Influence of the botanical origin and toasting level on the ellagitannin content of wines aged in new and used oak barrels.

The influence of the botanical origin (French oak: Quercus petraea and American oak: Quercus alba) and different toasting levels (light, medium and heavy) on the ellagitannin content of wines aged in oak barrels has been studied. This took place in two consecutive vintages in order to study what happens after the barrels have been already used for one year with another wine. This study was carried out with two red wines (Cabernet Sauvignon) and with two decolored white wines (Macabeo) from vintages 2012 and 2013 in order to work with a simpler matrix which facilitates chemical analysis. The results show that the botanical origin, toasting level and the number of times that the barrels have been used exert a major influence on the final ellagitannin concentration. In general, the behavior of all the individual ellagitannins was very similar to that described for the total ellagitannins. Briefly, the levels of total ellagitannins concentration in the decolored white wine aged for 12months in new French barrels ranged between 31.2mg/L in the lightly toasted and 4.7mg/L in the heavy toasted. In contrast, these levels were quite lower in American new barrels ranging between 3.6mg/L and 0.9mg/L. Finally, the total ellagitannin concentration decreased an average of 63% in the wines aged in the one year used barrels.