UPLC–QTOF/MS-based non-targeted metabolomics coupled with the quality component, QDA, to reveal the taste and metabolite characteristics of six types of Congou black tea

This study revealed the taste and metabolite differences, as well as their associations, in six types of Congou black tea. There were significant differences between the nine taste attributes of the six types of Congou black tea, and their common dominant taste attribute was sweetness. A total of 135 differential metabolites were identified and mapped into 42 metabolic pathways. A weighted gene coexpression network analysis showed that 93 metabolites were significantly related to the taste attributes, and these were mainly involved in regulating the sweetness, astringency, thickness and mellow of the Congou black tea. There were also significant differences in the main quality components, and Xinyang black tea had the lowest content of EGC and the highest total amount of theaflavins. Based on the cluster analysis of metabolite profile and quality components, the six types of Congou black tea were divided into two categories, one was Ninghong, Chuanhong, Xinyang and Huhong Congou black tea, and the other was Dianhong and Yinghong Congou black tea. This study has provided a detailed overview of the taste and metabolite characteristics of six types of Congou black tea, which is highly significant for the control of flavor quality and directional regulation of black tea.