This review systematically explores the spatiotemporal microbial succession and flavor evolution during the fermentation of northeast Chinese soybean paste (dajiang), with a focus on the jiangpei (solid-state starter) and jianglao (brine fermentation) stages. By integrating metagenomic, metabolomic, and sensory data, this review synthesizes evidence linking microbial community dynamics-featuring Lactobacillus spp., Zygosaccharomyces rouxii, and Aspergillus oryzae-to the biosynthesis of key flavor compounds. These include umami amino acids (e.g., glutamic acid, 1.5-2.0 g/kg), fruity esters (e.g., ethyl acetate, 124.67 μg/kg), and phenolic antioxidants. Cross-feeding interactions (e.g., yeast utilization of lactic acid for ester synthesis) and environmental stressors (12%-18% NaCl, 25 °C-30 °C) are shown to enhance flavor complexity by modulating metabolic pathways like amino acid degradation and lipid β-oxidation. Unlike prior studies focusing on fragmented fermentation stages, this review systematically addresses the full fermentation continuum, highlighting how aerobic-to-anaerobic transitions drive functional metabolite accumulation. The review concludes by outlining a roadmap to modernize dajiang production through standardized quality control, precision flavor modulation, and traditional process optimization, enabled by culturomics/MAGs, multi-omics integration, and AI-assisted fermentation monitoring and control.
Song et al. (Fri,) studied this question.