Lipid pro-oxidative reactions mediated by heat, light and microwave and the structural characteristics of their products: Revealed via multi-omics approaches

Heat, light, and microwave treatments differentially modulate food flavor profiles through lipid oxidation, but the mechanistic distinctions remain unclear. This study monitored and compared lipid molecular species and flavor compounds in salmon oil processed by these methods via multi-omics technology. Thermal treatment yielded the highest concentrations of alkanes, alkenals, enols, and aldehydes (50.09 % of total volatiles), predominantly C₅–C₁₀ compounds. Light treatment generated alkenes, enols, alcohols, and alkanes (74.85 % of total volatiles), primarily C₄–C₅ and C₈ compounds. Microwave processing enriched enols, benzenes, alkenals, and alkenes (72.28 % of total volatiles), predominantly C₄–C₁₀ compounds. Volatiles were primarily derived from polyunsaturated triglycerides, with even‑carbon fatty acids undergoing chain shortening to odd‑carbon species during reaction. Microwave-induced lipid oxidation mechanism was linked to both thermal and photo oxidation, attributing to its electromagnetic wave properties and thermal effects. These findings provide a theoretical basis for precise flavor modulation through combining several processing methods