Reveal the differences in flavor of five varieties of black teas via sensory evaluation, UPLC, and GC × GC-QTOFMS approaches

Commercial black teas vary widely, yet the formation mechanisms of their distinct flavors remain unclear. Here, five different varieties of black teas with medium commercial quality were collected and characterized by integrating flavoromics and chemometric approaches. Soluble sugar, gallocatechin gallate, free amino acids, caffeine, and flavonoids were identified as characteristic taste components. Among 165 identified volatiles, with 51 compounds as key odorants contributing to the diverse aromas of black teas. The 21, 22, 37, 25 and 22 aroma-active compounds were smelled in ZY, QM, ZS, FQ, and HP, respectively. The VIP, ROAV and GC-O results indicated that linalool, phenylethyl alcohol, linalool oxide I and (E)-furan linalool oxide were important aroma-active compounds present in all five black teas. Heptanal characterized FQ, while α-cubebene and trans-calamenene characterized HP and ZS. The results provide a basis for the study of flavor property and quality control of black tea.