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.
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 a gas, polyvinyl acetate (carpenter's glue), 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.
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.
Composition and manufacture
The exact composition of gum bases is usually a trade secret, but generally consists of ingredients from the following categories:
- Elastomers: provide the elasticity or bounce, and can be natural latexes (e.g. couma macrocarpa (also called leche caspi or sorva), loquat (also called nispero), tunu, jelutong, or chicle which is still commercially produced), or synthetic rubbers (e.g. styrene-butadiene rubber, butyl rubber, polyisobutylene).
- Resins: provide a cohesive body or strength, and are most often glycerol esters of gum, terpene resins, and/or polyvinyl acetate.
- Waxes: act as softening agents and are most usually paraffin or microcrystalline wax.
- Fats: behave as plasticizers and mainly come from hydrogenated vegetable oils.
- Emulsifiers: help to hydrate, the most common being lecithin or glycerol monostearate.
- Fillers: impart texture and the most commonly used are calcium carbonate or talc.
- Antioxidants: protect from oxidation and extend shelf-life; the most common type is BHT.
Old gum bases were based on either natural elastomers such as latexes, vegetable gums like chicle, spruce gum, and mastic gum, or alternatively on waxes, e.g. paraffin wax and beeswax, but today synthetic rubbers are preferred.
Formulation and Production of Chewing and Bubble Gum, edited by Doug Fritz, pp 93–118, Olivias's Publications Ltd, London, UK, 2006