Identification of Chinese green tea (Camellia sinensis) marker metabolites using GC/MS and UPLC-QTOF/MS

Tea is one of the most widely consumed aromatic beverages in the world because of its taste and flavor, as well as due to many potential health beneficial properties. Metabolomics focuses on an in-depth analysis of all metabolites in living organisms. In this study, 29 primary metabolites and 25 secondary metabolites were identified using GC/MS and UPLC-QTOF/MS, respectively. Further, PCA analysis showed conspicuous discrimination for the ten varieties of green tea with metabolite profiling. Among them, organic acids, amino acids, flavan-3-ols, and flavonol glycosides varied greatly through checking the VIP values of the PLS-DA model. Moreover, the intrinsic and/or extrinsic factors characterizing each type of green tea were also discussed. The chemical component marker derived here should be used as an important detection index, while evaluating the tea quality, as well as while establishing the tea quality standard.