Production of Caseinophosphopeptides from Na-Caseinates Prepared from the Milk of Several Species by a Proteinase of Lactobacillus helveticus PR4

The aim of this work was to produce caseinophosphopeptides (CPPs) from Na-caseinates prepared from the milk of six species (bovine, sheep, goat, pig, buffalo, human) hydrolyzed by a partially purified proteinase from Lactobacillus helveticus PR4 and to characterize the CPP preparations by RP-FPLC (reversed-phase fast-protein liquid chromatography) and for calcium solubilizing/binding activity. The yield of CPPs ranged from 0.60 to 1.86% of the original proteins. The calcium-solubilizing activity varied from 2.5 (human CPPs) to 11.4 (buffalo CPPs) mg Ca²⁺ mg^-1 CPP. Moreover, minor differences in calcium-binding ability between the CPP from different species were observed. This work showed that CPPs with different calcium-solubilizing activity can be produced from various Na-caseinates by a Lb. helveticus proteinase. Milks having casein-fractions with similar amino acid sequences (e.g., sheep and goat), showed CPPs with the same activity. The data generated in this study show the potential of different caseins to yield CPPs and may help in the selection of milk for the production of functional foods enriched in CPPs.