Exploration of the effects of geographical regions on the volatile and non-volatile metabolites of black tea utilizing multiple intelligent sensory technologies and untargeted metabolomics analysis

Geographical regions profoundly influence the flavor characteristics of Congou black tea (CBT). In this study, 35 CBT samples from 7 geographical regions were comprehensively characterized by integrated multiple intelligent sensory technologies and untargeted metabolomics analysis. A satisfactory discrimination was achieved through the fusion of multiple intelligent sensory technologies (R²Y = 0.918, Q² = 0.859). A total of 104 non-volatile and 169 volatile metabolites were identified by UHPLC-HRMS and GC-MS, respectively. Of these, 45 critical differential non-volatile metabolites and 76 pivotal differential volatile metabolites were pinpointed based on variable importance in projection >1 and p < 0.05. Moreover, 52 key odorants with OAV ≥ 1 were identified, with hexanal, phenylacetaldehyde, linalool, β-cyclocitral, methyl salicylate, geraniol, α-ethylidene phenylacetaldehyde, and trans-β-ionone being recognized as the common odorants across 7 geographical regions. The results provide theoretical support for a comprehensive understanding of the effect of geographical regions on the flavor of black tea.