Effect of phospholipid matrix on emulsion stability, microstructure, proteolysis, and in vitro digestibility in model infant formula emulsion

The effects of adding different phospholipid (PL) matrices [milk sphingomyelin (SM) vs soy phosphatidylcholine (PC)] on emulsion stability, microstructure, and in vitro simulated lipid digestion were examined using a Model Infant Formula Emulsion (MIFE). The emulsion stability of MIFE increased significantly with PL addition (0.1 and 0.2 %). Compared to sole MIFE or MIFE + PC, the incorporation of SM resulted in increased emulsion stability (p < 0.05) and a greater amount of free fatty acid release (p < 0.05) during in vitro simulated digestion. This was mainly due to the reduction of intensive droplet aggregation, thus providing a large surface area and improved digestibility. This is further experimentally supported by the evolution of particle size distribution, zeta-potential, and microstructure analysis using confocal laser scanning microscopy. The incorporation of SM in the emulsion formation significantly delayed digestion of beta-lactoglobulin during in vitro digestion. Lipid di-gestibility in MIFE was altered depending on the type of PL matrix, and SM displayed a superior effect to PC. Thus, the creation of a novel emulsion interface by the appropriate selection of emulsifiers can be used to improve lipid digestion in infants and obtain desirable nutritional consequences.

Automated summary

The effects of adding different phospholipid (PL) matrices on emulsion stability, microstructure, and in vitro simulated lipid digestion were studied. The addition of milk sphingomyelin (SM) significantly increased emulsion stability and free fatty acid release during digestion compared to soy phosphatidylcholine (PC). This was attributed to reduced droplet aggregation and improved digestibility. The incorporation of SM also delayed the digestion of beta-lactoglobulin. Thus, the selection of appropriate emulsifiers can enhance lipid digestion in infants and have nutritional benefits.