Impact of cream washing on fat globules and milk fat globule membrane proteins

Milk proteins, contained within the aqueous phase surrounding fat globules, should be removed before analysis of the composition of the native milk fat globule membrane (MFGM). The effect of the conditions applied during washing of cream on MFGM integrity has not been fully studied, and factors potentially effecting a modification of MFGM structure have not been systematically assessed so far. In this study, a cream separator was used to investigate the impact of cream washing on milk fat globule stability and the corresponding loss of MFGM proteins. Flow velocity, fat content, and type of washing solution were varied. Particle size measurements and protein analyses were carried out after each washing step to determine fat globule coalescence, removal of skim milk proteins, and efficiency of MFGM isolation. Significant differences in fat globule stability and protein amount in the MFGM isolates were measured using different washing conditions.