Effect of heating of cream on the properties of milk fat globule membrane isolates

Buttermilk contains large amounts of proteins derived from skim milk and from the milk fat globule membrane (MFGM). Heating the cream before churning, even at temperatures as low as 65 degrees C, strongly affected the functional properties of the membrane fraction and caused whey proteins to associate with the MFGM. The extent of this interaction depended on temperature. Pasteurization temperature of the cream had no effect on the emulsifying properties of whole buttermilk isolates, the casein content of which masked changes in the MFGM fraction. The stability of oil-in-water emulsions made using isolated MFGM material depended on the heat treatment of the cream. The solubility, color, iron content, amount of whey protein present in the MFGM isloate, and emulsifying properties of this material were all affected in parallel by the heat treatment.