CPG-chromatography studies of the stability of casein micelles

Casein micelles fractionated on controlled pore glass (CPG-10/3000) were shown to be stable by recycling experiments. Only minor effects on the size distribution of the casein micelles were found after heating skim-milk to 100 degrees C for 10 min, or freeze-drying skim-milk at -70 degrees C followed by resuspension in the synthetic milk serum of Jenness & Koops (1962). The heating caused some whey proteins (beta-lactoglobulin) to enter the micelle fractions while the freeze-drying caused some of the largest micelles to disrupt. In colloidal calcium phosphate-free skim-milk prepared according to Pyne & McGann (1960) all the micelles appeared to dissociate into monomeric caseins.