Stability of Frozen Milk

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Abstract
Lactose crystallization apparently has a nonlinear relation with the volume of the casein precipitate. A study showed that the caseinate system suddenly destabilized when 85 to 90% of the lactose was in the alpha form. The time required to reach this critical stage was longer when samples contained sucrose, but not so when they contained sorbitol. The inhibiting effect of sucrose addition was attributed to retardation of the rate of lactose crystallization. Seeding greatly accelerated lactose to crystallization in all samples, resulting in earlier destabilization. For study of any changes taking place in the serum and casein-bound phosphorus, the milk from a cow injected with p32 was separated, condensed, and stored at 12[degree]F. A slight progressive increase in the total P as well as p32 contents of the serum indicates that bound phosphorus was slowly dissociated from the casein micelles into the serum, but it would be difficult to prove whether this is a cause or an effect of the destabilization reaction.