PT - JOURNAL ARTICLE AU - V. Cheynier AU - I. Hidalgo Arellano AU - J. M. Souquet AU - M. Moutounet TI - Estimation of the Oxidative Changes in Phenolic Compounds of Carignane During Winemaking AID - 10.5344/ajev.1997.48.2.225 DP - 1997 Jan 01 TA - American Journal of Enology and Viticulture PG - 225--228 VI - 48 IP - 2 4099 - http://www.ajevonline.org/content/48/2/225.short 4100 - http://www.ajevonline.org/content/48/2/225.full SO - Am J Enol Vitic.1997 Jan 01; 48 AB - The concentration of phenolic compounds during fermentation of Carignane musts exposed to air or protected from oxidation during pumping over operations was monitored by HPLC in order to evaluate the influence of oxidation in red wine making. All phenolic compounds accumulated during the first 3 to 8 days of maceration, due to extraction from the solid parts of the grapes. At this stage, yeasts consumed all the available oxygen so that phenolic compounds were protected from oxidation. When the yeast activity decreased, enzymatic oxidation of polyphenoloxidase substrates (caffeoyltartrate and p-coumaroyltartrate) and coupled oxidation of o-diphenols by the enzymically generated caffeoyltartrate quinones took place, resulting in approximately 20% losses of these compounds in the air exposed sample.