor ingredient of the invention. Natural and artificial flavoring agents may be combined in any sensorially acceptable fashion.

Optional ingredients such as colors, emulsifiers, pharmaceutical agents and additional flavoring agents may also be included in chewing gum.

As seen in FIG. 1, the preferred method of the present invention for making a chewing gum begins by adding a quantity of water and plasticizer, such as glycerin and lecithin, to a mixer. The mixer is activated to mix the water and plasticizer. Alternatively the water and plasticizer can be pre-

mixed, and added to the mixer as a mixture. The color can be added to the mixer with the water and plasticizer initially, or can be mixed in later.

After the water and plasticizer are in the mixer and are mixed together, the gum base is added. The gum base is added in molten form. Preferably the gum base is melted in a separate piece of equipment and added in molten form to the mixer. If rework or recycle gum (gum that has previously been made and was an unusable portion after sheeting, sometimes referred to as "trim") is to be used in the formulation, it is preferably added at the same time the melted base is added to the mixer. The base is then mixed with the water/plasticizer mixture.

The powdered bulk sweetener, such as sorbitol, mannitol, maltitol or xylitol, is next added to the mixer. Flavor can be added at this point, or even later. It is preferred to add flavor late in the mixing process because most flavors are volatile. The powdered bulk sweetener is mixed into the mixture of gum base, water and plasticizer.

If a high-intensity sweetener is used, it is preferably added after the bulk sweetener. Alternatively, the high-intensity sweetener may be added prior to mixing in the molten gum base. The entire contents of the mixer are blended to form a generally homogeneous mixture, and is then discharged from the mixer and formed into gum products using conventional equipment and techniques.

The mixer used in the method of this invention can be that type which is standard in the industry. In particular, the mixer will typically have a sigma or other type blade. The mixer will typically also be capable of heating the mixing chamber by a jacket or other means.

The preferred embodiment of the invention includes the following steps. First, all the liquids (except the flavor) are deposited in an empty mixer and mixed for about 30 seconds to about 4 minutes, more preferably for about 1 minute. Next, molten base (and trim if used) is added to the liquid mixture and mixing is continued for about 2 to about 7 minutes, more preferably for about 2 minutes. Next the sorbitol or other powdered bulking agent and flavor are added and mixed for about 5 to about 10 minutes, more preferably for

about 5 minutes. The mixer is stopped and high-intensity sweeteners are added and mixed for about 2 to about 7 minutes, more preferably for about 2.5 minutes. After this the mixer is stopped and the mass discharged.

The following examples are provided by way of explanation and illustration, and are not to be interpreted as limiting the scope of the present invention as defined in the appended claim.

EXAMPLES Gum Formula Example 1: INGREDIENT PERCENT SORBITOL 53. 0 BASE 30. 0% GLYCERIN 8.0% WATER 3.9% FLAVOR 2.5% ENCAPSULATEDHIGH-2.0% INTENSITY SWEETENERS COLOR 0.5% LECITHIN 0. 1%

Mixing Procedure Using Gum Formula in Conventional Prior Art Mixing: The following procedure was used to prepare 446 kg of sugarless tab gum (included in weight--70 kg of previously mixed gum, also known as trim).

The hot water circulating system connected to the mixer jacket was started to heat the mixer walls to the proper temperature : 125°F + 5°F (52°C 3°C).

1) At T=0 minutes the mixer was started and base, lecithin, and color were added to the mixer.

2) At T=4 minutes the sorbitol and flavor were added.

3) At T=8.5 minutes the mixer was stopped and 70 kg trim, glycerin, and water were added.

4) The mixer was started again and mixed until T=10.5 minutes.

5) At T=10.5 minutes the mixer was stopped and encapsulated high-intensity sweeteners were added.

6) The mixer was started again and mixed until T=15.0 minutes.

7) The batch was then completed and discharged from the mixer.

Sorbitol spots were noticeably present on the resulting gum mass.

Mixing Procedure Using Gum Formula and the Invention: The following mixing procedure according to the invention was used to prepare 446 kg of sugarless tab gum (included in weight--70 kg of previously mixed gum, also known as trim).

The hot water circulating system connected to the mixer jacket was started to heat the mixer walls to the proper temperature : 125°F _ 5°F (52°C + 3°C).

1) At T=0 minutes color, lecithin, water and glycerin were added to the mixer.

2) At T=1 minute The mixer was stopped and 70 kg of trim and melted gum base was added.

3) The mixer was started again.

4) At T=1 minute 45 seconds the sorbitol and flavor were added to the mixer.

5) At T=6 minutes 45 seconds mixing time, the mixer was stopped and the encapsulated high-intensity sweeteners were added.

6) The mixer was started and mixed until T=10 minutes 15 seconds.

7) The batch was then completed and discharged from the mixer.

The inventor observed no sorbitol spots in this batch.

Without wishing to be bound by theory, the inventor feels the sorbitol spots are reduced/eliminated because the glycerin interacts with the water molecules, which decreases the interaction between the water and the sorbitol. Because the water is not available to directly affect the sorbitol, the sorbitol has a chance to mix in with the ingredients without clumping. Other plasticizers such as glycerol triacetute, propylene glycol, glycerol monosterate, coconut oil and mixtures thereof may provide the same function.

A wide range of changes and modifications to the embodiments of the invention described above will be apparent to persons skilled in the art. For example, the invention can be used in continuous gum mixing processes.

Also, while the invention is particularly advantageous for sugarless gums, the

same mixing procedure could be used when making gums using sugars instead of sugar alcools.

It will be appreciated that the addition of some other ingredients, process steps, materials or components not specifically included will have an adverse impact on the present invention. The best mode of the invention may therefore exclude ingredients, process steps, materials or components other than those listed above for inclusion or use in the invention.

It should be appreciated that the compositions and methods of the present invention are capable of being incorporated in the form of a variety of embodiments, only a few of which have been illustrated and described above.

The invention may be embodied in other forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive, and the scope of the invention, therefore, is indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.