Effects of diets supplemented with n–3 or n–6 PUFA on pig muscle lipid metabolites measured by non-targeted LC–MS lipidomic profiling

Abstract UPLC-ESI-QTOF-MS was applied for investigation of diet effects on lipid metabolites in muscle of Landrace pigs that were fed n –3 or n –6 PUFA supplemented diets. In total, over 1200 lipid metabolites were detected in pig muscle, and 187 lipids were significantly different between the diet groups. The fold-change (FC) values were much higher (up to 29) for lipid metabolites in the pig muscle of n –3 PUFA compared with those in the n –6 PUFA group. The n –3/ n– 6 PUFA diet intervention mainly appeared to affect fatty acids within the lipid metabolites and did not appear to alter the lipid class distribution. The results of the LC–MS profiling were reflected in GC-FID-based single fatty acid profiling of the muscle phospholipids and triglycerides. The findings show that there is a discrepancy between the high number of dietary-based different lipid metabolites and the low dietary effects on the expression of lipogenic proteins in pig muscle. In conclusion, pig muscle lipid metabolism after being fed different PUFA diets can be elucidated by using a combination of lipidomics studies and functional genomic approaches.