Lipidomics Analysis of Different Marine Fish Oils Using Untargeted Liquid Chromatography–Orbitrap High-Resolution Mass Spectrometry and Chemometrics

Marine fish oils (MFOs) have been known for their nutritional compounds, which benefit human health. MFOs contain various lipids which play an essential role in human nutrition. The objective of this research was to apply untargeted lipidomics analysis using liquid chromatography–high-resolution mass spectrometry (LC–HRMS) for the comprehensive identification of lipid compositions extracted from five different marine fishes, namely red snapper ( Lutjanus campechanus (A1)) , giant grouper ( Epinephelus lanceolatus (A2)), baronang crochet ( Siganus canaliculatus (B2)), white snapper ( Lates calcarifer (C3)), skipjack tuna ( Katsuwonus pelamis (D2)). More than 1000 lipid compounds from both positive and negative ionization modes could be detected in each MFO using LC–HRMS untargeted lipidomics analysis. Most lipids were dominated by triglycerides (TG) and diglycerides (DG) classes. Principal component analysis (PCA) and partial least square-discriminant analysis (PLS-DA) could classify MFO samples in positive and negative ionization modes. Based on variable importance for projections (VIP) value, 15 differentiating lipid compounds were found to have an essential role as potential biomarkers in positive ionization mode. In contrast, ten differentiating lipid compounds were found in negative ionization mode. It can be concluded that untargeted lipidomics using LC–HRMS could be used as a powerful analytical technique for comprehensively identifying lipid compositions in MFO samples. It can be further used to identify the lipid compositions of other fish oil samples.