Analysis of anthocyanin pigments in Vitis vinifera (cv. Cabernet Sauvignon) and Vitis rotundifolia (cv. Noble) red wine

Red wines of varying skin contact times were made from Cabernet Sauvignon and Muscadine (cv. Noble) grapes and stored for two years. A new liquid chromatographic method to fractionate the anthocyanin pigments into four distinct fractions was developed to fractionate the wines. The resulting fractions were analyzed by UV/VIS spectrophotometric, circular dichroism and high pressure liquid chromatographic means to further identify their structure and composition. Cabernet Sauvignon wine pigments were shown to display distinct skin contact effects while the Noble pigments did not. Evidence was presented to show that the Cabernet Sauvignon pigment complexes are planar in structure and that the Noble pigments are vertically stacked. Earlier reports have indicated that wines from Noble grapes fade in color more rapidly than those made with Cabernet Sauvignon grapes. The differences in secondary pigment structure reported here are theorized to be the critical difference to account for the difference in the long term stabilities of wines made from the two grapes.