酶法联合压热-冷却循环处理制备抗性淀粉

Enzymatic Hydrolysis Coupled with Autoclaving-cooling Cycles for the Preparation of Resistant Starch

摘要:

本研究以玉米淀粉为原料，通过酶法联合压热-冷却循环处理制备抗性淀粉，测定酶解过程中淀粉的水解度（DE值）、脱支度和直链淀粉含量、样品抗性淀粉含量及其热稳定性，采用差示扫描量热仪（DSC）、扫描电子显微镜（SEM）分别测定抗性淀粉的热力学特性和颗粒形貌。结果表明，耐高温α-淀粉酶酶解能显著提高淀粉的水解度，耐高温α-淀粉酶联合压热-冷却循环制备的抗性淀粉含量为10.51%~12.16%；淀粉脱支度、抗性淀粉含量、直链淀粉含量随着普鲁兰酶酶解前压热-冷却循环处理次数增加而显著下降，抗性淀粉的热稳定性却得到提高；先普鲁兰酶酶解后压热-冷却循环处理3次得到的抗性淀粉含量最高，达到17.94%；抗性淀粉的糊化峰值温度为119.5 ℃~121.1 ℃，糊化焓随抗性淀粉含量的增大而增大，颗粒形状为不规则的碎石型。

Abstract:

Maize starch was used as raw material to prepare resistant starch by enzyme method coupled with autoclaving–cooling cycles. Hydrolysis and debranching degree of starch, amylose content, resistant starch content and thermodynamic stability were detected in the experiment. The thermodynamic characteristics, particle morphology of resistant starch were analyzed by differential scanning calorimeter (DSC) and scanning electron microscope (SEM), respectively. The results showed that the hydrolysis degree of starch was increased significantly after enzymolysis of thermostable α-amylase. Resistant starch content of coupled thermostable α-amylase with autoclaving-cooling cycles was 10.51% to 12.16%. Debranching degrees, resistant starch and amylose content were declined significantly with autoclaving-cooling cycles increasing before digestion of pullulanase, but thermal stability of the resistant starch was increased. The resistant starch content reached the highest value (17.94%) after digestion of pullulanase before three times processing of autoclaving-cooling cycles. Gelatinization peak temperature of resistant starch was from 119.5 ℃ to 121.1 ℃. The gelatinization enthalpy was increased with resistant starch content increasing, and the granule shape of resistant starch was of irregular gravel type.