Quality, antioxidant activity and composition of Indian black teas.

A comparative study was undertaken to determine the difference in quality, antioxidant activity, and mineral content of northern and southern Indian tea varieties. The results showed that the antioxidant activity, theaflavin and thearubigin content, color particle size and total soluble solids influence the tea leaf and tea dust. Assam leaf showed higher values for all the physico-chemical properties followed by Darjeeling leaf. In addition, the mineral composition of the tea infusion was also influenced. The preparation method, including the amounts of tea and water used, infusion time was shown to be a major determinant of the component concentrations of tea beverages as consumed. An illustration of the variation introduced by these varieties of tea is provided by comparing solids, caffeine, minerals and antioxidant activity of black teas available locally.