Intestinal Protein Digestion and Mineral Bioavailability with Special Reference to Casein Phosphopeptide on Ca Absorption

The solubility of a mineral is a principal criterion for its bioavailability. This property within the small intestinal tract may be markedly affected by a dietary protein source which forms a small amount of macropeptides; the latter interact with minerals having different strength of affinity. Such ligand formation between peptide and mineral cations usually lowers the absorption of minerals. However, in some instances—casein phosphopeptide (CPP) for example—a ligand with cation rather enhances absorption. The relationship in the affinity of mineral ions between ligand and the epithelial mucosal membrane is very important in considering the intestinal mineral absorption.