Europaisches Patentamt 19 European Patent Office Office europeen des brevets © Publication number: 0 427 796 B1 12 EUROPEAN PATENT SPECIFICATION @ Date of publication of patent specification : © int. ci.5: A23G 3/30, A23L 1/236, 29.09.93 Bulletin 93/39 A23L 1/22 (2j) Application number : 90900603.3 (22) Date of filing : 17.11.89 © International application number : PCT/US89/05159 @ International publication number : WO 90/06062 14.06.90 Gazette 90/14 © CHEWING GUM CONTAINING HIGH-POTENCY SWEETENER PARTICLES WITH MODIFIED ZEIN COATING. © Priority: 02.12.88 US 279215 (56) References cited : WPI, FILE SUPPLIER, Derwent Publications @ Date of publication of application : Ltd., London, GB; & JP-B-45012759 22.05.91 Bulletin 91/21 © Proprietor : WM. WRIGLEY JR. COMPANY © Publication of the grant of the patent : 410 North Michigan Avenue 29.09.93 Bulletin 93/39 Chicago Illinois 60611 (US) @ Designated Contracting States : @ Inventor : COURTRIGHT, Steven, B. AT BE CH DE FR GB IT LI LU NL SE 1629 Brummel Evanston, IL 60202 (US) (56) References cited : Inventor : BARRETT, Kevin, F. EP-A- 0 067 595 7202 Western Avenue EP-A- 0 320 522 Darien, IL 60559 (US) WO-A-89/03170 US-A- 29 682 © Representative : Baverstock, Michael George US-A- 3 262 788 Douglas et al US-A- 3 753 739 BOULT, WADE & TENNANT 27 Furnival Street US-A- 3 922 354 London, EC4A 1PQ (GB) US-A- 3 928 633 US-A- 3 956 507 US-A- 3 962 468 US-A- 4 004 039 US-A- 4 049 706 US-A- 4 139 639 US-A- 4 230 687 US-A- 4 269 860 US-A- 4 384 004 US-A- 4 384 005 US-A- 4 495 213 US-A- 4 497 835 US-A- 4 517 214 US-A- 4 554 167 US-A- 4 556 565 CO US-A- 4 568 560 CO US-A- 4 579 747 o> US-A- 4 597 970 US-A- 4 634 593 h- CM Note : Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of shall be filed in written reasoned statement. It shall not be deemed to have been LU opposition a filed until the opposition fee has been paid (Art. 99(1) European patent convention). Jouve, 18, rue Saint-Denis, 75001 PARIS EP 0 427 796 B1 Description The present invention relates to methods for producing chewing gum. More particularly, the invention re- lates to methods for producing chewing gum containing high-potency sweetener particles which have been 5 coated with zein to enhance shelf-life stability and/or delayed release. In recent years, efforts have been devoted to controlling the release characteristics of various ingredients in chewing gum. Most notably, attempts have been made to delay the release of sweeteners and flavors in various chewing gum formulations to thereby lengthen the satisfactory chewing time of the gum. Delaying the release of sweeteners and flavors can also avoid an undesirable overpowering burst of sweetness or flavor 10 during the initial chewing period. On the other hand, some ingredients have been treated so as to increase their rate of release in chewing gum. In addition, other efforts have been directed at protecting high-potency sweeteners within the chewing gum formulation, to thereby increase the shelf-stability of the ingredient, i.e. the protection against degradation of the high-potency sweetener over time. 15 Forexample, U.S. Patent No. 4,597,970 to Sharmaetal., teaches a process for producing an agglomerated sweetener wherein the sweetener is dispersed in a hydrophobic matrix consisting essentially of lecithin, a gly- ceride, and a fatty acid or wax having a melting point between 25 and 100°C. The method disclosed uses a spray congealing step to form the sweetener-containing matrix into droplets followed by a fluid bed second coating on the agglomerated particles. 20 U.S. Patent Nos. 4,515,769 and 4,386,106, both to Merrit et al., teach a two step process for preparing a delayed release flavorant for chewing gum. In this process, the flavorant is prepared in an emulsion with a hydrophyllic matrix. The emulsion is dried and ground and the particles are then coated with a water imperme- able substance. U.S. Patent No. 4,230,687, to Sair et al., teaches a process for encasing an active ingredient to achieve 25 gradual release of the ingredient in a product such as chewing gum. The method described involves adding the ingredient to an encapsulating material in the form of a viscous paste. High shear mixing is used to achieve a homogeneous dispersion of the ingredient within the matrix which is subsequently dried and ground. U.S. Patent No. 4,139,639, to Bahoshy et al., teaches a process of "fixing" aspartame by co-drying (by spray drying or fluid bed coating) a solution containing aspartame and an encapsulating agent, such