Unraveling volatile and microbial dynamics of Pukeng tea with different storage times using metabolomics, chemometrics, and microbiome analysis.

Pukeng tea (PKT), a traditional Chinese dark tea, has been consumed for centuries, yet its volatile and microbial dynamics remain unclear. This study integrated metabolomics, chemometrics, and microbiome analysis to explore PKTs with 3-20 years of storage. HS-SPME-GC-MS identified 189 volatiles, mainly alcohols, aldehydes, and ketones. PCA and PLS-DA revealed distinct metabolite patterns, with 46 differential volatiles, such as 1-butanol and 1-penten-3-ol, characterized as potential discriminants among PKT samples. Microbiota analysis showed 11 dominant bacterial genera, shifting from Firmicutes in early storage to Actinobacteriota in later stages, while Aspergillus dominated fungal communities. Correlation analysis revealed significant associations between dominant microbes such as Staphylococcus and Saccharopolyspora and aroma-active volatiles, suggesting microbial contributions to PKT's evolving flavor. This study provides the first integrated characterization of volatile and microbial diversity in PKT, offering insights into quality control, product authentication, and functional microbe discovery for the sustainable development of traditional dark teas.