均质及大米蛋白对大米淀粉糊化和质构特性的影响

Effect of Homogenization Treatment and Rice Protein on Pasting and Texture Properties of Rice Starch

利用均质机在20~100 MPa压力下处理大米淀粉(RS),在添加或不添加大米蛋白(RP)情况下,考查大米淀粉理化性质、糊化和质构特性的变化。研究结果表明:随着处理压力的增加,RS的溶解度、膨胀率和透光率分别从1.90%、3.37%、6.27%上升至2.88%、5.38%、14.17%,凝沉性则下降;添加大米蛋白后,同一处理压力下,淀粉的溶解度、膨胀率下降,凝沉性上升。糊化特性分析发现,均质处理后,RS的最终黏度、崩解值和回生值分别下降了17.75%、24.47%和16.45%,说明其热稳定性提升,抗老化能力增强;原淀粉和60 MPa压力处理后的淀粉在添加氯化钠后糊化温度上升,黏度、降落值、回生值均有所下降,添加大米蛋白后淀粉黏度下降,回生值上升。质构特性分析发现,随处理压力的增加,淀粉凝胶的硬度从1 743 g下降到1 398 g,弹性则变化不大,大米蛋白使淀粉的硬度下降而弹性升高。

The present research investigated the effect of homogenization treatment(20~100 MPa) on the physicochemical property, pasting properties and texture properties of rice starch(RS) with or without rice protein(RP). The results showed that the solubility, swelling power and light transmittance of RS were increased from 1.90%, 3.37%, 6.27% to 2.88%, 5.38%, 14.17%, respectively, with increasing treatment pressure.The retrogradation of RS was gradually decreased. RP resulted in the decline of the solubility, swelling power and the growth of retrogradation of RS under the same treatment pressure. The pasting properties results showed that after treatment, the final viscosity, breakdown and setback of RS were decreased by 17.75%, 24.47% and 16.45%, respectively. It indicated that samples had higher thermal stability and lower retrogradation rate. After adding sodium chloridize, the peak temperature of both the native starch and starch by treatment under pressure of 60 MPa(RS60) was increased, while the value of viscosity breakdown and setback were decreased. After adding rice protein, starch viscosity decreased and the setback value rose. The texture properties results showed that the hardness of starch gel was decreased from 1 743 g to 1 398 g and the springiness was not obviously changed as treatment pressure rose. Finally, RP caused a decrease in the hardness of starch and an increase in elasticity.