Metabolomics combined with sensory evaluation discriminate Gougunao tea from different geographic origins

Combined with sensory evaluation, metabolomics, and chemometric analysis, Gougunao tea (GGT) of 3 different origins were discriminated with the variations in quality and chemical composition determined. The findings revealed that a total of 26 non-volatile metabolites were characterized as marker compounds to discriminate GGT samples from 3 different origins. GGT samples from Tanghu exhibited the strongest bitter intensity compared to those from Daijiapu and Quanjiang, which contained higher amounts of catechin, gallocatechin, gallocatechin gallate, galangin, and tea polyphenols, which may contribute to the enhancement of bitterness and astringency. GGT typically exhibits floral, grassy, and fresh aroma. A total of 4 different volatile compounds were chosen to distinguish GGT from various geographical origins. GGT from Daijiapu demonstrated the highest contents of indole, while GGT from Quanjiang showed relatively higher levels of naphthalene and 1,1,5-trimethyl-1,2-dihydronaphthalene, GGT from Tanghu had higher relative contents of β-ocimene. This research presents a novel guidance for recognizing the geographic origins of GGT, which is vital for improving the taste of GGT.