Ellagitannins in Woods of Spanish, French and American Oaks

The variability of ellagitannin composition and its molecular weight distribution in unseasoned oak heartwood of four species grown in the North of Spain (Quercus robur, Q. petraea, Q. pyrenaica and Q. faginea) and in samples of Allier, Limousin and American oak were studied to know the differences in composition between Spanish oakwoods and oakwoods traditionally used in cooperage. The heartwood was processed into sawdust and total polyphenols, condensed tannins, and total ellagitannins were determined. Ellagitannins were analyzed by HPLC and GPC. Finally, the average, standard deviation, coefficient of variation and discriminant functions were calculated.