Changes in the polyphenolic and volatile content of “Fino” Sherry wine exposed to high temperature and ultraviolet and visible radiation

Experiments of accelerated oxidation of “Fino” Sherry wines have been conducted at different temperatures (25 and 45 °C) and under the influence of UV–Vis radiation (a xenon lamp of 1500 W). Two types of glass bottle were employed: topaz bottles (with low values of transmittance in the UV–Vis range) and transparent bottles. To identify significant differences between the wine before and after being subjected to the influence of these factors, the values of absorbance at 420 nm and the concentrations of various polyphenolic and volatile compounds were submitted to a multivariate variance analysis. The three factors “temperature”, “radiation”, and “time” had a statistically significant effect on the values of absorbance at 420 nm and on the concentration of most of the polyphenolic and volatile compounds, while the “bottle” factor was only significant for polyphenol content. All the wines showed losses in several polyphenolic compounds, which were more severe for the wines bottled in transparent glass. The combined application of high temperature and UV–Vis radiation provoked significant decreases in most of the volatile compounds monitored.