Thaumatin

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Thaumatin is a low-calorie (virtually calorie-free) protein sweetener and flavour modifier. The substance is often used primarily for its flavour modifying properties and not exclusively as a sweetener.

Totally natural, thaumatin is metabolised by the body as any other dietary protein.

The thaumatins were first found as a mixture of proteins isolated from the katemfe fruit (Thaumatococcus daniellii Bennett) of west Africa. Some of the proteins in the thaumatin family (Simple Modular Architecture Research Tool accession #SM00205) are natural sweeteners roughly 2000 times more potent than sugar. 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 usage levels.

Thaumatin is highly water-soluble, and stable to heating and stable under acidic conditions. Thaumatin production is induced in katemfe in response to an attack upon the plant by viroid pathogens. Several members of the thaumatin protein family display significant in vitro inhibition of hyphal growth and sporulation by various fungi. The thaumatin protein is considered a prototype for a pathogen-response protein domain. This thaumatin domain has been found in species as diverse as rice and Caenorhabditis elegans.

Within west Africa, the katemfe fruit has been locally cultivated and used to flavor foods and beverages for some time. The fruit's seeds are encased in a membranous sac, or aril, that is the source of thaumatin. In the 1970s, the Talin Food Company of Merseyside, in the United Kingdom, began extracting thaumatin from the fruit and selling it under the trade name Talin. In 1990, researchers at Unilever reported the isolation and sequencing of the two principal proteins found in thaumatin, which they dubbed thaumatin I and thaumatin II. These researchers were also able express thaumatin in genetically engineered bacteria.

Thaumatin has been approved as a sweetener in the European Union (E957), Israel, and Japan. In the United States, it is a Generally Recognized as Safe flavoring agent (FEMA GRAS 3732).

[edit] References

J.D. Higginbotham, in Alternative Sweeteners, L.O. Nabors and R.C. Gelardi, eds., Marcel Dekker, Inc., New York, 1986.
Witty,M. and Higginbotham,J.D. (Editors). Thaumatin. CRC Press 1994. ISBN 0-8493-5196-0.