The glucose and ethanol concentrations in the liquid samples were measured through HPLC,and a refractive index detector. The mobile phase was deionized water at a flow rate of 0.6 mL/min at 85 °C. Concentration of the ethanol produced through the distillation process was measured using a density/specific gravity meter (DA-510, KEM Co., Ltd., Japan). The concentration of the anhydrous ethanol was measured using a Karl–Fisher moisture titrator (MKC-520, KEM Co., Ltd., Japan).