Free radical scavenging capacity in the aging of selected red Spanish wines

Free radical scavenging capacity by the DPPH.. method and main physicochemi cal properties, polyphenols content by HPLC, color by a tristimulus colorim eter, and UV-vis spectra in the aging of selected red Spanish wines, were s tudied. As the wines age, they become darker (lower lightness, L*) and incr ease their hue angle (lower red color) as well as the ratio of absorbance a t 420 nm to that at 520 nm. Main polyphenolics identified in the samples we re tannic acid, oenin, and gallic acid. The antiradical efficiency of the s amples increased during aging, which could be related to an increase in the tannic acid concentration shown by the following correlationship: EC50 = 1 /(0.18 + 0.0011[tannic acid](mg/L)) with a correlation coefficient of 0.744 .