Regulating interfacial structure of fat globules based on milk fat globule membrane with milk phospholipids to improve physicochemical properties and fat digestion of infant formula emulsions

Modulation of a suitable proportion of milk fat globule membrane (MFGM) and milk phospholipid (MPL) at the lipid droplet interface could be an effective strategy to improve the physicochemical properties and digestibility of infant formula emulsion (FE) systems that contain milk protein. The results showed that the distribution of lipid droplets became more uniform, and the adsorption of MFGM and MPL with different thicknesses was observed at the interface by adding different ratios of MFGM and MPL. Meantime, the stability of the FE was significantly increased than FE prepared by only protein-coated oil core, especially FE4 prepared by adding MFGM and MPL (1:3, w/w) as membrane components, the emulsifying activity index (48.28 m2/g) 2 /g) and emulsion stability index (73.08 min) reached the maximum. The emulsion prepared by phospholipid (PL) encapsulation oil core (FE5) exhibited lipid droplet aggregation and poor emulsion dispersion. The results of lipid digestion indicated that FE obtained with MFGM and MPL encapsulated lipid droplets maintained more PL ring structure similar to human milk structure during gastric digestion, which in turn promotes intestinal digestion of lipids by preventing the formation of protein aggregation. At the end of intestinal digestion, FE4 exhibited the highest lipolysis rate (86.48%) and release of free fatty acids (92.05 mu mol/mL). Overall, the addition of a suitable ratio of MFGM to MPL, especially MFGM/MPL (1:3, w/w), contributes to the creation of a thin PL interface structure similar to that of human milk. This could facilitate fat degradation and fatty acid release by regulating the lipid droplet interface.