Comparative study on the content levels of the major chemical constituents of Pu-erh tea among different producing areas

In order to provide preliminary scientific basis for the identification of producing areas of Pu-erh tea products,the content levels of the major chemical constituents as well as the volatile compounds in Pu-erh tea products obtained from three major producing areas,i.e. Lincang city,Xishuangbanna city and Pu-erh city,were analyzed and compared in this study. Results showed that the levels of the major chemical constituents including water extracts,total flavonoids,total free amino acids,and tea pigments(theabrownins,theaflavins,thearubigins) were observed to have significant differences(p<0.05) among Pu-erh teas produced in different areas, and the levels of tea polyphenols and gallic acid were found to have slight difference( p > 0. 05).Moreover,significant differences were observed within the levels of some volatile compounds,such as 3,4-dimethoxytoluene,1,2,3-trimethoxy-5-methyl-benzene,nerol,nerolidol,citral,3,4,5-trimethoxy-benzaldehyde,dimethyl itaconate,and tetrahydroactinidiolide,among Pu-erh teas produced in different areas,and the principal components analysis could effectively separate the Pu-erh tea samples produced in different areas.