Abstract: In this study, the metabolic profiles of fresh leaves (F), two indoor withered samples for 29 h (W) and 53 h (P) respectively were investigated by HILIC-QqQ MS based targeted metabolomics. Totally 111 metabolites were detected in the QC sample, including 47 amino acids and their derivatives, 29 nucleic acid metabolites, 12 vitamins and coenzymes, 17 sugar metabolites and 6 glycerophospholipid metabolites. Compared with the fresh leaves (F), 39 and 41 metabolites were significantly increased in withered samples W and P, with 35 overlapped metabolites. On the other hand, 9 and 11 metabolites were dramatically reduced, with 8 overlapped metabolites. The metabolite changes suggested that the cell membranes were damaged, DNA and RNA were degraded, amino acids derivatives were significantly increased and glucose metabolism was abnormal. Furthermore, according to the variations of metabolite contents and compositions, the marker metabolites of the withered leaves were identified which could reflect the physiological states of cell membrane, nucleic acid and glucose metabolism. Eventually, based on the characteristic changes in amino acids and nucleotides, the necessities of characterizing the flavor properties of amino acids and their derivatives as well as exploring the possibility of using metabolic profiling as white tea withering standards were proposed.

Key words: white tea, withering, targeted metabolic profiling