Gum base is the non-nutritive, non-digestible, water-insoluble masticatory delivery system used to carry sweeteners, flavors, and any other substances in chewing gum and bubble gum. It provides all the basic textural and masticatory properties of gum.
The actual composition of gum base is usually a trade secret. The FDA allows 46 different chemicals under the umbrella of “gum base.” The chemicals are posted on their website. These chemicals are grouped into the following categories.
- Natural coagulated or concentrated lattices of vegetable origin: These include many of the resins such as chicle that were traditionally chewed as gum. It also includes natural waxes like beeswax and latex (natural rubber).
- Synthetic coagulated or concentrated lattices: These include petroleum derived polymers such as paraffin and petroleum waxes. It also includes polymers such as butadiene-styrene, vinyl acetate, and polyethylene which were more recently designed and are utilized to maximize elasticity and incorporate other components of the gum base as well as flavors and sweeteners in their chemical matrix.
- Plasticizing materials (softeners): These materials generally help to emulsify various chemical components that do not always bind to each other. They are generally medium-sized molecules and are frequently esters of tree resins and rosins.
- Terpene resins: This specific subcategory is not fundamentally different from materials in the first two categories except it is a specific substance that can be produced both naturally and artificially.
- Antioxidants: The most common antioxidant in gum, BHT functions by scavenging free radicals (which spoil food) and sequestering them behind its sterically hindering tert-butyl groups.
Gum bases for chewing gum are different from those for bubble gum. A bubble gum base is formulated with the ability to blow bubbles; it contains higher levels of elastomers or higher molecular weight polymers for this purpose. Gum bases for non-acid flavored gum use calcium carbonate as a filler, while gum bases for acid flavored gum use talc as a filler, since acids can react with calcium carbonate to produce Carbon Dioxide gas, which is undesirable.
Bubble gum usually contains 15-20% gum base, while chewing gum contains 20-25% gum base and sugar-free chewing gum contains 25-30% gum base.
Researchers at the University of Illinois at Urbana-Champaign and at Wm. Wrigley Jr. Company are studying the possibility of making gum base with biodegradable zein (corn protein).
Large chewing gum manufacturers generally produce their own gum base in-house while small chewing gum producers usually buy gum base from third-party suppliers.