Antioxidant capacity and phenolic content of grapes, sun-dried raisins, and golden raisins and their effect on ex vivo serum antioxidant capacity.

Grapes and raisins provide phenolic antioxidants, which contribute to their potential health benefits. The objectives of this study were to compare the antioxidant capacity and phenolic content of green Thompson seedless grapes (the most common variety of grapes consumed in the United States), sun-dried raisins, and golden raisins (both produced from Thompson seedless grapes) and to observe the effects of their consumption over 4 weeks in 15 healthy human males with a cross-over design. The oxygen radical absorbance capacity (ORAC) (positive statistical significance for grapes after 2 weeks and golden raisins after 3 weeks), serum oxidation (positive statistical significance for golden raisin lag time after 4 weeks), total phenolics (no significant effects), and C-reactive protein (no significant effects) were monitored. Immediately postconsumption, there were some significant nonpositive changes. It is hypothesized that these negative results may be explained by postprandial oxidation, a known effect after carbohydrate consumption. Golden raisins had the highest antioxidant capacity and phenolic content. The consumption of a serving of grapes or raisins each day, in addition to a typical diet, may not be sufficient to overcome postprandial oxidation when consumed with other high carbohydrate foods but may have beneficial antioxidant effects over time.

[1]  Gerard Krewer,et al.  Phenolic content and antioxidant capacity of muscadine grapes. , 2003, Journal of agricultural and food chemistry.

[2]  A. Ferro-Luzzi,et al.  Alcohol-free red wine enhances plasma antioxidant capacity in humans. , 1998, The Journal of nutrition.

[3]  W. Stahl,et al.  Nutritional, dietary and postprandial oxidative stress. , 2005, The Journal of nutrition.

[4]  J. German,et al.  Inhibition of in vitro human LDL oxidation by phenolic antioxidants from grapes and wines , 1996 .

[5]  J. Espín,et al.  Varietal differences among the polyphenol profiles of seven table grape cultivars studied by LC-DAD-MS-MS. , 2002, Journal of agricultural and food chemistry.

[6]  V. Cheynier,et al.  HPLC Separation and Characterization of Flavonols in the Skins ofVitis viniferavar. Cinsault , 1986, American Journal of Enology and Viticulture.

[7]  C. F. Timberlake,et al.  The Procyanidins of White Grapes and Wines , 1979, American Journal of Enology and Viticulture.

[8]  M. Mutanen,et al.  No difference in platelet activation or inflammation markers after diets rich or poor in vegetables, berries and apple in healthy subjects , 2004, European journal of nutrition.

[9]  F. Ursini,et al.  Postprandial Oxidative Stress , 2002, Biological chemistry.

[10]  D. B. Zilversmit.  Atherogenesis: a postprandial phenomenon. , 1979, Circulation.

[11]  W. E. Hillis,et al.  The phenolic constituents of Prunus domestica. I.—The quantitative analysis of phenolic constituents , 1959 .

[12]  G. Beecher,et al.  Lipophilic and hydrophilic antioxidant capacities of common foods in the United States. , 2004, Journal of agricultural and food chemistry.

[13]  Vernon L. Singleton,et al.  White Wine Phenolics: Varietal and Processing Differences as Shown by HPLC , 1983, American Journal of Enology and Viticulture.

[14]  R. Wrolstad,et al.  Influence of Sugar on Anthocyanin Pigment Stability in Frozen Strawberries , 1990 .

[15]  S. Booth,et al.  Increases in human plasma antioxidant capacity after consumption of controlled diets high in fruit and vegetables. , 1998, The American journal of clinical nutrition.

[16]  P. Moldéus,et al.  Analysis of lipoprotein diene formation in human serum exposed to copper. , 1993, Free radical research communications.

[17]  A. Jaworski,et al.  Fractionation and HPLC determination of grape phenolics , 1987 .

[18]  A. Dávalos,et al.  Extending applicability of the oxygen radical absorbance capacity (ORAC-fluorescein) assay. , 2004, Journal of agricultural and food chemistry.

[19]  J. Folts,et al.  Grape juice, but not orange juice or grapefruit juice, inhibits human platelet aggregation. , 2000, The Journal of nutrition.

[20]  G. Beecher,et al.  Development of a database for total antioxidant capacity in foods: a preliminary study , 2004 .

[21]  N. Gheldof,et al.  Antioxidant capacity of honeys from various floral sources based on the determination of oxygen radical absorbance capacity and inhibition of in vitro lipoprotein oxidation in human serum samples. , 2002, Journal of agricultural and food chemistry.

[22]  R. Durst,et al.  Polyphenolic composition of raisins. , 2000, Journal of agricultural and food chemistry.

[23]  G. Aldini,et al.  Effect of a standardized grape seed extract on low-density lipoprotein susceptibility to oxidation in heavy smokers. , 2003, Metabolism: clinical and experimental.

[24]  O. Rebolledo,et al.  Postprandial hyperglycemia and hyperlipidemia-generated glycoxidative stress: its contribution to the pathogenesis of diabetes complications. , 2005, European review for medical and pharmacological sciences.

[25]  P. Bowen,et al.  Postprandial lipid oxidation and cardiovascular disease risk , 2004, Current atherosclerosis reports.

[26]  V. Cheynier,et al.  Polymeric proanthocyanidins from grape skins , 1996 .

[27]  F. Ursini,et al.  Grape seed proanthocyanidins prevent plasma postprandial oxidative stress in humans. , 2002, Journal of agricultural and food chemistry.

[28]  N. Gheldof,et al.  Buckwheat honey increases serum antioxidant capacity in humans. , 2003, Journal of agricultural and food chemistry.

[29]  K. Miwa,et al.  Inhibition of human low-density lipoprotein oxidation by flavonoids in red wine and grape juice. , 1997, The American journal of cardiology.

[30]  C. Barroso,et al.  Study of the polyphenol content of red and white grape varieties by liquid chromatography-mass spectrometry and its relationship to antioxidant power. , 2003, Journal of chromatography. A.