Comparative Analysis of Black Tea Metabolites from Different Origins Based on Extensively Targeted Metabolomics

In order to explore the origin differences of black tea metabolites, the metabolites in black tea produced in Fu 'an and Youxi of Fujian province were compared and analyzed by using sensory evaluation method and extensive targeting metabolomic determination method of ultra-performance liquid chromatography-mass spectrometry (UPLC-MS/MS). The results showed that, Fu'an black tea mainly tasted of “mellow and soft”, while Youxi black tea of “mellow and sweet”. A total of 937 metabolites including of flavonoids, phenolic acids, lipids, organic acids, amino acids and their derivatives were identified by metabonomics in the black tea of the two regions, through the principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLS-DA) could significantly distinguish different producing area of black tea, and identified 410 species of metabolites with significant difference. The relative content of 291 different metabolites in Youxi black tea was higher than that of Fu 'an black tea, among which Astragalin, EC, L-glutamine, L-aspartic acid, L-lysine, L-tryptophan, L-glutamic acid, chlorogenic acid, phenethylamine, vitexin-2''-O-rhamnoside might have important contributions to the formation of different taste and quality of black tea from the two regions. Metabolic pathway analysis showed that the metabolism levels of amino acids and flavonoids of black tea between the two places were significantly different, which might be the reason for the difference in the taste and quality of black tea between the two places. The research would provide a theoretical basis for the identification of tea origin.