Author(s): Gallier, S., D. Gragson, R. Jimenez-Flores, D.W. Everett
Journal: International Dairy Journal (2012) 22 (1): 58-65.
Phospholipid-protein monolayer films were studied as model systems to mimic the structure of the native bovine milk fat globule membrane (MFGM) and to understand lipid-protein interactions at the surface of the globule. Phospholipids extracted from bovine raw milk, raw cream, processed milk and buttermilk powder were spread onto the air-water interface of a Langmuir trough, beta-casein was then added to the sub-phase, and Langmuir-Blodgett films were studied by epifluorescence microscopy and atomic force microscopy. In all films, beta-casein was responsible for clustering of the sphingomyelin- and cholesterol-rich microdomains into larger platforms. This suggests that the same phenomenon may happen at the surface of the milk fat globule, where specific MFGM proteins may cause aggregation of microdomains.