O/W Emulsion Stabilized by Bovine Milk Phospholipid–Protein Nanoemulsions: Preparation, Stability, and In Vitro Digestion

This study aims to prepare a stable oil-in-water (O/W) emulsion with droplets of approximately 3–5 μm and a structured phospholipid (PL)-protein membrane that is similar to human milk fat globules. A nanoemulsion with an average droplet size of 200 nm prepared with bovine milk PL-protein, a milk fat globule membrane (MFGM)-rich ingredient, was used as an emulsifier to form an O/W emulsion with an average droplet size of 3.96 μm. Stable O/W emulsions were formed with a low concentration (1 wt %) of the MFGM-rich ingredient. The nanoemulsion was adsorbed at the oil–water interface. The O/W emulsions stored at 4 °C did not show structural damage upon 7 days of storage. The deformation or partial deformation of nanoemulsion droplets attached to lipid droplets may contribute to the physical stability of the emulsion. In vitro digestion of the O/W emulsion showed a low lipolysis degree in gastric digestion, and the final hydrolysis efficiency of the O/W emulsion was 62.74%, which is higher than that of traditional infant formula.