as gum 30 arabic, to thereby surround and protect the aspartame during storage in the gum. U.S. Patent No. 4,673,577 to Patel teaches a process wherein high-potency sweeteners are encapsulated with food grade shellac. U.S. Patent No. 4,384,004, to Cea et al., teaches a method of encapsulating aspartame with various en- capsulating agents, including zein, by various encapsulation techniques, such as spray drying, in order to in- 35 crease the shelf-stability of the aspartame. U.S. Patent No. 4,863,745 assigned to the assignee of the present invention, discloses a novel process of applying zein as a second coating to high-potency sweeteners for chewing gum. EP-A-320522 (relevant to the present application under Article 54(3,4)EPC) relates to a process for treating an ingredient so that it will exhibit a controlled release when incorporated in chewing gum. According to the 40 process a quantity of a powdered ingredient is mixed with an agglomerating agent and a limited quantity of a solvent for the agglomerating agent. EP-A-0067595 relates to the encapsulation of the artificial sweetener L-aspartyl-L-phenylalamine methyl ester (APM) with a coating material for subsequent use in food products. The encapsulated APM is found to exhibit shelf stability when incorporated into food products. 45 JP-B-45012759 relates to coatings of zein, hydroxypropylmethylcellulose and solvent for pharmaceutical products. Zein is a protein of the prolamine class which is derived from corn. In the past, zein has found many uses as a coating material. Forexample, the co-pending application reports the surprising result of increased sta- bility of dipeptide sweeteners in aldehyde flavor containing chewing gums when the sweetener particles re- 50 ceive a coating of zein as a second coat. Unfortunately, a potential disadvantage of using zein as a coating material for high-potency sweeteners in chewing gum is that zein tends to form a relatively hard and crunchy coating. As a consequence, zein coated particles above a certain size can impart a grainy texture, or grittiness, to the chewing gum. Because the zein coating is relatively frangible, any grittiness generally passes quickly as the zein is broken into smaller pieces 55 by chewing. However, even a momentary grittiness in the chewing gum can lead to customer dissatisfaction. Although much of the problem with grittiness may be overcome by using smaller particles, it is noted that the particle size is important in determining the exact release profile of coated high-potency sweetener. Thus, while the desire to overcome grittiness may dictate the use of smaller zein coated particles, a certain delayed 2 EP 0 427 796 B1 release profile may dictate the use of larger particles. The present invention is a method for producing a chewing gum with a zein coated delayed release high- potency sweetener. In accordance with the invention, the zein coating is modified so as to be softer so that 5 the sweetener particles are less crunchy and thus less perceptible in the chewing gum. Briefly stated, the process begins by mixing a quantity of zein, a solvent for the zein, and a water soluble modified cellulose compound between 5 and 40 percent by weight of the zein together to form a modified zein solution. This modified zein solution is applied to a high-potency sweetener and then dried to produce the de- layed release sweetener particles coated with between 1 and 15 percent by weight zein. These particles are 10 then added to a chewing gum formulation. In accordance with a first preferred method of the present invention, the high-potency sweetener is the dipeptide sweetener generally known as aspartame. Also in this preferred embodiment, the zein is dissolved in water having a pH of between 11.5 and 12.1 and contains about 13 weight percent zein. Hydroxypropyl me- thylcellulose is added to this solution at about 2 percent by weight of the solution, i.e. 15 percent by weight of 15 the zein. This aqueous zein and HPMC solution is added in an amount between 15 and 45 percent by weight of the damp mix created with the aspartame. As a result, the final zein coated aspartame is preferably between 4 and 25 weight percent zein, and between 0.2 and 1 0 percent HPMC. In this embodiment, the chewing gum made is a mint flavored gum with between about 0.1 and 0.5 weight percent of the coated aspartame. In accordance with a second preferred method of the present invention, the zein is disolved in ethanol to 20 between about 10 and 50 percent by weight of the solution.