Properties of Acid Casein and Casein Micelles from Milk Destabilized by Frozen Storage

Abstract

No difference was found in calcium sensitivity, electrophoretic and optical properties between acid caseins prepared from skimmilk before and after frozen storage (up to 180 days at -7°C).
Destabilization of casein micelles can not be explained either by the reduction of solvation of the micelles or by the liberation of k-casein from the micelles. However, when storage period was extended (about six months), splitting of a part of k- and β-casein from the micelles to soluble form was observed, suggesting a drastic change of structure of the destabilized casein micelles.