Investigation of the changes in the lipid profiles in hairtail (Trichiurus haumela) muscle during frozen storage using chemical and LC/MS-based lipidomics analysis

•Alterations in lipid profiles were investigated in hairtail during frozen storage.•Cold stress exacerbated PV and TBARS values in hairtail muscle.•220 DALs were identified in the hairtail muscle due to frozen storage.•Several PEs, PCs, and DGs are vulnerable to oxidation due to high unsaturation.•Modification, cleavage, and/or decomposition of lipids likely occurred in hairtail muscle. Chemical and LC/MS-based lipidomics strategies were performed to explore the alterations of lipid profiles in hairtail (Trichiurus haumela) muscle during 120 days of frozen storage. Chemical results indicated that the PV and TBARS values in hairtail muscle significantly increased during 120 days of frozen storage. Lipidomics results detected 1223 lipids in hairtail muscle assigned to 26 lipid categories, including 261 triglycerides (TGs), 251 phosphatidylcholines (PCs), 153 phosphatidylethanolamines (PEs), and 66 diglycerides (DGs). Totally, 153 and 67 differentially abundant lipids (DALs) accumulated at high and low levels, respectively, were detected in frozen hairtail (FSH) compared to in fresh (FH) samples. Among these, PEs, PCs, and TGs/DGs as predominant lipid components were vulnerable to oxidation/hydrolysis mainly due to their unsaturated properties. The apparent alterations between FSH and FH samples may result from lipid side-chain modifications, backbone cleavage, and/or decomposition of lipids during long-term storage. This study provides novel insight into the molecular mechanisms of lipid alternations in hairtail muscle during frozen storage.