Resveratrol Concentration in Muscadine Berries, Juice, Pomace, Purees, Seeds, and Wines

Abstract

The presence of resveratrol has been confirmed in <i>Vitis vinifera</i> and <i>Vitis labrusca</i> grapes and in both red and white wines, but not in the seeds. Since there is a lack of information regarding resveratrol in muscadine grapes (<i>Vitis rotundifolia</i>), two studies were conducted using bronze- and dark-skinned muscadines produced with cultural practices similar to those used in commercial vineyards. The first study determined resveratrol concentrations in the whole berries, berries without seeds, and seeds alone; the Second study quantified resveratrol in selected muscadine products including wine, unfiltered juice, pomace, and purees made from pomace. We established that resveratrol is a natural constituent of bronze- and dark-skinned muscadine grapes. Dark-skinned muscadine products had higher concentrations of resveratrol than the bronze-skinned counterparts, but there was no significant difference between the two color groups except in the pomace. Even though muscadine grape seeds had a higher concentration of resveratrol than the other parts of the berry, the seeds contributed only 30.1% and 23.4% of the total resveratrol in bronze- and dark-skinned berries, respectively. Muscadine wines compared favorably in resveratrol concentration with <i>V. vinifera</i> and <i>V. labrusca</i> wines reported in the literature. The consumption of muscadine products (<i>e.g.</i>, wine, unfiltered juice, whole berries without seeds and, especially, products made with muscadine purees) could be a means for incorporating a significant quantity of resveratrol in the average diet.