Hydrolysis of cow's and buffaloes whey proteins by some commercial proteolytic enzymes as affected by sodium and calcium chlorides

摘要

The effect of sodium chloride and calcium chloride on the enzymic hydrolysis of whey proteins was studied. Whey samples were prepared from cow and buffalo milk and were treated with rennet, Neutrase, fungal proteinase and Flavourzyme. Proteolysis was monitored by measuring quantities of non-protein nitrogen released during hydrolysis and by SDS-PAGE gel. The results showed that cow milk whey samples were susceptible to the tested enzymes in the order: Neutrase>Flavourzyme>fungal proteinase>rennet.Flavourzyme had the highest activity in the proteolysis of buffalo milk whey samples followed by fungal proteinase, Neutrase and rennet, respectively. The results indicated that NaCl had an inhibitory effect on the proteolysis of cow and buffalo milk whey samples by these enzymes. Flavourzyme exhibited a noticeable proteolytic action on both types of whey proteins even in the presence of 10% NaCl. Calcium chloride induced proteolytic action of rennet and Flavourzyme on cow milk whey proteins, and Neutrase and fungal proteinase on buffalo milk whey proteins. The proteolytic action of Neutrase and fungal proteinase on cow milk whey proteins and rennet and Flavourzyme on buffalo milk whey proteins were substantially reduced by CaCl2.