Comprehensive lipidomics and flavoromics reveals the accelerated oxidation mechanism of fish oil from silver carp (Hypophthalmichthys molitrix) viscera during heating

This study employed gas chromatography-mass spectrometry (GC-MS) and lipidomic approaches to analyze volatile organic compounds (VOCs) and lipid dynamics in silver carp visceral fish oil during accelerated oxidation at 60 degrees C. The lipidomic profiling revealed 1362 distinct lipid molecules, encompassing 92 fatty acids. Triglycerides (TGs) underwent degradation in the early oxidation phase (0-6 days), whereas glycerophospholipid breakdown dominated the later stages (9-20 days). Among 44 detected VOCs, six compounds including nonanal, (E,E)-2,4-heptadienal, (E)-2-nonenal, (E)-2-decenal, 1-octen-3-ol, and eugenol were identified as critical flavor contributors based on odor activity values (OAV) exceeding 1.0. Notably, 1-octen-3-ol and (E)-2-decenal were hypothesized to derive from phosphatidylethanolamine (PE), TG, and ceramide (Cer) degradation. Key lipid classes linked to flavor deterioration included PE with odd-chain and unsaturated fatty acids (UFAs), TG rich in polyunsaturated fatty acids (PUFAs), and Cer containing monounsaturated fatty acids (MUFAs). These insights enhance mechanistic understanding of oxidative flavor changes in fish oils.