CALCIUM-BINDING AND IRON-BINDING-CAPACITY OF DIFFERENT FRACTIONS FROMIN-VITRO PROTEOLYSIS OF CASEIN

Different fractions with caseinophosphopeptides obtained by tryptic hy drolysis, followed by anion exchange chromatography, show significant differences in their calcium- and iron binding capacity. Further, diff erences were found between the fractions obtained with immobilized try psin compared with dissolved trypsin. In particular, fraction B obtain ed using trypsin immobilisate shows marked deviations; here a lower ca lcium- and a higher iron binding capacity were established. The studie s yielded, hence, new findings which are not only of importance for th e nutritional evaluation of milk proteins, but also for the developmen t of infant formulae and dietetic products, such as iron-enriched milk , milk products and other milk protein-containing foods.