High-throughput lipidomic profiling of high-density lipoprotein from egg yolk (EYHDL): comparison based on UPLC-MS/MS and GC–MS

High-density lipoproteins from egg yolk (EYHDL), also called lipovitellenin, is the second largest constituent of egg yolk (EY), and possesses important functional properties in lipid metabolism for its high content of phospholipids. To better understand its lipid profile, a lipidomic analysis based on ultrahigh-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) and gas chromatography and mass spectrometry (GC–MS) was conducted. Compared with EY, the lower level of triglyceride (TG), higher level of phosphatidylcholine (PC), phosphatidylinositol (PI), and diglyceride (DG) were found in EYHDL (p < 0.01). The orthogonal partial least squares-discriminant analysis (OPLS-DA) revealed that the lipid profile of EYHDL was clearly discriminated from EY. Volcano plots combined with S-plots showed that the differential lipids in EYHDL were 22 significantly downregulated TG with long-chain fatty acids in ES+ , and 30 markedly upregulated lipids including PC, phosphatidylethanolamine (PE), and PI with long-chain fatty acids in ES− (p < 0.01). GC–MS analysis showed higher level of C18:1 and C22:6, and lower level of C16:0 in EYHDL than EY. In summary, EYHDL could serve as a favorable lipid source for human diets for its higher PC, PI, and lower TG.