中性蛋白酶与超声波结合分离稻米淀粉及其黏滞性研究

Rice Starch Isolation by Neutral Protease and High-intensity Ultrasound

用中性蛋白酶与超声波结合提取稻米淀粉,并用快速黏度分析仪测定稻米淀粉的黏滞性。结果显示,用中性蛋白酶提取稻米淀粉时,稻米淀粉的提取率为62.3%～73.8%,淀粉中蛋白质含量为3.74%～4.88%;蛋白酶与超声波结合时稻米淀粉的提取率为72.1%～77.2%,蛋白质含量为0.68%～1.30%,破损淀粉含量显著降低,两者结合的最佳条件是酶先作用3h,再50%超声波作用40min。中性蛋白酶与超声波结合处理所得淀粉的黏滞谱中,峰值黏度、消减值和最终黏度都比单独酶解所得淀粉的高,而崩解值降低;与碱处理淀粉比,也是峰值黏度、消减值和最终黏度升高,崩解值降低,这说明超声波作用没有破坏淀粉性质。中性蛋白酶与超声波结合是提取稻米淀粉的有效方法。

The neutral protease and high- intensity ultrasound were combinedly used to isolate the rice starch, which viscosity was analyzed by Rapid Visco Analyzer（RVA）. The results showed that the starch yield was 62.3%-73.8% with 3.74%-4.88% residual protein content by neutral protease alone, and 72.1%-77.2% with 0. 68%-1. 30% residual protein content by the combination of neutral protease and high-intensity ultrasound. Damaged starch content greatly decreased after sonication. The preferred combination was neutral protease digestion for 3 h followed by sonication at 50% amplitude for 40 min. The protease peak viscosity, setback viscosity and final viscosity of rice starch increased and breakdown viscosity of rice starch decreased after the combinations, which were the same to the alkaline treatment. This indicated that the high-intensity ultrasound produced no damage to starch properties. The combination of neutral protease and high intensity ultrasound was an effective technique for isolation of rice starch.