Modulating the flavor quality of black tea by exogenous enzymes: Insights from intelligent sensory technologies and metabolomics.

This study employed intelligent sensory technologies combining with metabolomics to elucidate the effects of four exogenous enzymes on black tea flavor quality. Sensory assessment demonstrated that α-galactosidase treatment yielded the highest overall quality score with a notable emphasis on aroma, whereas cellulase optimally enhanced the taste profile. Utilizing GC-MS/MS and UHPLC-Q-Exactive/MS platforms, 72 volatile and 131 non-volatile metabolites were characterized. In aroma development, glycosidase treatments were most effective in elevating glycosidically bound volatile (GDV) levels. α-Galactosidase, in particular, exhibited the greatest efficacy in modulating the GDV profile, imparting distinct sweet and floral notes. Regarding non-volatile metabolites, cellulase treatment stimulated the accumulation of key differential metabolites, such as amino acids, nucleotides, and carbohydrates, which collectively underpin the development of a brisk, mellow, and well-rounded taste profile. These findings unravel the flavor modulation at the metabolite level by exogenous enzymes, offering a theoretical basis for targeted quality enhancement in tea manufacturing.