Figure 3
From: Liberation of recalcitrant cell wall sugars from oak barrels into bourbon whiskey during aging
β-1,4-glucans and crystalline cellulose are disrupted by charring and are eliminated after aging from the C Layer. Confocal microscopy images of the C layer stained with Calcofluor White to show β-1,4-glucans (A,C,E) and Pontamine S4B to show crystalline cellulose (B,D,F). Panels A and B show the presence of β-1,4-glucans and crystalline cellulose in the C layer before the stave has been charred. Panels C and D show that disruption of β-1,4-glucans and crystalline cellulose occurred during charring. In panels E and F, no fluorescence was detected, indicating a loss of β-1,4-glucans and crystalline cellulose from the C layer following aging.
