Composition and emulsifying properties of a milk fat globule membrane enriched material

The milk fat globule membrane (MFGM) contains proteins and phospholipids with potential technological functionalities. The emulsifying properties of MFGM fragments concentrated from reconstituted buttermilk using microfiltration (MF-BM) were compared with those of buttermilk powder (BMP), skim milk powder (SMP) and sodium caseinate (SC). Oil-in-water emulsions stabilised with MFGM fragments, at identical total protein/soybean oil ratios, were prepared using a two-step homogeniser at pressures of 0/2, 3/2, 9/2, 15/2 and 21/2 MPa. Above 15/2 MPa, droplet aggregation was observed with BMP or SMP emulsions, whereas no aggregation was observed with MF-BM emulsions. MF-BM emulsions prepared at 9/2 MPa showed a monomodal particle size distribution with an average droplet size of about 3.5 μm, significantly smaller compared with BMP and SMP emulsions. Emulsion viscosity depended on emulsifying materials and homogenisation pressures. Sodium caseinate emulsions showed poor stability. These results indicate the potential of MF-BM as emulsifiers for the development of new products.