Characterization of the key metabolites in the raw Pu-erh tea under different storage environments

The storage of raw Pu-erh tea (RPT) is essential for its quality development, yet how environmental factors such as temperature and humidity collectively influence flavor formation during long-term natural storage remains incompletely understood. In this study, a molecular sensory analytical approach combining HPLC and GC × GC-O-Q-TOFMS was applied to characterize RPT samples stored for 13 years under contrasting environments. Results showed that wet-hot environments were associated with increased concentrations of DL-catechin and gallic acid, contributing to a mellower taste, whereas relatively dry-cold environments favored the retention of umami and astringency. In terms of aroma, a total of 339 compounds were identified, of which 26 aroma-active compounds were selected as key discriminators. Correlation analysis indicated that the contents of aging-related compounds such as 1,2,3-trimethoxybenzene and α-terpineol were positively associated with wet-hot environments, while β-ionone and β-cyclocitral exhibited opposite trends. Overall, this study provides systematic demonstrations that storage environment actively directs the long-term flavor transformation of RPT through coordinated modulation of key volatile and non-volatile metabolites, offering new insights into environment-driven quality formation.