Effect of Oxalate and Urea upon Ultracentrifugation Properties of Raw and Heated Skimmilk Casein Micelles

Abstract

The effect of oxalate aud urea treatmeats upon casein micelles sedimented from raw and heated skimmilk was examined by ultracentrifugation, to determine the relative importance of calcium and hydrogen or hydrophobic bonds in determining their structure. A model was proposed for the native casein mieelle which consists of numerous loosely packed calcium easeinate complex units joined in association by a combination of calcium and colloidal calcium phosphate-citrate linkages. The colloidal calcium phosphatecitrate is considered to be distributed throughout the micelle rather than as a layer on its outer surface.