18B-27 |
|
C.-H. LEE and K. L. Parkin. Dept. of Food Science, Univ. of Wisconsin, Madison, 1605 Linden Dr., Babcock Hall, Madison, WI 53706-1284 Reactive nitrogen oxide species (RNOS) are generated from the reaction of nitric oxide (NO) and oxygen. These RNOS have potentially deleterious effects on biological systems such as DNA fragmentation, inhibition of some enzymes involved in maintaining genetic integrity, and cellular damage. The identification of food components that can scavenge and diminish the potentially toxic effects of NO may provide a basis for improving health through diet. The objective of this study was to evaluate the NO scavenging activity of beetroot pigments. Two red beetroot strains, regular and high-pigmented, were used in this study. Peeled beetroots were lyophilized and ground into a fine powder. Powdered beetroot tissue (2.5g) was dissolved in water and then subject to Sephadex LH-20 chromatography. NO scavenging activities of pigmented fractions were assessed by a sodium nitroprusside generating NO system with analysis by the Greiss reagent. Up to 6 pigmented fractions were obtained from beetroot samples and the total yield of pigment recovery ranged from 80 to 90% by the Sephadex LH-20 chromatography. There were more pigmented bands from high pigment beet root shown on the Sephadex LH-20 column, compared to regular pigment beet root. All beet pigment fractions exhibited NO scavenging activity in a concentration-dependent response. The degree on NO scavenging ranged 54-98% and 31-96% by pigment fractions from regular and high pigment beet root, respectively, at over the 150 to 750 mg/ml range of pigment level tested. These results suggest that beet pigments may provide potential health benefits by through mitigation of pathological conditions caused by NO and RNOS. Further identification of specific pigments in beetroot extract conferring this bioactivity may lead to health-promoting and value-addition opportunities for beetroot resources.
Session 18B, Food Chemistry: Antioxidant and bioactive agents
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |