大米淀粉及其不同取代度磷酸酯淀粉的糊化和流变特性

Pasting and Rheological Properties of Rice Starch and Starch Phosphate with Different Degrees of Substitution

粳米淀粉与磷酸二氢钠发生酯化反应,通过改变反应温度得到取代度分别为0.028、0.049、0.073和0.14的磷酸酯淀粉。使用快速黏度分析仪和流变仪对比测定粳米淀粉及具有不同取代度的磷酸酯淀粉的糊化和流变特性。快速黏度分析仪测定的糊化特性显示PO43-与淀粉的结合降低了淀粉的糊化温度,升高了淀粉的峰值黏度,与粳米淀粉相比,磷酸酯淀粉更不易回生。流变仪测定的流变特性显示高取代度的磷酸酯淀粉抗剪切,随着取代度的增加,凝胶硬度降低,凝胶黏性增强。

Rice starch phosphate with substitution degrees of 0.028,0.049,0.073 and 0.14 were obtained through esterification reaction between rice starch and sodium dihydrogen phosphate at different temperatures.The pasting and rheological properties of rice starch and starch phosphate with different degrees of substitution（DS） were determined using rapid viscosity analyzer（RVA） and rheometer.Results showed that the incorporation of phosphate in rice starch resulted in reduced pasting temperature and increased of viscosity.Compared to rice starch,rice starch phosphate exhibited better anti-retrogration property.In addition,starch phosphate with high DS had high capacity to resist shearing force and declined pasting hardness and enhanced pasting viscosity.