EFFECTS OF SKIN FERMENTATION TIME ON THE PHENOLS, ANTHOCYANINS, ELLAGIC ACID SEDIMENT, AND SENSORY CHARACTERISTICS OF A RED VITIS-ROTUNDIFOLIA WINE

Noble muscadine grapes (Vitis rotundifolia) were harvested at two stag es of maturity (optimum, based on full color and flavor development an d pH below 3.3, and 14 days later) and either pressed immediately for a blush wine or fermented on the skins for two, four, or six days. Red wines from more mature grapes had greater color intensity and higher levels of anthocyanins, total phenols, and non-polymeric phenols. Wine s from the more mature grapes had higher levels of the 3,5-diglucoside s of peonidin (Pn) and malvidin (Mv), and lower levels of delphinidin (Dp), cyanidin (Cy), and petunidin (Pt). Maximum color and anthocyanin extraction occurred within four days of skin fermentation with the op timum maturity fruit, but continued through day six with later maturit y fruit. However, wines fermented on the skins for four or six days ha d less muscadine aroma intensity and were more astringent. Skin fermen tation time had little effect on the distribution of anthocyanins, alt hough the immediate press wines had lower levels of Dp and Mv and high er levels of Cy and Pn. Total, non-polymeric and polymeric phenol leve ls increased with increasing skin fermentation time, but the polymeric phenol levels and anthocyanin polymerization were generally low in al l wines.