Comparative characterization of triacylglycerols in human milk, infant formula, structured lipids, and plant oils using UPSFC-Q-TOF-MS

Triacylglycerol (TAG) components in human milk, infant formulas with different fat sources, and plant oils (palm oil, flaxseed oil, sunflower oil, corn oil, soybean oil, coconut oil, low erucic acid rapeseed oil, and high oleic acid rapeseed oil) were analyzed and compared using ultraperformance supercritical fluid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPSFC-Q-TOF-MS). Distinct TAG profiles were identified by lipidomics, principal component analysis (PCA), and heatmap visualization. Human milk was characterized by a high abundance of medium- and long-chain triacylglycerols (MLCTs), saturated-unsaturated-unsaturated (SUU)-type TAGs ( sn -2 palmitic acid). In contrast, plant oils lacked MLCTs and SUU-type TAGs, containing mainly TAGs esterified long-chain polyunsaturated fatty acid. Breast milk contains about 27% MLCT, about 50% SUU-type triacylglycerols (which contain about 34% UPU-type triacylglycerols), which is significantly different from plant oils, structured fats and infant formulas. These findings provide a clear basis for optimizing the fat blend in infant formula to better mimic the unique TAG profile of human milk, thereby improving energy delivery and nutrient absorption for infants.