Oak barrel tannin and toasting temperature: Effects on red wine anthocyanin chemistry

Oak-derived compounds are generally considered to be important in red wine perception and color qualities. In this study, the percentage of loss and kinetic rates of degradation of monomeric anthocyanins as well as the formation of pigmented tannins were monitored in red wines aged for 8 and 12 months in oak barrels differentiated by stave ellagitannin content (low LTP, medium MTP and high HTP) and toasting level (160 and 180 °C as initial temperature). The malvidin coumaroyl glucoside is found to be the most reactive monomeric anthocyanin during barrel aging. While color intensity was not affected, the results indicated that in presence of high ellagitannin content red wines exhibit a lower loss and slower degradation of monomeric anthocyanins and slower formation of pigmented tannins.