酶法修饰对莲子粉黏度及复水性的影响

采用α- 淀粉酶对莲子粉中的淀粉进行适度水解降低其黏度，提高冷冻干燥的效率，并探讨黏度与复水性之间的关系。在研究酶解时间、温度、pH 值及酶添加量对莲子粉水解液黏度影响的基础上，通过正交试验优化确定最佳酶水解条件为酶添加量16.56U/mL、温度70℃、时间15min、pH6.5，水解液的黏度为77mPa·s，解液DE 值4.95%。4 个因素都对试验结果有极显著的影响(P ＜ 0.01)。同时发现黏度与复水性之间呈现负相关关系，并且酶解和冷冻干燥对莲子粉的复水性有显著影响(P ＜ 0.05)。

Effect of Enzymatic Modification on Viscosity and Rehydration of Lotus Seed Powder

In freeze-drying process, the heat transfer efficiency of high-starch fruit-vegetable juice is reduced due to its high viscosity. In this study, α-amylase was used to appropriately hydrolyze the starch in lotus seed powder to reduce its viscosity, improve the freeze-drying efficiency and explore the relationship between viscosity and rehydration. Based on the effects of hydrolysis time, hydrolysis temperature, pH and enzyme amount on the viscosity of lotus seed powder, the optimal enzymatic hydrolysis conditions were achieved by orthogonal experiments to be enzyme amount of 16.56 U/mL, hydrolysis temperature of 70 ℃, hydrolysis time of 15 min and pH 6.5. The viscosity of hydrolyzate was 77 mPa·s and its DE value was 4.95%. Four factors had a significant impact on results (P ＜ 0.01). At the same time, the viscosity of lotus seed powder was negatively correlated with the rehydration property. Therefore, enzymatic hydrolysis and freeze-drying had a significant influence on rehydration property (P ＜ 0.05).