Study of metabolites dynamic variation during vine tea (Ampelopsis grossedentata) processing by untargeted metabolomics

Vine tea is a paramount Chinese tea with a wide variety of health benefits. The tea quality would be affected by tea processing procedures. It is essential to unravel the dynamic variation of metabolites during tea processing. To interpret the dynamic changes, the metabolic profiling was characterized by ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) with 1890 metabolites. Furthermore, the chemometrics methods were implemented to explore key metabolites to clarify the dynamic changes during processing. Four pair-wise models were developed with R2Y higher than 0.990. Fifteen key metabolites were explored during manufacturing process. Fixation stage was closely associated with generation of bioactive compounds of dihydromyricetin (DIH). DIH had highly significant correlation with key metabolites of 2-hydroxy lignoceric acid, lamioside, and 3-o-methylgallic acid according to mantel test. The results provide valuable information on dynamic changes of metabolites during processing in tea.