Characterization and correlation analysis of microbial, non-volatile and volatile metabolite changes during the multi-step roasted bacon

This study systematically investigated the dynamic changes in microbial characteristics, quality attributes, and flavor metabolites during the roasting process of Multi-step roasted bacon (MRBs), under optimized curing conditions. The results indicated that roasting drove the succession of microbial communities; Candida and Staphylococcus were the dominant genera before roasting, while Aspergillus and Staphylococcus became predominant after roasting. Quantitative profiling of 42 key volatile flavor compounds revealed that the third roasting step (TR) produced meat with the highest concentration of flavor compounds. Moreover, integrative analysis of the metabolome and microbiome uncovered strong correlations between specific metabolites, including Guaiacol, ethyl caprate, L-leucine, and 4-pyridoxic acid, with Staphylococcus , Aspergillus , and Candida ( P < 0.05). Proteases secreted by these microorganisms played a pivotal role in enhancing flavor development, contributing to the overall sensory quality of the cured meat. These findings provide valuable insights for optimizing the production processes of cured meat products. • Optimized the processing flow of cured meat. • Staphylococcus and Aspergillus are the main genera of microorganisms in MRBs. • Revealed the dynamic changes of metabolites during the processing of MRBs. • Results show that multi-step roasting can increase the content of volatile compounds. • Discussed the correlation between microorganisms and flavor substances/metabolites.