Effects of Seed Tannins on Enzymatic Decolorization of Wine pigments in the Presence of Oxidizable Phenols

摘要

Red pigments were isolated from skins of Cabernet Sauvignon grapes and flavonoidphenols were isolated from their seeds. Red table wine was produced form the same lot of grapes. Three red pigment fractions- monomeric anthocyanins, oligomeric pigments, and polymeric pigments-were fractionated by successive extraction with isoamly alcohol and 1-butanol. The extraction of anthocyanins with isoamy alcohol was signifi- cantly inhibited by SO_2 present in the wine, but the interference by SO_2 was removed by the addition of acetal- dehyde. Seed phenols were fractionated into four fractions-catechins, dimeric phenols, oligomeric tannins, and polymeric tannins-by partition chromatography.