Comprehensive lipid profiles of sea cage aquaculture cobia (Rachycentron canadum) based on lipidomics

Abstract

Cobia (Rachycentron canadum) is a significant fish species for mariculture with high nutritional value. This research aims to comprehensively investigate the lipid profiles of cobia tissues, including fatty acid profiles, characteristics of phospholipids (PL) and triacylglycerols (TAG), and lipid molecular species. The results showed that cobia contained high levels of total lipids (2.89 −32.09 % of wet weight), docosahexaenoic acid (DHA, 10.83 −14.69 % of total fatty acids) and eicosapentaenoic acid (EPA, 3.54 −9.68 %). Compared with TAG, higher levels of polyunsaturated fatty acids, DHA/EPA in particular, were concentrated in PL. Interestingly, DHA was predominantly distributed in the sn-1 position of PL and the sn-2 position of TAG, whereas EPA was predominantly distributed in the external positions of PL and TAG. Additionally, at least 693 molecular species from 23 subclasses were identified by ultrahigh-performance liquid chromatography-quadrupole exactive-mass spectrometry (UPLC-Q-Exactive-MS). Glycerophospholipids (63.19 −66.61 %) and glycerolipids (19.17 −22.21%) were the major lipid classes in cobia tissues, and the majority of them contained DHA and EPA. Hence, this comprehensive analysis will help to evaluate the lipid nutritional values and facilitate exploitation in cobia consumption and processing.