33F-9


Studies on the antioxidative activity of Graptopetalum paraguayense E. Walther

Y.-C. Chung1, S.-J. Chen1, C.-K. Hsu2, C.-T. Chang, and S.-T. CHOU1. (1) Food and Nutrition, Providence University, 200 Chung ¡V Chi Rd, Sa-Lu, 433, Taiwan, (2) Biological Science and Technology, Taichung Healthcare and Management University, 500 Liuo-Feng, Taichung, 413, Taiwan

This study was aimed to evaluate the antioxidative activities of water (GWE), 50% ethanolic (GE50), and 95% ethanolic (GE95) extracts from Graptopetalum paraguayense. The antioxidant activities, including the radical-scavenging effect, reducing power, and antioxidative effect on Fe/ascorbate-induced lipid peroxidation in a liposome model system, were studied in vitro. The results showed that GWE, GE50 and GE95 revealed the antioxidative characteristics including the abilities of radical scavenging, reducing, and lipid peroxidation inhibition. It was found that the antioxidative activities of all the extracts increased with the increase of their concentrations, and the activities correlated with both the total phenol and anthocyanin contents. A comparison of the half-inhibition concentration (IC50) values of different antioxidative reactions revealed that GE50 was more effective in scavenging a ,a-Diphenyl-b-pricryl-hydrazyl (DPPH) radical and showed higher reducing power than GWE and GE95. However, there was no significant difference in the lipid peroxidation-prevention effect among the extracts.

Session 33F, Nutraceuticals & Functional Foods: Antioxidants and phytochemical analysis
2:00 PM - 5:30 PM, Tuesday PM Room Hall N-1

2004 IFT Annual Meeting, July 12-16 - Las Vegas, NV