Metabolomics reveals the effects of different carbon sources on the quality and flavor profile of low-salt shrimp paste.

To elucidate carbon source effects on low-salt shrimp paste quality and bioactivity, glucose and glutinous rice flour were added pre-fermentation, physicochemical indicators monitored, and flavor and metabolic compound changes analyzed via combined HS-SPME-GC-MS and non-targeted metabolomics. The results showed that the addition of glucose and glutinous rice flour significantly enhanced the quality and flavor of low-salt shrimp paste following 12 days of fermentation. In total, 709 volatile compounds and 2089 non-volatile compounds were putatively annotated. The top 50 volatile compounds in shrimp paste included 7 alcohols, 9 hydrocarbons, and 6 ketones. Sensory analysis showed carbon source-supplemented shrimp paste exhibited enhanced sweetness and fruity aromas. Among the top 20 non-volatile metabolites, organic acids and their derivatives, lipids, and lipoid molecules emerged as primary metabolites. Unique metabolic pathways identified in the carbon-supplemented group-such as cutin, suberine, and wax biosynthesis-promoted flavor development in low-salt shrimp paste.