INHIBITION OF SALIVARY AMYLASE BY BLACK AND GREEN TEAS AND THEIR EFFECTS ON THE INTRAORAL HYDROLYSIS OF STARCH

Tea decoctions prepared from a number of black and green teas inhibite d amylase in human saliva. Black teas gave higher levels of inhibition than green teas, and removal of tea tannins with gelatin led to the l oss of inhibitory activity from all decoctions. Streptococcal amylase was similarly inhibited by tea decoctions. Fluoride was without effect on amylase. Since salivary amylase hydrolyzes food starch to low mole cular weight fermentable carbohydrates, experiments were carried out t o determine whether tea decoctions would interfere with the release of maltose in food particles that became entrapped on the dentition. Sub jects consumed salted crackers and rinsed subsequently for 30 s with b lack or green tea decoctions, or water. Maltose release was reduced by up to about 70% after rinsing with the teas. Black tea decoction was significantly more effective than green tea, in agreement with the in vitro data. The observations supported the hypothesis that tea consump tion can be effective in reducing the cariogenic potential of starch-c ontaining foods such as crackers and cakes. Tea may reduce the tendenc y for these foods to serve as slow-release sources of fermentable carb ohydrate.