Optimization of enzymatic hydrolysis process to prepare coix kernel juice

To obtain unique flavor, nutrient- rich coix kernel juice, baking experiment and amylase enzymatic hydrolysis process were carried out.First the baking experiment was conducted where baking temperature and time were chosen as influencing factors, and sensory evaluation score was selected as standard to judge the best conditions of baking.Then ratio between material and water, enzyme dosage, enzymolysis time, enzymolysis temperature, enzymolysis pH were chosen as influencing factors, and content of reducing sugar was selected as standard to reseach the best conditions of amylase enzymatic hydrolysis.Based on the results of single- factor experiments, orthogonal test were designed to optimize the best enzymatic process.The results showed that the optimum preparing conditions were:baking temperature of 160℃, baking time of 45 min, ratio between material and water (g ∶ mL) of 1 ∶ 10, enzyme dosage of 250U /g, enzymatic hydrolysis time of 3.0h, enzymolysis temperature of 60℃, enzymolysis pH of 6.5, under these conditions, the content of reducing sugar reached 1.4818g /100g in the coix kernel juice, which has milk white color, full-bodied smell and pure taste.