Unveiling key odor-active compounds and bacterial communities in Fu Brick tea from seven Chinese regions: A comprehensive sensomics analysis using GC–MS, GC-O, aroma recombination, omission, and high-throughput sequencing

Fu Brick Tea (FBT) is a unique fermented tea produced in multiple regions of China, whose aroma qualities, key odor-active compounds and bacterial communities are not well characterized. By optimizing HS-SPME methods, utilizing GC–MS, GC-O, sensory analysis, aroma recombination and omission experiments, and bacterial sequencing, we revealed the primary volatiles and bacterial communities in 41 samples from 7 major producing regions. A total of 63 volatiles and 32 odor-active compounds were quantitatively analyzed using GC–MS and GC-O, respectively. Sensory analyses discriminated the quality of the samples. Differential analysis indicated that poor aroma FBTs had either low volatile content or excessive “green” notes. Key odor-active compounds in high-quality aroma FBTs include 1-octen-3-ol, phenylethylalcohol, β -ionone, dihydroactindiolide, and 1,2,3-trimethoxybenzene. Sequencing results identified Bacillus , Pseudomonas , and Streptococcus as dominant genera. Functional prediction analyses suggest that bacteria contribute to the formation of FBT aroma. This study offers new insights into the quality characteristics of FBT.