Dissociation of Large and Small Bovine Casein Micelles by Dialysis

Casein micelles range from 30 to 300nm in diameter, and the composition of the micelles varies according to the diameter.1>2) Investigation of the micelle size is important for clarification of the micelle structure. Slattery and Evard3) reported that the protein composition of a subunit of a large micelle must be different from that of a small micelle. However, they did not take the salt content of micelles into consideration. It has been reported that the salt content varies with the micelle size,2'4) and that a large micelle becomes small particles through medium ones liberating salts on dialysis.5) Therefore, in order to clarify the correlation between large and small micelles, we investigated the change of micelle composition with dissociation by dialysis. Skimmilk containing less than 0.01% of fat was