Evolution of Phenolic Compounds during Wine Fermentation and Post-fermentation: Influence of Grape Temperature

The evolution of different phenolic compounds during the first year of vinification of Monastrell wines as well as the influence of grape temperature at the moment of crushing on the quantitative composition and evolution of polyphenols were studied. Phenolic acids, hydroxycinnamic acid derivatives, anthocyanins, flavan-3-ols and flavonols were determined by HPLC. The results showed that temperature strongly influenced the rate of polyphenol extraction during the first three or four days of alcoholic fermentation but did so to a lesser degree as vinification progressed. At the end of the experiment, only caftaric and coutaric acids showed differences regarding the temperature of grapes at the moment of crushing.