研究了在双螺杆挤压系统下应用高温型α-淀粉酶制备和改善膨化米粉冲调性能的工艺和方法,并比较了加酶挤压前后DE值、结块率、黏度、色泽的变化。结果显示,在挤压过程中添加高温型α-淀粉酶,可以提高原料淀粉的降解程度,产品在冲调复水时,膨化米粉的结块率降低。通过响应面优化实验,得到了添加高温型α-淀粉酶制备膨化米粉最佳挤压工艺条件:挤压温度136.2℃,螺杆转速100 r/min,加酶量36.35 u/g。在此条件下所得膨化米粉与未加高温淀粉酶的米粉比较,产品DE值由1.06上升到13.58,结块率由32.0%下降到11.25%,冲调后的黏度由113.9 mPa.s下降到88.6 mPa.s,产品色度△E值与对照样基本一致,冲调性得以改善。

Addition of thermo stable α-amylase during double screw extrusion cooking of rice was carried out and DE value,agglomeration rate,viscosity,colour with and without the addition of enzymes were studied.The results showed that the addition of thermo stable α-amylase could increase the degradation degree of starch.After dissolution,extruded rice powder had a lower agglomeration rate.Optimized parameters were obtained by response methodology as follows: terminal barrel temperature 136.2℃,screw rotating speed 100 r/min and enzyme concentration 36.35 u/g.Compared with the control samples,the rice powder obtained after optimization showed better solubility,DE value increased from 1.06 to 13.58,agglomeration rate decreased from 32.0% to 11.25%,the viscosity decreased from 113.9 mPa·s to 88.6 mPa·s,and the almost same color.