Study on the influence of microorganisms on the flavor of black tea

In this study, microorganisms isolated from black tea (BT) processing samples were added to BT fermentation, and the volatile profile and chemical characteristics of BT fermented by adding single tea-derived microbe were investigated. Briefly, a total of 14 yeast and 33 bacteria were isolated, among which five were selected for BT fermentation. Adding tea-derived microorganisms during fermentation increased the contents of water extract, caffeine, and theabrownins while reduced soluble sugars, gallic acid, and ester catechins content in BT, with better quality observed in Hanseniaspora uvarum RL-B and Bacillus amyloliquefaciens N1 fermented samples. Additionally, tea-derived microbial fermentation altered the composition of volatile compounds, predominantly alcohols, esters, terpenoids, and hydrocarbons. It decreased volatiles content that presenting sweet and floral flavor whereas enhanced those exhibiting nutty and fruity-like green fragrance by modulating the monoterpenoid biosynthesis pathway. These findings provide new insights into the mechanisms by which microorganisms influence the quality formation of BT.