Evaluation of enzymatic hydrolysis via alcoholic fermentation of corn flour

Abstract

Abstract The research was concerned with the enzymatic hydrolysis followed by alcoholic fermentation of corn flour. Commercial corn flour purchased from local market contained starch of 87.25%, moisture 11.86% and ash 0.70%. The kinetics of corn flour hydrolysis was performed at 50°C, 65°C and 80°C using commercial thermos table-∞-amylase and ∞-amyloglucosidase. During hydrolysis the residual starch content was decreased with increasing hydrolysis time. The line weaver- Burk plot for enzyme hydrolysis of corn starch for 2.5%, 5% and 10% flour solution showed a Km value of 2.46, 2.27 and 1.73 mg/ml and Vmax values 1.23, 1.21 and 0.96 U/ml for 50°C, 65°C and 80°C respectively. Thin layer chromatography (TLC) was used to detect the presence of dextrose in the hydrolyzates. The Rf (Retention factors) values showed that the starch was mainly composed of dextrose and depended on carrier solvent use for dextrose assessment. When 100% ethyl alcohol used as carrier solvent the Rf value was 0.72 and ethyl alcohol: ethyl acetate= 1:1 the Rf value was 0.65. Both corn flour solution and its enzymatic hydrolysates were fermented with commercial baker’s yeast. Both the cases starch content was decreased and alcohol content was increased during hydrolysis and alcohol production was 3 times more from hydrolysates. The results obtained here will be useful for further research in the production of other value added products like white vinegar from the produced alcohol from con flour.