Characterisation of the Colour Fraction of Pedro Ximenez Andalusian Sweet Wines

Changes in colour fraction of commercially bottled Pedro Ximenez sweet wines, unaged and oxidatively agedin American oak casks and mostly produced in the Montilla-Moriles and Jerez-Xérès-Sherry Designations ofOrigin (Spain), have been studied. The total tannin content and the total polyphenol content (A280) increasedwith increased aging time, a trend clearly observed in the Jerez wines. Browning, as measured by the absorbanceat 420 nm, differed markedly between unaged and aged wines. Aged wines showed an increase in browning withtime and an increase in high molecular weight browning compounds, most probably Maillard compounds.Colour measurements based on the CIELab system showed a gradual decrease in hue and lightness with ageing