挤压膨化对大麦全粉理化特性的影响

Effect of Extrusion on Physicochemical Properties of Whole Barley Flour

本文研究了双螺杆挤压膨化技术对大麦全粉理化特性的影响。结果表明,在优化工艺条件下(螺杆转速45 Hz、喂料速度35 Hz、套筒温度140℃、原料水分含量20%),挤压膨化所得的大麦膨化粉与膨化前相比,其水分含量、总淀粉含量、粗脂肪含量、蛋白质的含量分别下降了12.16%、6.89%、1.46%、1.38%;吸水指数和水溶指数分别上升了341%和7.98%,颜色加深;峰值粘度、最低粘度、最终粘度和回生值分别降低了3932.99、3036.93、5244.09和2206.81 cp,糊化温度由69.59℃下降至50.21℃,且无明显糊化过程。扫描电镜显微照片可见,挤压膨化后的大麦全粉的淀粉颗粒发生明显改变,各种物质都被均匀的聚合到一起,呈现出相互粘连呈片状的结构。

In this paper,the effects of twin-screw extrusion on the physical and chemical properties of barley flour were studied.Results showed that:Under the optimized process conditions(screw speed of 45 Hz,feed speed of 35 Hz,sleeve temperature of 140℃,raw material moisture content of 20%),the moisture contents,total starch contents,crude fat contents and protein contents of the extruded puffed flour decreased by 12.16%,6.89%,1.46%and 1.38%,respectively,compared with these before extrusion.The water absorption index and water solubility index increased 341%and 7.98%respectively,moreover,the color was deepened.The peak viscosity,the lowest viscosity,the final viscosity and the retrogradation value decreased by 3932.99,3036.93,5244.09 and 2206.81 cp respectively,and the gelatinization temperature decreased from 69.59℃to 50.21℃without obvious gelatinization process.Scanning electron microscopy showed that the starch granules of the extruded whole barley flour changed significantly,and all the materials were uniformly aggregated together,and showed a flake-like structure.