Isolation of bovine milk fat globule membrane material from cream without prior removal of caseins and whey proteins

Abstract

SummaryBovine milk fat globule membrane (MFGM) material was isolated from cream by a new technique which did not involve removal of caseins and whey proteins before destabilization of the fat globules. These components were removed by centrifugation of the membrane material extract through a concentrated sucrose solution (52·5% (w/v) sucrose in 10 mM-Tris HCl buffer, pH 7·5). Membranes collected at the sample–sucrose interface, while whey proteins remained in the supernatant and caseins migrated into the concentrated sucrose solution. The yield of membrane material using this procedure was 25% less than that from conventional methods. This reduced yield was due mainly to lower levels of lipid material, in particular triglyceride. Electrophoretic analysis showed that the polypeptide composition of ‘unwashed’ membrane material was similar to that of conventionally prepared MFGM. This method is particularly suitable for the isolation of membrane material from milks and dairy products in which the fat globule stability is reduced or unknown.