Correlation Analysis between Microbial Diversity and Flavor Compounds in Sichuan Fermented Sausage

To investigate the correlation between microbial diversity and flavor compounds in Sichuan-style fermented sausages, sausages at different fermentation times were studied using high-throughput sequencing technology in conjunction with electronic tongue, electronic nose, and gas chromatography-ion mobility spectrometry (GC-IMS). The changes in dominant microbial communities and flavor compounds during sausage fermentation were analyzed, and the correlation between microbial diversity and volatile flavor compounds was assessed using Pearson correlation analysis. Results showed that with prolonged sausage fermentation time, the number and abundance of microbes increased, with a total of 12 genera detected, dominated by Lactobacillus and Weissella. In terms of non-volatile compounds, the content of free amino acids, nucleotides, and peptides with bitter and umami tastes gradually increased. Regarding volatile flavor compounds, 52 substances were detected. The concentrations of alcohols, terpenes, and thiazoles decreased gradually, while esters, pyrazines, and aldehydes increased. GC-IMS results further revealed that the characteristic flavor compounds in the early and middle stages of fermentation were similar, mainly composed of limonene, β-myrcene (M), ethanol, β-caryophyllene, and 1,1-diethoxyethane (M). The content of pungent flavor compounds significantly decreased at 35 d of fermentation. The types and concentrations of esters, aldehydes, and pyrazines in the stable fermentation period tended to stabilize. Pearson correlation analysis indicated that five dominant genera including Lactobacillus, Acinetobacter, Pediococcus, Pseudomonas, and Chryseobacterium were positively correlated with 37 volatile flavor compounds. Specifically, Lactobacillus was positively correlated with aldehydes, alcohols, and esters (r>0.6), while Weissella, a subdominant genus, was negatively correlated with alcohols and esters (r<−0.4). These findings suggest a close relationship between dominant microbial communities and the synthesis of sausage flavor compounds, providing a scientific basis and theoretical foundation for the development of efficient and environmentally friendly fermentation agents to regulate the flavor quality of Sichuan-style fermented sausages.