Studies on the Colloidal Proteins of Skimmilk. II. The Effect of Heat and Disodium Phosphate on the Composition of the Casein Complex

Summary The molar ratio of calcium to phosphorus in the so-called colloidal calcium phosphate of the casein complex was calculated to be approximately 1.5 in raw skimmilk. This ratio was reduced to 1.25 when 0.15% Na 2 HPO 4 was added before heating to 88° C. for 15 minutes, indicating that some diphosphate was formed. The composition of the sedimented complex with respect to calcium, phosphorus, and nitrogen was practically constant regardless of particle size. The calcium in the serum phase was reduced to about one-third its original value by adding 0.15% Na 2 HPO 4 before preheating skimmilk.