Substrate composition shapes microbial communities and aroma profiles of co-fermented sour shrimp paste
摘要
The co-fermentation of animal and plant materials is a traditional Asian food practice exemplified by sour shrimp paste. However, how substrate composition shapes the aroma profile remains unclear. This study elucidates the effect of substrate composition on aroma formation in sour shrimp paste through aroma profiling and metagenomic analysis. The results demonstrated that plant materials lowered the pH from 7.8 (shrimp paste only) to 4.7-5.9. Higher shrimp content increased sulfur‑ and nitrogen‑containing compounds, while cereal and chili enhanced esters, alcohols, acids, aldehydes, terpenoids, and norisoprenoids. The co-fermentation of shrimp paste and plant materials produced more branched-chain volatiles, 2,3-dimethylbutanol, 4-vinylguaiacol, and methyl trisulfide, indicating active microbial metabolite exchange between animal- and plant-based matrices. The cereal-shrimp co-fermentation’s microbial community was similar to that of shrimp paste and was dominated by lactic acid bacteria and halophiles (e.g., Tetragenococcus, Staphylococcus). The addition of chili enriched Pichia, Levilactobacillus, Lactiplantibacillus, and molds (e.g., Aspergillus). Among them, L. brevis and L. plantarum were major aroma drivers, correlating with key aroma compounds. This study provides insights into aroma formation in co‑fermented foods and substrate regulation strategies.