Figure 5
From: Liberation of recalcitrant cell wall sugars from oak barrels into bourbon whiskey during aging
Hemicellulose content declines during aging in the C layer. For the C and O layers of a new, five-, six-, and ten-year-old barrel, and for the P and R Layers of a ten-year-old barrel, neutral monosaccharides were measured by HPLC-PED after hemicellulose hydrolysis with TFA. Bars represent the sum of all measured monosaccharides. Charring induced a slight reduction in hemicelluloses which was not statistically significant. Whiskey maturation appears to have a greater effect on the hemicellulose content with the C layer of the ten-year-old barrel exhibiting a significant reduction compared with a new barrel stave. A Tukey-Kramer multiple comparison test was used to determine statistical significance (n = 12; different letters denote statistically significant differences at P < 0.05; error bars indicate standard error).
