应用双螺杆挤压机改性玉米蛋白质的研究

Study on Modification of Maize Protein by Twin-screw Extruder

本文采用BC45型双螺杆挤压机,进行了玉米粗蛋白的挤压改性研究。通过分析蛋白质水溶性的变化,发现螺杆转速越快,物料水分越低,膨化温度越低,模头长度越短,越有利于获得高NSI的玉米蛋白。并用均匀试验设计优化了影响蛋白质溶解性的工艺条件;获得高NSI的最优挤压条件为:物料水分11%,螺杆转速160rpm,膨化温度75℃,模头长度300mm;各因素对玉米粗蛋白NSI的影响次序为:物料水分、膨化温度、模头长度、螺杆转速。蛋白质经过挤压膨化处理,可大大改善其功能性质指标,与此同时产品的色泽、气味也得以改善,消化利用率提高。

The crude maize protein in extrude modification were studied by BCA5 twin - screw extruder in this paper. The changes of solubility water of proteins were analyzed and summarized. The lower the moisture of the meals, the lower the expanding temperature, the shorter the die length and the faster the rotate speed of screw was the greater the benefit was done on the harvest of maize proteins with high NSI were investigated;Besides, uniform design was applied to study the process technical condition of the solubility of protein; the optimal conditions to obtain high NSI are the moisture of meals 11%, the rotate speed of screw 160 rpm, the expanding temperature 75 ℃, the die length 300m; the effect of every factors on meal NSI is in order of decrease,the moisture of meals, the expanding temperature, the die length, and the speed of screw. These modification methods can obviously improve the functional properties of the crude maize proteins, such as solubility water absorption, foaming capacity emulsibility and gelation etal. Meanwhile the flavour and colour of protein products can be improved and the digestibility can also be improved through the extrusion process.