"The whey protein was hydrolysed by trypsin, and the separation of peptides, the properties of hydrolysates and the analysis of the ability to inhibit the formation of calcium phosphates were then investigated. Calcium-binding peptides were produced by tryptic hydrolysis of whey protein concentrate and further purified by precipitation and chromatography on DEAE-cellulose. The hydrolysates were loaded onto an ion-exchange column, followed by stepwise elution with 0, 0.25, 0.5 and 0.75m NaCl in equilibration buffer to separate the peptides. Trypsin hydrolysates were shown to peak with 0.25m NaCl and 0.5m NaCl. The results of SDS-PAGE analysis showed that the peptides with a small molecular weight of about 1.4-3.4 kDa were present in the fraction resulting from 0.25m and 0.5m NaCl stepwise elution by ion-exchange chromatography of tryptic hydrolysates," wrote X.U. Rui and colleagues.

The researchers concluded, "The results of this study show that the whey protein hydrolysates produced by the action of trypsin have the ability to inhibit the formation of calcium phosphates."

Rui and colleagues published the results of their research in International Journal of Dairy Technology ("Calcium Binding of Peptides Derived from Enzymatic Hydrolysates of Whey Protein Concentrate." International Journal of Dairy Technology, 2009;62(2):170-173).

For additional information, contact X.U. Rui, NE Agriculture University, Key Laboratory Dairy Science, Minist Education, College Food Science, Harbin 150030, People's Republic of China.

From the July 6, 2009, Prepared Foods E-dition