Metabolomics Analysis of Changes in Metabolites During the Fermentation Process of Congou Black Tea

Baojing Huangjincha was used as raw material and processed according to congou black tea technology, used metabolomics-based liquid-mass spectrometry (LC-MS/MS) to detect tea samples during the fermentation process, and analyzed the dynamic changes of metabolites during the fermentation process of congou black tea. The results showed that during the fermentation process, the metabolites in tea showed regular dynamic changes. A total of 493 different metabolites were screened in the study, moreover, the change trend of these different metabolites can be divided into two stages, namely the early stage of fermentation and the later stage of fermentation, taking the 2 h fermentation as the node. In the early stage of fermentation, the metabolites were change significantly, and the material metabolism was active, while the differential metabolites in the later stage of fermentation were significantly less than that in the early stage of fermentation, and the material metabolism was weakened. Analysis of the identified 90 differential metabolites showed that the astringent metabolites were down-regulated during the fermentation of black tea, and the soluble sugars and theaflavins were sweetened and refreshing metabolites were significantly up-regulated. This experiment provides an important reference for exploring the mechanism of substance metabolism regulation in the fermentation process of congou black tea.