The effect of adding human Milk phospholipid analogs on the digestive properties of infant formula

Phospholipids are important structural components of the milk fat globule membrane (MFGM) and contribute to fat globule integrity and lipid digestion. In this study, human milk phospholipid analogs (HMPAs) were prepared by blending yak ghee sphingomyelin-rich phospholipids (SMPL), soybean lecithin (SL), egg yolk lecithin (EYL), and sunflower lecithin (SSL). The optimized HMPAs blend contained 39% SL, 11% EYL, 18% SSL, and 32% SMPL, giving the highest calculated similarity score (88.315) to the selected human milk phospholipid and fatty acid targets. HMPAs were then combined with commercial MFGM material at different mass ratios to construct composite interfacial layers around blended oils. Among the tested systems, the 1:1 HMPAs-to-MFGM ratio showed the most balanced emulsion behavior, with a concentrated particle-size distribution, the lowest stability constant, and an interfacial protein pattern closest to human milk among the prepared emulsions. When this ratio was used to prepare simulated infant formula (SIF), the SIF showed free fatty acid release and post-digestion phospholipid profiles closer to human milk than the two commercial formula controls under the applied in vitro infant digestion model. Under the in vitro model conditions of this study, these findings suggest that combining HMPAs with MFGM material can help regulate the phospholipid composition and interfacial structure of infant formula emulsions.