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

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 nonvolatiles 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.

Automated summary

This study investigated the impact of different processing methods on the metabolic profiles of green tea. Using the same batch of fresh tea leaves, various types of green teas were produced and analyzed. The results showed significant changes in non-volatile and volatile metabolites during different manufacturing processes, while the levels of total catechins remained consistent. This research contributes to a better understanding of how the manufacturing process affects the quality of green tea.