title: Casein phosphopeptides improve zinc and calcium absorption from rice-based but not from whole-grain infant cereal.
abstract: BACKGROUND
  Casein phosphopeptides (CPP) are phosphorus-rich peptide fragments 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. Twenty-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 rice-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.
  
  
  RESULTS
  From rice-based cereal, fractional calcium absorption was not affected by CPP addition (mean +/- SD): 16.0 +/- 4.0% (no CPP), 17.6 +/- 4.5% (1 g CPP), 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: 19.4 +/- 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-grain cereal, CPP had no effect on the percentage or actual quantity of calcium absorbed: 17.0 +/- 3.2% (92 +/- 18 mg), 17.2 +/- 4.5% (105 +/- 27 mg), and 15.0 +/- 4.6% (102 +/- 31 mg), respectively. Zinc absorption was also not 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 cereal, while no effect was seen from whole-grain cereal.
authors.affiliation: Research Department of Human Nutrition, LMC-Centre for Advanced Food Studies, Royal Veterinary and Agricultural University, Frederiksberg, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Hansen
authors.forename: B
authors.initials: B
authors.lastname: Sandström
authors.forename: M
authors.initials: M
authors.lastname: Jensen
authors.forename: S S
authors.initials: SS
authors.lastname: Sørensen
mesh_terms: D000328:Adult; D001682:Biological Availability; D002118:Calcium / Q000493:pharmacokinetics* / Q000652:urine; D002132:Calcium Radioisotopes; D002364:Caseins / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007223:Infant; D007225:Infant Food; D007408:Intestinal Absorption; D008297:Male; D012275:Oryza; D010446:Peptide Fragments / Q000494:pharmacology; D010748:Phosphopeptides / Q000008:administration & dosage / Q000494:pharmacology*; D014908:Triticum; D015032:Zinc / Q000493:pharmacokinetics*; D015037:Zinc Radioisotopes
chemical_list: D002132:Calcium Radioisotopes; D002364:Caseins; D010446:Peptide Fragments; D010748:Phosphopeptides; D015037:Zinc Radioisotopes; D015032:Zinc; D002118:Calcium