Hydrolysis Conditions for Porous Starch Preparation with Early-indica Rice by Compound Enzyming

Porous starch is a good carrier as many functional components in food or medicine industry.The preparation methods for porous starch using α-amylase and glucoamylase to hydrolyze early indica rice starch were presented. Main hydrolyzing factors such as temperature, pH value, time and quantity of the enzymes were investigated by statistical method. In each case, the best technique conditions for preparing porous starch were different for three response values: yield rate, water absorption and adsorption capacity of ponceau 4R. Based on the water absorption of porous starch, the best condition obtained from enzymatic experiment was the enzymatic temperature 55℃,pH 4.0 and hydrolyzing time 16 h, the ratio of α-amylase to glucoamylase in volume 1∶3,enzyme active 14.00 KNU/g,90.00 AGU/g,respectively. When validated twice under the optimized conditions, the porous starch yield rate was 41.07% and 43.37%, water absorption was 148.03% and 155.61%, adsorption capacity of ponceau 4R was 9.37 mg/g and 9.38 mg/g, respectively.