PT - JOURNAL ARTICLE AU - V. Schneider TI - Evaluation of Small Amounts of Flavonoid Phenols in White Wines by Colorimetric Assays AID - 10.5344/ajev.1995.46.2.274 DP - 1995 Jan 01 TA - American Journal of Enology and Viticulture PG - 274--277 VI - 46 IP - 2 4099 - http://www.ajevonline.org/content/46/2/274.short 4100 - http://www.ajevonline.org/content/46/2/274.full SO - Am J Enol Vitic.1995 Jan 01; 46 AB - For evaluation of flavonoid phenols in the low concentration range in white table wines, four colorimetric assays have been compared: (a) reaction with Folin-Ciocalteu reagent before and after precipitation of flavonoids in HCl-methanal (FC); (b) reaction with vanillin (VAN); (c) reaction with 4-(dimethylamino)-cinnamaldehyde (DAC); and (d) a rapid browning test at 60°C in oxidative medium (POM). There was a highly positive correlation between concentration units obtained by FC, VAN, and DAC, while POM is poorly correlated to concentration units. VAN and, to a lesser extent, FC lead to an overestimation of flavonoid content. DAC displays highest sensitivity and reproducibility. It appears most suitable for appreciation of oxidative aging potential in routine control.