CASEIN PHOSPHOPEPTIDES IMPROVE ZINC AND CALCIUM-ABSORPTION FROM RICE-BASED BUT NOT FROM WHOLE-GRAIN INFANT CEREAL

Background: Casein phosphopeptides (CPP) are phosphorus-rich peptide f ragments of casein, assumed to contribute to the high bioavailability of calcium from milk. Methods: The effect of casein phosphopeptides on calcium and zinc absorption from infant foods was investigated. Twent y-two men and women were given single test meals extrinsically labeled with Ca and Zn. Absorption was calculated from measurements on whole- body retention of the radioisotopes. Each subject was given either ric e-based cereal (n=11) or whole-grain cereal (n=11) on three occasions together with 250 ml water and added 0, 1, and 2 g CPP in random order . One serving of rice-based cereal contained 481 mg Ca and 1.29 mg Zn; whole-grain cereal contained 541 mg Ca and 1.77 mg Zn. One and 2 g of CPP contributed with additional 69 and 138 mg Ca, respectively. Resul ts: From rice-based cereal, fractional calcium absorption was not affe cted by CPP addition (mean+/-SD): 16.0+/-4.0% (no CPP), 17.6+/-4.5% (1 gCPP), and 15.8+/-4.3% (2 g CPP), while the total quantity of calcium absorbed was significantly improved: 7+/-19 mg, 97+/-25 mg, and 98+/- 26 mg, respectively (p=0.0004). Fractional zinc absorption as well as total quantity of zinc absorbed were increased with addition of CPP: 1 9.4+/-9.0% (0.25+/-0.12 mg), 25.2+/-7.5% (0.33+/-0.10 mg) and 23.9+/-5 .4% (0.31+/-0.07 mg) at the three CPP levels (p=0.04). From whole-grai n cereal, CPP had no effect on the percentage or actual quantity of ca lcium absorbed: 17.0+/-3.2% (92+/-18 mg), 17.2+/-4.5% (105+/-27 mg), a nd 15.0+/-4.6% (102+/-31 mg), respectively. Zinc absorption was also n ot influenced by CPP: 16.0+/-5.1% (0.28+/-0.09 mg), 15.3+/-3.1% (0.27/-0.06 mg) and 18.1+/-4.4% (0.32+/-0.08 mg), respectively. Conclusions : CPP addition improved calcium and zinc absorption from rice-based ce real, while no effect was seen from whole-grain cereal.