Thaumatin

Thaumatin (also known as talin) is a low-calorie sweetener and flavor modifier. The protein is often used primarily for its flavor-modifying properties and not exclusively as a sweetener.

The thaumatins were first found as a mixture of proteins isolated from the katemfe fruit (Thaumatococcus daniellii) (Marantaceae) of West Africa. Although very sweet, thaumatin's taste is markedly different from sugar's. The sweetness of thaumatin builds very slowly. Perception lasts a long time, leaving a liquorice-like aftertaste at high concentrations. Thaumatin is highly water soluble, stable to heating, and stable under acidic conditions.