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

Abstract

The presence of resveratrol has been confirmed in Vitis vinifera and Vitis labrusca 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 (Vitis rotundifolia), 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 V. vinifera and V. labrusca wines reported in the literature. The consumption of muscadine products (e.g., 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.