Abstract: In order to understand the dynamic changes of non-volatile metabolites in Xinyang Maojian tea during processing, the samples of Xinyang Maojian tea processing were systematically analyzed by non-targeted metabolomics technology using Camellia sinensis vs. Xinyang Quntizhong as raw materials. The results showed that a total of 1 000 non-volatile metabolites were comparatively identified during the processing of Xinyang Maojian tea, and the multivariate statistical analysis showed that non-volatile metabolites changed significantly after fixing of Xinyang Maojian tea. Meanwhile, a total of 53 differential compounds were screened out, among which, amino acids, catechins, flavonoid glycosides, lipids, purine nucleosides, organic acids and other compounds were the key components for the formation of Xinyang Maojian tea flavor and quality. In particular, the relative contents of some acylated flavonoid glycosides, lysophosphatidyls and purine nucleosides were significantly elevated after fixing. Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathway enrichment analysis showed that the differential compounds were significantly enriched in the pathways of purine metabolism, glycerophospholipid metabolism, phenylalanine metabolism, aminoacyl-tRNA biosynthesis, phenylalanine, tyrosine, and tryptophan biosynthesis, and glycine, serine and threonine metabolism (P < 0.05). This study further explored the main non-volatile metabolites affecting the flavor and quality of Xinyang Maojian tea, and provided the basis and reference for revealing the flavor and quality formation mechanism of Xinyang Maojian tea.

Key words: Non-targeted metabolomics, Xinyang Maojian tea, Tea processing, Non-volatile metabolites