Functional Properties and Antioxidant Activity of Protein Hydrolysates from Crocodile Skin
ZHOU Ya-di;CHEN Sun-fu;BAO Yu-long;LUO Yong-kang
1. College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China；
2. Guangxi Mengzhan Crocodile Technology Development Co. Ltd., Nanning 530000, China
Abstract：This study explored functional properties and antioxidant activity of protein hydrolysates from crocodile skin. Two
commercial proteases, papain and alcalase, were used to hydrolyze crocodile skin under optimum reaction conditions. The effects
of protease type and hydrolysis time on degree of hydrolysis (DH), functional properties and antioxidant of protein hydrolysates
were examined. For both proteases, DH increased with hydrolysis time up to 4 h, but a higher maximum DH value was obtained
with alcalase. Protein hydrolysates obtained with both proteases did not show a significant difference in solubility (P＞0.05). At
the same DH, hydrolysis products with better heat stability at pH 4 were obtained with alcalase compared to papain. Ferrous
ion-chelating capacity of protein hydrolysates prepared with papain considerably increased with increasing hydrolysis period
up to 1 h and then reached a plateau without significant differences (P＞0.05). After 3 h of hydrolysis, protein hydrolysates
with higher ferrous ion-chelating capacity but weaker DPPH radical scavenging capacity were obtained with alcalase compared
to papain. Collectively, the above findings suggest that alcalase is more effective in hydrolyzing crocodile skin and yields
hydrolysis products with better emulsifying capacity and heat stability than papain. Protein hydrolysates from crocodile skin
have potent antioxidant activity and thus have great potential for development and utilization.
2012, Vol. 26 
