Nontargeted and targeted metabolomics analysis for evaluating the effect of “golden flora” amount on the sensory quality, metabolites, and the alpha-amylase and lipase inhibitory activities of Fu brick tea

To investigate the effects of "golden flora" amount on the sensory quality, metabolites and bioactivities of Fu brick tea (FBT), FBT samples with different "golden flora" amounts were prepared from the same materials by adjusting the water content before pressing. With the increase of "golden flora" in samples, the tea liquor color changed from yellow to orange red and the astringent taste gradually diminished. Targeted analysis demonstrated that (−)-epigallocatechin gallate, (−)-epicatechin gallate, and most amino acids gradually decreased as the increase of "golden flora". Seventy differential metabolites were identified by untargeted analysis. Among them, sixteen compounds including two Fuzhuanins and four EPSFs were positively correlated with "golden flora" amount (P < 0.05). The FBT samples with "golden flora" exhibited significantly higher inhibitory potency on α-amylase and lipase than the samples without "golden flora". Our results provide a theoretical basis of guiding FBT processing based on desired sensory quality and metabolites.