Comprehensive investigation on non-volatile and volatile metabolites in four types of green teas obtained from the same tea cultivar of Longjing 43 (Camellia sinensis var. sinensis) using the widely targeted metabolomics

Abstract

In this study, we produced roasted, baked, steamed, and sun-dried green tea products using the same batch of fresh tea leaves (FTL) of Longjing 43 (Camellia sinensis var. sinensis), and explored processing effects on the metabolic profiles of four types of green teas (FGTs) using the widely targeted metabolomics. Results showed that 146 differential metabolites including flavonoids, amino acids, lipids, and phenolic acids were screened among 1034 non-volatiles. In addition, nineteen differential metabolites were screened among 79 volatiles. Most of non-volatiles and volatiles metabolites changed notably in different manufacturing processes, whereas there were no significant differences (p＞0.05) in the levels of total catechins between FGTs and FTL. The transformation of metabolites was the dominant trend during green tea processing. The results contribute to a better understanding of how the manufacturing process influences green tea quality, and provide useful information for the enrichment of tea biochemistry theory.

Keywords: Differential metabolite; Epigallocatechin gallate (PubChem, CID65064); Geraniol (PubChem, CID637566); Green tea; Kaempferol (PubChem, CID5280863); Linalool (PubChem, CID6549); Methyl salicylate (PubChem, CID4133); Non-volatile metabolite; Phenylethyl alcohol (PubChem, CID6054); Process technology; Quercetin (PubChem, CID5280343); Theanine (PubChem, CID439378); Volatiles; Widely targeted metabolomics; l-Phenylalanine (PubChem, CID6140); α-Linolenic acid (PubChem, CID860).