Antimutagenicity and catechin content of soluble instant teas

Constable, N. Varga, J. Richoz and RH. Stadler Nestec Ltd Research Centre, Vers-Chez-les-Blanc, PO Box44, Ch-1000 Lausanne 26 Switzerland, March 1996 Issue Mutagenesis.

The antimutagenic properties of soluble instant teas were examined using the bacterial Ames assay. Inhibition of the numbers of revertants induced from a number of known mutagens indicates that aqueous extracts of instant teas have antimutagenic activity and antioxidative properties, and can inhibit nitrosation reactions. Despite a significant reduction in the amounts of major green tea catechins, quantified using reversed-phase HPLC with electrochemical detection, no differences in antimutagenicity were observed between the instant teas, a black fermented tea and a green tea. Oxidation of polyphenolic compounds which occurs during the production of instant tea does not therefore decrease the antioxidant, free radical scavenging and antimutagenic properties. This suggests that catechins are not the only compounds responsible for the protective effects of teas.