The effect of hydrolysis reaction time on the reducing sugar yield of Acha (Digitaria exilis) and Finger millet (Eleusine coracana) starch for bioethanol production was studied. The starches were extracted from the feedstocks by wet and dry milling methods. They were gelatinized at slurry concentrations of 2.0, 2.5, 3.0 and 3.5 mL/g for Acha and slurry concentrations of 2.5, 3.0, 3.5 and 4.0 mL/g for finger millet. They were then hydrolyzed using malted barley as enzyme at enzyme concentrations of 0.1g/g to 0.3g/g at durations ranging from 1½ - 3½ h. The results showed that for the two starches studied, none achieved highest reducing sugar yield at 1½ - 2½ h. The optimum fell largely between 3 to 3½ h. Overall results indicate that reducing sugar quantity is largely dependent on slurry concentration (mL/g) of starch, hydrolysis reaction time and even temperature.
Hydrolysis reaction time, Enzyme concentration, Reducing sugar yield, Bioethanol production, Finger millet, Acha