Effects of cold treatments on lipidomics profiles of large yellow croaker (Larimichthys crocea) fillets by UPLC-Q-Exactive Orbitrap MS analysis

Cold treatment offers an effective avenue to preserve large yellow croaker fillets. However, the lipid distribution of fillets is unclear after cold treatments. This study aimed to identify differences of lipids among the fresh (RAW) and two cold treatments (− 1 ℃ and − 3 ℃) of large yellow croaker fillets using a lipidomics approach. A total of 2317 lipid species in RAW and two cold treatments were recognized and assigned to 13 sub-classes of lipids by using ultra-high-performance liquid chromatography-Q-exactive orbitrap mass spectrometry (UPLC-Q-Exactive Orbitrap MS) and lipidsearch software approach. Furthermore, there are 54 significantly different lipids were selected as potential lipid candidates of lipid oxidation of fillets by using correlation analysis between all individual lipids variables and freshness indicators (color, pH, thiobarbituric acid reactive substances, and total volatile bases nitrogen). All these potential candidates had involved 6 metabolic pathways that found the significant metabolic process on lipid oxidation after cold treatments. The autophagy-animal and glycerophospholipid metabolism were found to be two important pathways to analyze the lipids change, and were used to find the significant potential candidates of lipid oxidation on cold treatment. This work could provide a novel insight on the lipid changes analysis of large yellow croaker fillets after cold treatments.