Fractionation and utilisation of corn fibre carbohydrates

Corn fibre contains starch, cellulose, hemicellulose, lignin, oil, protein, etc. The separation and the utilisation of its carbohydrate components were studied. A 99.8% of the starch was removed by a two-step enzymtic hydrolysis. The remaining solid fraction was pretreated with alkali (2.5% NaOH) and alkaline peroxide (2.5% NaOH, 0.6% H2O2), in order to isolate corn fibre gum (CFG). The highest yield could be obtained under the most severe conditions (alkaline peroxide, 120 °C, 120 min). Following the pretreatment 51.3% of the corn fibre gum could be isolated by alcoholic precipitation from the soluble fraction. The solid fraction was used as carbon source for cellulase enzyme fermentation and as substrate for enzymatic hydrolysis. A 30% higher filter paper activity was obtained using pre-treated corn fibre as carbon source compared to the activities reached on original and destarched corn fibre. However, 15% higher filter paper activities were obtained on Solka Floc than on the pre-treated corn fibre samples. The enzymes produced were used for the hydrolysis of the pre-treated corn fibre substrate. The results of hydrolysis were compared to the performance of industrial enzymes. After 24 h of hydrolysis, the carbohydrate yields showed that the enzyme produced on pre-treated corn fibre could degrade the corn fibre substrate approximately 15% more efficiently.