18B-31 |
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B. LI, Dept. of Food Science and Human Nutrition, Clemson Univ., 224 Poole Ag. Center, Clemson, SC 29634, F. Chen, and X. Wang, Dept. of Genetics & Biochemistry, Clemson Univ., 101 Jordan Hall, Clemson, SC 29634. Phytochemical antioxidants have been studied intensively in last several decades due to the rich source of bioactive phytochemicals in nature and the academic and industrial momentum for finding novel pharmaceuticals for the health benefits to humans. In contrast, antioxidants from animal source have not been paid much attention. In this study, we aimed to find some novel antioxidative peptides using proteolysis, chromatographic techniques and antioxidant assays. Hydrolysates obtained from porcine collagen by protease treatment (pepsin, protease from bovine pancreas, protease from streptamyces and protease from bacillus spp) exhibited high antioxidant activity in a linolenic acid peroxidation system induced by Fe2+. The highest antioxidant activity of the hydrolysates at pH 7.0 obtained by a cocktail treatment of proteases was up to 175%, which was stronger than that of 1.0mg/ml BHT (93.5%). These hydrolysates also possessed strong 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and metal-chelating activity. However, enzyme types, proteolytic sequences and the hydrolyzing time had significant effect on the antioxidant activity of the collagen hydrolysates. Furthermore, two different peptides (labeled as P1 and P2) showing strong antioxidative activities were isolated from the hydrolysates by consecutive chromatographic methods including gel filtration on a Sephadex LH-20 column, ion-exchange chromatography on a DEAE-Sephadex A-25 column, and high-performance liquid chromatography on an ODS column. The antioxidative activities of the purified peptides were again confirmed by the linolenic acid method, DPPH and metal chelating assays. Their molecular masses and amino acid sequences were determined with an ESI mass spectrometer. The results indicate that the purified peptides from porcine collagen hydrolysate, especially the P2, are potent natural antioxidants which might have wide applications in food and pharmaceutical industries.
Session 18B, Food Chemistry: Antioxidant and bioactive agents
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |