STUDIES ON MICELLAR CALCIUM-PHOSPHATE - COMPOSITION AND APPARENT SOLUBILITY PRODUCT IN MILK OVER A WIDE PH RANGE

Calcium and phosphate concentrations in milk ultrafiltrate prepared at 37 °C over the pH range 4.0-8.0 have been measured and used to calculate the apparent solubility products for various calcium phosphates in milk. Micellar calcium phosphate had a constant Ca/Pi—1.58 ±0. 03 at all pH values and a near-invariant ion activity product for CaHPO4Apparent solubility products have also been obtained for brushite, hydroxyapatite and amorphous tricalcium phosphate in milk salt solution over a similar pH range. No evidence was found for a hydroxyapatite or amorphous tricalcium phosphate phase in milk. © 1984, Proprietors of Journal of Dairy Research 1984. All rights reserved.