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Wei Xinlin’s Team Unveiled Metabolomic Changes in Qingzhuan Tea Processing

April 20, 2020      Author: Cheng Lizeng

Recently, Wei Xinlin's research group from School of Agriculture and Biology, SJTU, combined LC-MS-based metabolomics analyses with multivariate analysis to characterize the chemical composition of Qingzhuan tea (QZT) and investigate the effect of QZT processing on its metabolic profile and sensory quality. Related research findings were published in the Journal of Agricultural and Food Chemistry (IF:3.57) titled "LC-MS-based metabolomics reveals the distinct changes of metabolic profile and sensory quality during Qingzhuan tea processing". The first author is doctoral student Cheng Li and the corresponding author is researcher Wei Xinlin .

This research has been supported by the China National Key R&D Program during the 13th Five-year Plan Period under the project named "Application demonstration of tea product quality and safety control technology and health function evaluation" (Grant No. 2018YFC1604400). Researcher Wei Xinlin is the Chief Scientist of this program.

Abstract:

Qingzhuan tea (QZT) is a unique type of dark tea exclusively produced in Hubei Province of China. In the current study, liquid chromatography-mass spectrometry (LC-MS) coupled with multivariate analysis was applied to characterize the chemical composition of QZT and investigate the effect of QZT processing on its metabolic profile and sensory quality. The contents of polyphenols and flavonoids decreased significantly whilst the polysaccharides content remained stable, while the theabrownin content inversely increased during QZT processing. LC-MS-based metabolomics analyses revealed that tea sample after microbial fermentation (MFT) was dramatically different from the sample before microbial fermentation (UFT), while MFT was very similar to QZT. A total of 102 compounds was identified as critical metabolites responsible for metabolic changes caused by QZT processing, with the contents of catechins and flavonoids significantly decreased, and some novel phenolic acids and catechin derivatives formed. The sensory quality of QZT was mainly formed during microbial fermentation, which greatly reduced the astringency and bitterness of raw tea leaves, and produced its characteristic woody and stale aroma as well as mellow taste. These results suggested that microbial fermentation is the critical process in changing the metabolic profile of raw tea leaves and forming sensory quality of QZT.

 

Link: https://pubs.acs.org/doi/10.1021/acs.jafc.0c00581

 

Translated  by Han Yueyue     Reviewed by Wang Bingyu