Multi-omics approach deciphering the lipid oxidation driving quality deterioration in air-dried hairtail (Trichiurus lepturus) during refrigerated storage

This study comprehensively investigated the changes in physicochemical properties, volatile flavor characteristics, microbial diversity, and lipid profiles of air-dried hairtail ( Trichiurus lepturus ) during 6 days of storage at 4 °C, elucidating the mechanisms of quality deterioration driven by lipid oxidation. Basic physicochemical indicators, volatile metabolomics, high-throughput microbial sequencing, non-targeted lipid metabolomics, and targeted medium-long chain lipid metabolomics were employed to evaluate the associated effects. As storage time increased, acid value (AV) and total volatile basic nitrogen (TVBN) of the air-dried hairtail muscle continuously increased, while the hydroxyl radical scavenging capacity (HRSC) and superoxide radical scavenging capacity (SRSC) continuously decreased. Two dominant bacterial phyla ( Proteobacteria and Firmicutes ) and two bacterial genera ( Photobacterium and Psychrobacter ) were identified as key microorganisms in the quality deterioration of air-dried hairtail during refrigerated storage. Additionally, 15 key flavor difference markers, 30 key lipid difference markers, and 42 medium-long chain fatty acids were identified as key metabolites. Correlation analysis further indicated that Firmicutes and Photobacterium , arachidonylethanolamide (AEA, 15:1), triglyceride (TG, 4:0/18:1/20:4; 4:0/18:1/18:1), and 42 medium-long chain fatty acids were the key contributors to the formation of key flavors (ethylenediamine and dodecanal). This study provides a comprehensive understanding of the quality changes in air-dried hairtail during storage and is of great significance for precisely regulating the quality of air-dried hairtail and enhancing the industrial benefits of traditional dried aquatic products.