EXTRACTION OF ELLAGITANNINS FROM OAK WOOD OF MODEL CASKS

Eight experimental model casks were constructed using wood from four o ak trees and filled with a 12 % ethanol solution for 200 days. The con centration of ellagitannins was subsequently measured in the solutions and in the inner and outer faces of the cask wood. Only a low proport ion of the total ellagitannins was extracted from the wood, and this p roportion varied significantly between both different casks and betwee n the eight ellagitannins measured. The two most abundant ellagitannin s, castalagin and vescalagin, were the least easily extracted. The con centration of ellagitannins was much lower in the solutions than expec ted from calculations based on the difference between the inner and ou ter faces of the wood. This degradation of ellagitannins occurs subseq uent to their extraction into solution.