Comparative Lipid Profile Analysis of Four Fish Species by Ultraperformance Liquid Chromatography Coupled with Quadrupole Time-of-Flight Mass Spectrometry

A high-throughput lipid analysis method was established to comprehensively investigate the lipid profiles of three marine (Scomberomorus niphonius, Scophthalmus maximus, and Oncorhynchus keta) and one freshwater (Ctenopharyngodon idellus) fish species using ultraperformance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. Over 700 molecular species from 12 major lipid subclasses were identified. Glycerolipids (73.7-85.6%) and phospholipids (PLs, 13.7-25.6%) were dominant components in total lipids. Polyunsaturated fatty acid PLs, such as phosphatidylethanolamine (PE, 16:0-22:6), PE (18:1-22:6), and phosphatidylcholine (16:0-22:6), were the major molecular species in PLs. The lipid composition of three marine fish (mainly C22:5) was significantly different from that in C. idellus (mainly C20:4 and C20:5). A unique long-chain base of sphingolipids was found in fish (mainly d19:3). These bioactive lipids were proposed to be potential biomarkers for distinguishing different fish species and evaluating nutritional values.