Stabilnost proantocijanidina vina tijekom starenja u boci

Chemical changes of proanthocyanidins that occur during production, maturation and aging have a great impact on wine quality. Namely, proanthocyanidin fraction represents the most abundant phenolic fraction in red wine that is responsible for wine astringency and bitterness perception. This study aimed to investigate stability of total proanthocyanidins and individual flavan-3-ol monomers [(+)-catechin, (-)-epicatechin] and dimers (B1, B2, B3, B4) in Cabernet Sauvignon wine, during 12 months of aging in reductive conditions in bottles. Changes in concentrations of total proanthocyanidins were determined spectrophotometrically, while the changes in the concentration of individual flavan-3-ols were determined using high performance liquid chromatography (HPLC/FLUO). Obtained results showed decrease in the concentrations of total proanthocyanidins and flavan-3-ols during aging, as well as significant differences in the stability among analyzed compounds. (+)-Catechin showed higher sta-bility and lower reactivity than (-)-epicatechin. Among procyanidins dimers analyzed, stability de-creased in order B3, B2, B4, B1. Flavan-3-ol dimers showed higher stability on chemical changes during 12 months of aging in bottles than flavan-3-ol monomers.