Effect of temperature on the salt balance of milk studied by capillary ion electrophoresis.

Many inorganic species, such as calcium, phosphate and magnesium, are in equilibrium between the liquid and colloidal phases of milk and hence are of importance with respect to the coagulation properties of milk. Capillary ion electrophoresis makes possible the determination of anions and cations in less than 6 min. The soluble phase of milk was obtained by ultrafiltration and samples had to be diluted 250-fold before analysis. Cold storage increased soluble calcium and phosphate concentrations, and warm-up of the milk restored the initial ionic equilibria. More drastic heat treatments (80-90 degrees C) caused precipitation of tricalcium phosphate and calcium citrate.