Abstract

The synergistic effect of glucoamylase and a -amylase on the hydrolysis of raw corn starch in an agitated bead reaction system was studied by investigating the changes of sugar profiles, the granular structure, particle size distribution, and X-ray diffraction pattern of residual raw corn starch. The enzymatic hydrolysis of raw corn starch was greatly enhanced by synergistic effect of glucoamylase and $\alpha$ -amylase. Even though the sugar profiles were mainly determined by the mixing ratio of glucoamylase and $\alpha$-amylase; raw starch was mainly converted to glucose directly without accumulation of any significant amount of oligosaccharides. The cavity formation and fragmentation phenomena of raw corn starch granule subjected to enzyme reaction were analyzed by means of SEM and the particle size distribution. The X-ray diffraction pattern of raw starch was not changed at the initial stage of reaction but slightly changed at the late stage of hydrolysis, which may be caused by the preferential degradation of amorphous region by enzymatic reaction, not by the destruction of microcrystalline structure of raw corn starch.

분쇄마찰매체효소반응계에서 glucoamylase와 Alpha-amylase의 보완작용에 의한 옥수수 생전분의 효소당화 mechanism을 규명코자, 분리.정제된 상기 효소의 혼합 비율에 따른 당화양상 및 생성당 조성, 전분입자 구조, 생전분입자의 particle size 분포, X-ray 회절양샹의 변화 등을 관찰하였다. 분쇄마찰매체 효소반응계에서도 효소를 분리하여 사용하였을 때보다 glucoamylase와 $\alpha$-amylase를 혼합사용할 경우 당화율이 크게 향상되었으며, 고순도의 glucose 생산에 적합한 두 효소의 혼합비율은 약 1:1-1:2(unit) 로 판명되었다.

Keywords

• Enzymatic hydrolysis;
• raw corn starch;
• agitated bead reaction system;
• glucoamylase and $\alpha$-amylase