VARIATIONS IN THE AMOUNTS OF INDIVIDUAL FLAVANOLS IN A RANGE OF GREEN TEAS

The concentrations of the major tea flavanols in nine green teas from China and Japan have been investigated. Results show that epi-gallocatechin (EGC) is the most prevalent flavanol and not epi-gallocatechin gallate (EGCG) as previously thought. Studies of the equilibrium behaviour of extraction of tea flavanols and caffeine into aqueous media at 80-degrees-C and 60-degrees-C for one of the teas, Sen Cha Uji Tsuyu, indicate that extraction efficiencies are similar to that for extraction of soluble components from black teas. These studies also support the idea of EGC being the flavanol with the highest concentration. This is of relevance to the current interest in tea flavanols as antimutagenic agents in the treatment of cancers. From the flavanol content results there appears to be a correlation between the amount of flavanol and the price of the tea. It is possible that this might be used to aid the pricing of green teas at auction.