全脂米糠过氧化物酶挤压钝化参数研究

Extrusion Passivating Parameters of Peroxidase in Full-Fat Rice Bran

利用挤压稳定化方法处理全脂米糠,探索挤压加工参数对灭酶效果的影响规律。以挤压机机筒温度、物料含水率、螺杆转速、模孔直径为考察因素,过氧化物酶残余酶活力为评价指标,在单因素试验基础上进行响应面研究,试验结果表明,挤压工艺的因素排序为机筒温度>物料含水率>螺杆转速>模孔直径,在机筒温度135℃,物料含水率22.5%,螺杆转速130 r/min,模孔直径8 mm的挤压条件下,过氧化物酶残余酶活达到最小值0.53%,钝化效果较好,过氧化物酶残余酶活低于微波法,稳定化程度较高。SEM电镜结果显示,挤压处理使米糠的微观结构发生复杂变化,更加易于人体的消化吸收。

The full fat rice bran is processed by extrude stabilization method, and research the effect of extrusion processing parameters on enzyme inactivation degree. Barrel temperature, moisture content of material, rotation speed of screw and aperture diameter of extruding machine were considered as factors, the residual activity of rice bran peroxidase was employed as evaluation index. Basic on the single factor experiments conduct the response surface methodology, The results indicated that the barrel temperature was the biggest effect factor, and second was material moisture, the third was screw rotation speed, and the die head model was the smallest effect factor, when barrel temperature of extruded was achieved to 135 ℃ ,moisture content of material was reached 22.5%, rotation speed of screw was attained 130 r/min and the aperture diameter of extruding machine was 8mm. Under the optimal conditions, peroxidase hasgood passivation effect and the residual activity of rice bran peroxidase reaches the lowest 0.53 %, and compared with microwave heating on full fat rice bran, the extrude stabilization valve of residual activity of rice bran peroxidase was lower, therefore, the after - treatment full fat rice bran could be more stable. The scan- ning electron microscopy analyzed that extrusion processing has a complicated effect on the microstructure of rice bran, the extruded full fat .rice bran was more easily to digest and was absorbed by the human body.