FOOD. Science. Technology. Quality

Food. SCIENCE. Technology. Quality

Food. Science. TECHNOLOGY. Quality

Food. Science. Technology. QUALITY

Authors

MAGDALENA MIKA, AGNIESZKA WIKIERA, KRZYSZTOF ŻYŁA

Title

Effect of extraction time and temperature on the content of catechins in white tea water extracts

Abstract

Non-fermented tea is a rich source of flavan-3-ols that have antioxidative properties. Recently, it has been proved that catechins containing gallic acid radical in their molecule are able to reduce intestinal absorbance of cholesterol and lipids from foods. The varying efficiency of the activity of catechin gallates is a consequence of their stereochemical structure. Catechin gallates, which belong to the (-) forms (2S, 3R) eliminate cholesterol from the micelles formed by bile acids in the most effective way. High temperature causes the epimerization of flavan-3-ols and the increase in the amounts of the (-) forms (2S, 3R). In this paper, the effect of temperature and time of extraction of dried white tea leaves was investigated on the total amount of flawan-3-ol, on the percent share of the (-) fraction of the forms (2S, 3R), and the percent share of catechins containing gallic acid radical in their molecule. It was showed that the composition of catechin preparations could be moulded by changing the conditions of tea extraction.

Keywords

flawan-3-ols, extraction, white tea, catechin gallates

Download