36E-10 |
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K. ZHOU and L. Yu. Dept. of Nutrition & Food Science, Univ. of Maryland, 0112 Skinner Bldg., College Park, MD 20742-7521 Antioxidant properties of 17 samples of spinach, broccoli, green bean, kale, carrot, and rhubarb grown in Colorado were examined. The antioxidant properties of vegetable extracts were evaluated by their free radical scavenging activities against superoxide anion radical and cation radical ABTS. Chelating activity against Fe (II) and total phenolic content of each vegetable extract was also investigated. The results showed that all vegetables had significant antioxidant activities under experimental conditions, while different vegetables and different harvests of the same vegetable varied substantially in their antioxidant activities. Among the test vegetable samples, kale exhibited the highest cation radical scavenging activity with 42 - 58 umoles Trolox equivalents /g and the highest total phenolic contents with 16.3 - 18.8 mg Gallic acid equivalents/g. Rhubarb showed the greatest anion radical scavenging activity which quenched 96.3% superoxide anion at 0.4 mg/mL in react mixture. Broccoli had the highest chelating activity with 23.4 - 29.3 mg ETDA equivalents/g. However, carrot possessed the lowest anion and cation radicals scavenging activity and showed the weakest chelating activity as well as the lowest total phenolic contents. These data indicated that antioxidant properties of different vegetables varied substantially and kale, rhubarb, broccoli may provide more dietary antioxidants than carrot.
Session 36E, Fruit & Vegetable Products: General
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |