Interpretations of ultraviolet absorption in white wines

Abstract

Methods are described for the general analysis of total ultraviolet (u.v.) absorbing constituents of white wines. An elution profile, which is characteristic of the particular wine, is obtained by continuous monitoring of effluent from a dextran gel column at 280 nm. Surprisingly, about half of the total u.v. absorbance in the Riesling wine examined was found to be due to non-phenolic wine constituents, which are separately eluted in the gel column analysis. These are nucleotidic materials, to which little attention has previously been given in oenology. Data relating to the protein-tannin fraction, and to nucleotidic and phenolic constituents, are directly obtained by recording the wine elution profiles at 265, 280 and 320 nm. The interpretation of the elution curves and the significance and general utility of this new analytical method are discussed.