Widely targeted metabolomics analysis of different Wuyi Shuixian teas and association with taste attributes

There are two major types of Wuyi Shuixian teas with distinct flavor properties in the market: regular Shuixian, and Laocong Shuixian that is produced from old tea plants with higher sale price. However, the chemical composition difference between these two types of Shuixian teas is still unclear. In this study, the widely targeted metabonomics and sensory evaluation were carried out to investigate the metabolite profiles and the flavor properties of Laocong and regular Shuixian tea samples. The results of organoleptic evaluation showed the Laocong Shuixian teas achieved dramatically higher total scores of sensory quality than that of regular Shuixian, and the sour palate of Laocong Shuixian tea was much lower than that of regular Shuxian. A total of 692 metabolites were identified by using metabolic determination, 43 of which were different metabolites in Laocong Shuixian teas discriminated from regular Shuixian. The contents of caffeic acid, kaemperfin, genistin, quercetin 3-glycosides and p-coumaric acid-O-glycoside were abundantly present in regular Shuixian tea. The analysis on different metabolites and taste attributes showed that phenolic acidic compounds were the major contributors to the sour taste of regular Shuixian. This study interpreted the chemicals underlying the different taste properties of Laocong and regular Shuixian teas.