Effect of hydrolysis reaction time on the reducing sugar yield of Tacca (Tacca involucrata) and Tigernut (Cyperus esculentus) starch for Bioethanol production

摘要

The effect of hydrolysis reaction time on the reducing sugar yield of Tacca (Tacca involucrata) and Tigernut (Cyperus esculentus) 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 1.0, 2.0, 3.0 and 4.0 ml/g for Tacca and slurry concentrations of 3.5, 4.0, 4.5 and 5.0 ml/g for Tigernut. The starch content of the feedstocks determined the quantity of water used. They were hydrolyzed using malted barley as enzyme at enzyme concentrations of 0.1g/g to 0.3g/g at durations ranging from 1½ - 3½ h and even 4h. 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.