Thaumatin

Thaumatin is a naturally occurring sweet-tasting protein extracted from the fruit of the katemfe plant, Thaumatococcus daniellii, native to West Africa. On a molar basis it is around one hundred thousand times sweeter than ordinary table sugar, though its taste builds slowly and leaves a lingering, licorice-like aftertaste at higher concentrations, so it is used more often as a flavor modifier and enhancer than as a direct replacement for sugar. Thaumatin is an approved sweetener in the European Union, Japan and Israel, and in the United States it holds generally recognized as safe status as a flavoring agent rather than as a sweetener in its own right.