A comprehensive study of lipid profiles of round scad (Decapterus maruadsi) based on lipidomic with UPLC-Q-Exactive Orbitrap-MS

Round scad (Decapterus maruadsi) is rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). However, there is no comprehensive information covering its lipidomic profile. In this study, lipid profiles including fatty acid composition, distribution and detailed structure information were explored using gas chromatography-flame ionization detector (GC-FID) and ultra-high-performance liquid chromatography coupled with hybrid quadrupole-orbitrap mass spectrometry (UPLC-Q-Exactive Orbitrap-MS). The results showed that triacylglycerol (TG) was the dominant class, and the EPA and DHA were concentrated as glycerophospholipid (GP). The saturated fatty acids and monounsaturated fatty acids were mainly esterified in positions 1 and 3 of TG and sn-1-position of GP, while the polyunsaturated fatty acids (PUFA) were mainly esterified in sn-2-position of TG and GP. A total of 1282 species from six classes (21 subclasses) including glycerolipids (GL), sphingolipids (SP), GP, fatty acyls (FA), saccharolipids (SL) and prenol lipids (PR) were identified. Several molecular species were characterized with PUFA, especially EPA and DHA in GP. Considering the superior fatty acids composition and distribution of round scad, it is deserved for further exploitation of its marine lipid source on account of the healthy and nutritional functions.