Analysis of naturally occurring 3″-Methyl-epigallocatechin gallate in 71 major tea cultivars grown in China and its processing characteristics

Naturally occurring 3″-Methyl-epigallocatechin gallate (EGCG3″Me) in the young tea leaves of 71 major tea cultivars grown in China and its processing characteristics were analyzed. The results revealed that four tea cultivars were found to contain higher levels of EGCG3″Me (>10 mg/g). There were significant regional characteristics in the distribution features of these Chinese tea cultivars rich in EGCG3′′Me. The levels of EGCG3″Me were the highest in the third leaf among the tea leaves from different positions of young shoots with a bud and five leaves. The content of EGCG3″Me increased distinctly during the withering process, whereas the content declined drastically during the fermentation process. Based on these results, a better way to produce tea leaves rich in EGCG3″Me is proposed, which includes picking standards for fresh tea leaves and for processing methods. This study provides a solid foundation for the further exploitation and utilization of natural EGCG3″Me in the food and pharmaceutical areas.