Salt-mediated flavor dynamics in marinated crayfish (Procambarus clarkii): Multi-omics evidence for the dual role of NaCl in regulating saltiness and flavor formation

Balancing flavor and health in Marinated Crayfish (MC) requires precise salt addition. This study deciphered how salt (0–4 %) shapes flavor via integrated metabolic and volatile profiling. Multivariate statistics identified 15 key non-volatile and 11 pivotal volatile metabolites. Mechanistically, salt modulates flavor through salting-out and osmotic effects, alongside lipid oxidation changes. At lower levels (0–1 %), salt retained endogenous free amino acids and nucleotides, though the product tasted bland due to insufficient saltiness. Conversely, higher salt (3–4 %) enhanced saltiness but reduced endogenous compounds and impeded key exogenous volatiles, including β-pinene, limonene, sabinene, 4-carene, copanene and p-cymene. Critically, increased salt shifted lipid oxidation pathways, elevating 2-decanone, p-menth-1-en-9-al, and limonene oxide, while suppressing decanal and 1-octen-3-ol. Collectively, NaCl imparts saltiness but depletes characteristic flavor compounds. Therefore, 2 % salt is identified as the optimal target for MC, balancing saltiness with flavor complexity and providing a practical guideline for future optimization.