Integrated untargeted and targeted metabolomics and microbiome profiling reveal the effects of storage duration on the flavor quality of Rizhao Jinhua white tea

The post-fermented tea develops enhanced quality attributes with prolonged storage. In this study, we explored the dynamic changes in sensory characteristics, untargeted and targeted metabolomics, and microbial communities of Rizhao Jinhua white tea (WFB) across different storage years. Storage process reduced bitterness and astringency, while improving overall mellowness. Levels of total polyphenols, amino acids, theaflavins, and thearubigins declined significantly, whereas theabrownin reached its peak at year 5. Among 118 identified differential metabolites, flavonoids exhibited the most pronounced variations. Further targeted quantification of flavonoids revealed catechin, epicatechin, epigallocatechin, quercitrin, and isorhamnetin as key flavor determinants. This was related to glycosylation, hydrogenation, hydroxylation, and hydrolysis reactions occurring during storage. Dominant microbial genera such as Aspergillus and Pseudomonas continuously promoted flavonoids transformations during storage. The outcomes of this research support better approaches to flavor quality optimization in stored Jinhua white tea.