The disaggregation of calcium-depleted casein micelles.

The effect of depletion of Ca2+ on the composition and size distribution of casein micelles in milk has been examined using chemical analysis, size exclusion chromatography, fast protein liquid chromatography, turbidimetry and photon correlation spectroscopy. Partial removal of Ca2+ by EDTA and subsequent dialysis resulted in disaggregation of some of the casein micelles; as the EDTA concentration increased, the proportions of Ca2+ and phosphate relative to protein in the micelles remaining intact decreased. However, the composition of the intact micelles, with respect to the different caseins, and the number-frequency size distribution were essentially unchanged.