Anti-hypercholesteraemic and antioxidative activities of camel skin gelatin hydrolysate: effect of enzyme type, enzyme: substrate ratio and time of hydrolysis

Camel skin gelatin hydrolysate (CSGH) was prepared using different proteolytic enzymes [alcalase (A), protease (P) and their combination (AP (1:1))], hydrolysis time (2, 4 and 6 h) and enzyme: substrate (E/S) ratio (1%, 3% and 5%). In general, the degree of hydrolysis (DH) increased with increasing hydrolysis time for all enzyme treatments. CSGHs generated with alcalase showed significantly higher lipase (LP) inhibitory activity compared with protease-derived CSGH at all hydrolysis conditions (P < 0.05). Whereas higher cholesterol esterase (CE) inhibitory activity was observed with CSGH produced by protease (P < 0.05). However, when CSGHs were produced using AP, the highest LP and CE inhibitory activity were recorded at 3 and 1% E/S ratio during 2 and 4 h of hydrolysis, respectively (P < 0.05). Antioxidant assays revealed that CSGHs showed improved radical scavenging activities compared with native CSG (P < 0.05). Overall results indicated that CSGHs with higher in vitro anti-hypercholesteraemic and antioxidant activities could be obtained by enzymatic hydrolysis.