Factors influencing the production and stability of xanthylium cation pigments in a model white wine system

Abstract

The influence of various wine parameters on the production and stability of xanthylium cation pigments in a wine-like medium is reported. The xanthylium pigments have an absorbance maximum in the visible region at 440 nm that is close to the measured absorbance used by the wine industry to indicate the browning of wine (i.e. 420 nm). The results of this study show that iron is more efficient than copper in both the colouration and production of xanthylium cation pigments in wine-like solutions of tartaric acid and (+)-catechin. The non-flavonoid caffeic acid can inhibit the accumulation of the xanthylium cation pigments, despite the presence of metal ions, and also influence the stability of..