Effects of storage time on the quality and microbial community of ripe Pu-erh tea

Long-term storage is beneficial to improving the quality of Ripe Pu-erh Tea (RPT). Using RPT with storage time of 0, 5, 10 and 15 years as materials, targeted (HPLC and GC-MS) and non-targeted (UHPLC-Orbitrap-MS and GC × GC-TOFMS) combined volatolomics and metabolomics coupled with electronic sensory evaluation were used to reveal the differences in chemical compositions and microbial community succession of RPT during storage. The results showed that catechin and caffeine were decreased during aging process, the volatile profile also evolved, with a decrease in aldehydes, alcohols, and an increase in hydrocarbons, contributing to the characteristic aged aroma. 1,2,3-trimethoxybenzene and (+)-cedrol were identified as the primary contributors to the "woody" character of RPTs with long storage years. Microbiological analysis identified Aspergillus and Bacillus as dominant genera, playing key roles in metabolite decomposition and synthesis, which influenced the flavor and aroma characteristics of aged RPTs. These findings provide insights into flavor development and quality evolution during long-term storage.