SOLUBLE AND LIPID-BOUND CALCIUM AND ZINC DURING PROCESSING OF INFANT MILK FORMULAS

Samples were withdrawn during the manufacture of infant formulas to de termine steps which may affect soluble and lipid-bound Ca and Zn, whic h were estimated after centrifugal separation of in vitro digested sam ples. Pasteurization did not significantly reduce solubility of Ca and Zn. Blends forewarmed at low temperature contained a smaller proporti on of soluble Ca than skim milk, but Zn was not affected. Forewarming at high temperature reduced solubility of Ca. The solubility of Ca and Zn was lower in sterilized and spray-dried formulas than in blends fo rewarmed at low temperature. Though initial Ca and Zn levels were grea ter in infant formulas than in human milk, percentages of soluble Ca a nd Zn were not higher.