Adsorption behavior at interface of oil-in-water emulsions prepared with mixtures of milk fat globule membrane proteins and polar lipids

Abstract

The milk fat globule membrane (MFGM) contains proteins and polar lipids making this complex mixture a good emulsifier. In this study, MFGM material was isolated from reconstituted buttermilk using microfiltration and further separated into MFGM protein concentrate and polar lipid concentrate using solvent fractionation. The emulsifying properties of those two emulsifier fractions, separately or in combination, at various concentrations of proteins (0.3; 1.3 and 2.3 w%) and polar lipids (0.3; 1.3 and 2.3 w%), were investigated. The results showed that at low emulsifier concentrations (< 2.3%), the combination of both proteins and polar lipids resulting in the formation of emulsions with a small droplets size and low apparent viscosity. The addition of polar lipids did not replace the adsorbed proteins. Between the two emulsifier fractions, MFGM protein concentrate had greater emulsifying properties compared to the polar lipid concentrate.