Antioxidant, tyrosinase and urease inhibitory activities of camel αS-casein and its hydrolysate fractions

The aim of this study was to investigate the effect of pancreatic enzymes hydrolysis of camel alpha S-casein on their antioxidant, tyrosinase and urease inhibitory activities. Isolated aS-casein was hydrolyzed, fractionated and assayed for their antioxidant properties by using four complementary tests; namely, ABTS(center dot+) scavenging, hydroxyl radical scavenging, ferrous ion chelating and beta-carotene-linoleic acid assays. The in vitro enzymatic inhibitory activity was determined by using L-DOPA as a substrate and indophenol method for tyrosinase and urease inhibitory activity, respectively. After enzymatic hydrolysis, the activities were significantly increased whereas chymotryptic hydrolysis released peptides with higher activity than trypsin. The obtained fraction with low molecular weight (< 10 kDa) exhibited the highest antioxidant and enzymatic inhibitory activities. Results suggested that antioxidant properties of peptides affect their tyrosinase inhibitory activity. This study reveals that camel milk alpha S-casein is as a great candidate for incorporation into functional foods to help in preventing disorders caused by oxidative reactions in food and human body's.