Abstract

COMPARATIVE STUDY OF ANTI-OXIDANT ACTIVITY OF GREEN, BLACK, WHITE AND OOLONG TEA

Dr. Harsimran Singh Bhalla*, Dr. Jagdeep Kaur, Anmol Arora and Nitish Kumar

Abstract

The present study was investigated to find out anti-oxidant activity of different types of tea by using in vitro DPPH assay and to compare the % inhibition and IC50 values of varieties of tea with standard ascorbic acid. Moreover, phytochemical screening has also been carried out to evaluate the presence and absence of flavonoids, alkaloids, phenols, tannins, proteins and amino acids. The study clearly indicated that the extract of different tea possesses excellent anti-oxidant potential. Ranking of antioxidant properties of tea extracts were found to be green tea > Oolong tea > black tea> white tea. For all four teas, antioxidant property of green tea was significantly higher than extracts of other tea on the basis of % inhibition and IC50 value. The IC50 of green tea, ascorbic acid, oolong tea, black tea and white tea were found to be 2.285, 3.447, 3.607, 4.177 and 7.046 respectively. Hence, it has been proposed that higher polyphenolic content may be the key mechanism for higher antioxidant property compared to other types of tea.

Keywords: Tea, oxidative stress, green tea, reactive oxygen species, ascorbic acid.