Analysis of 3″-Methyl-epigallocatechin gallate in Sichuan tea varieties resources

3″-Methyl-epigallocatechin gallate(EGCG3″ Me) in the young tea leaves of 70 major tea varieties resources in Sichuan were analyzed using HPLC. The results revealed that Shucha 5,Jinguanyin,Chengxi 11 were found to contain higher levels of EGCG3″Me(>10 mg/g). The EGCG3″Me levels of different positions of tea line Shucha 5 ‘five and a bud' shoots from spring to autumn were also analyzed. The results showed that the contents of EGCG3″ Me presented first an increasing and then a decreasing trend with the leaf maturity.Compared with the same leaf order,EGCG3″Me contents were increasing. The second leaf in autumn were the highest,the first to the fourth leaves were more than 10 mg/g. The fresh tea leaves in autumn of Shucha 5 were processed to four different types of teas,The EGCG3″Me levels of green tea and yellow tea were the highest,similar to fresh tea leaves,followed by oolong tea. However,black tea do not contain detectable EGCG3″ Me.The content of EGCG3″ Me increased distinctly during withering. Based on these results,a better way to produce tea leaves rich in EGCG3″Me was proposed,which includes picking fresh tea leaves with two or three leaves and a bud in autumn,processed to green tea or yellow tea,modest spreading(mild withering) before processing.