Studies on the Changes of the Milk Casein by Various Treatments:Part II. The Effect of Frozen Storage on the Milk Casein

A study has been made with the changes occurred in the milk casein during frozen storage. The flocculated protein formed during storage of frozen milk was resolved in 4 ~ 5 peaks in free-boundary electrophoretic pattern, using veronal buffer containing 7 m urea.The flocculated protein was mainly casein. It may be considered that portions of casein have undergone some modification or denaturation during the destabilization process.Significant increase has occurred in the relative proportion of β-casein in the casein remaining in supernatant after removal of flocculate, indicating that the partial fractionation of casein component occurred as a result of flocculation.