Investigation of Gelatin Polypeptides of Jellyfish (Rhopilema esculentum) for Their Antioxidant Activity in vitro
Yong-Liang Zhuang1, Li-Ping Sun1, Xue Zhao2, Hu Hou2 and Ba-Fang Li2*
1Research Centre of Food Engineering, College of Chemistry and Engineering, Kunming University of Science and Technology, Kunming, CN-650224 Yunnan, PR China
2Department of Food Chemistry and Nutrition, College of Food Science and Engineering, Ocean University of China, Qingdao, CN-266003 Shandong, PR China
Article history:
Received October 8, 2009
Accepted February 2, 2010
Key words:
jellyfish, gelatin polypeptide, antioxidant activity, copper(II)-binding ability
Summary:
Jellyfish gelatin was hydrolyzed by different proteases to obtain antioxidative polypeptides. The gelatin hydrolysate obtained by progressive hydrolysis using trypsin and Properase E exhibited the highest hydrolysis degree and antioxidant activity. Three series of gelatin polypeptides (SCP1, SCP2 and SCP3) were obtained by ultrafiltrating the gelatin hydrolysate through molecular mass cut-off membranes of 10, 6 and 2 kDa, respectively. Amino acid composition analysis showed that SCP3 had the highest total hydrophobic amino acid content. The in vitro antioxidant tests demonstrated that SCP2 had the strongest hydroxyl radical and hydrogen peroxide scavenging activities and metal chelating ability, while SCP3 showed the highest reducing power, antioxidant activity in linoleic acid emulsion system and superoxide anion radical scavenging activity. The results support the feasibility of jellyfish gelatin as a natural antioxidant polypeptide provider, and enzymatic hydrolysis and ultrafiltration could be potent future processing technologies to utilize the abundant jellyfish resource.
*Corresponding author: 
++86 532 8203 1908
++86 532 8203 1908