Investigations on the isolation of milk fat globule membrane proteins from cream and buttermilk

Components of the milk fat globule membrane (MFGM), such as proteins are reported to have functional properties. Cream and buttermilk are sources rich in MFGM material and, thus, investigated in this study to isolate MFGM proteins. The combination of casein precipitation of buttermilk and the subsequent diafiltration of the buttermilk whey resulted in a more effective extraction of MFGM proteins in comparison to the commonly used method of cream washing. Additionally, an analytical method based on the stain free SDS-PAGE was further developed. MFGM proteins were quantified in buttermilk and butter serum and conclusions were drawn about the content of membrane proteins in native milk fat globules.