Thaumatin.
THAUMATIN is an intensely sweet-tasting protein (on a molar basis about 3,000 times as sweet as sucrose and found in the West African shrub Thaumatococcus Danielli. The thaumatin were first found as a mixture of proteins isolated from the katemfe fruit Thaumatococcus Danielli in West Africa It has become an increasingly mainstream natural low glycemic index sweetener alternative to many artificially-produced low-calorie sweeteners on the market. Thaumatin has such a high potency sweetness relative to sugar that only a tiny amount is needed to sweeten foods. The amount of calories added to a food when thaumatin is used as a sweetener is negligible. Thaumatin is also used to enhance flavors and mask bitterness. Although quite sweet, its sweetness builds slowly. It is metabolized by the body similar to any other dietary protein.