Volatile aroma profiles and associated microbiota of Yunnan Shiping sour-pulp-fermented stinky tofu.

Yunnan Shiping stinky tofu is a traditional sour-pulp-fermented soybean product with distinctive volatile aroma characteristics. In this study, headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS), relative odor activity value (ROAV) analysis, and 16S rRNA/ITS amplicon sequencing were used to characterize volatile organic compounds (VOCs) and associated microbial communities in samples collected from four local production facilities. A total of 418 VOCs were detected, and ROAV analysis indicated that sulfur-containing compounds, heterocyclic compounds, furanone derivatives, terpenoid-derived odorants, and unsaturated aldehydes contributed substantially to the volatile aroma profile. The bacterial communities were mainly composed of Proteobacteria, Bacteroidota, and Firmicutes, whereas the fungal communities were dominated by Ascomycota and Basidiomycota. Correlation analysis suggested potential associations between selected bacterial or fungal genera and aroma-active compounds; however, these associations should be interpreted as hypothesis-generating rather than causal evidence. These findings provide a descriptive basis for understanding the volatile aroma characteristics and microbial ecology of Yunnan Shiping sour-pulp-fermented stinky tofu and may guide future targeted isolation, safety assessment, and validation of aroma-associated microorganisms.