响应面分析法优化棉粕膨化工艺参数

Response surface analysis method for optimizing cotton meal puffing process parameters

试验旨在探求改变膨化加工工艺参数对游离棉酚含量和棉粕品质的影响,并筛选得到最优的膨化工艺参数。试验采用响应面分析法,采用MY56双螺杆挤压膨化机为加工设备,选取游离棉酚(FG)、蛋白体外消化率(IVPD)、蛋白溶解度(PS)、水溶性指数(WSI)和吸水性指数(WAI)为评价指标,调质后棉粕水分含量、主机螺杆转速、模头温度作为试验因素,通过中心组合设计响应面分析法对棉粕的膨化工艺进行了研究和优化,最终确定棉粕挤压膨化的最佳工艺参数。结论:①调质后游离棉酚的含量随着螺杆转速的增加而显著升高,随着物料水分含量的增加而显著增加,随着膨化机模头温度的升高而降低;蛋白体外消化率随着模头温度的升高呈现缓慢升高的趋势,随着物料水分的降低呈先降低后升高的趋势;且各因素对棉粕中FG含量的影响强度顺序为螺杆转速>物料水分>模头温度,对棉粕蛋白体外消化率的顺序为模头温度>物料水分>螺杆转速。②调质后物料水分17.6%、主机螺杆转速35 Hz(210 r/min)、模头温度132℃时棉粕膨化效果最好。此时膨化棉粕游离棉酚含量为69.88 mg/kg,蛋白体外消化率为68.93%,蛋白溶解度为40.92%,水溶性指数为17.04%,吸水性指数为2.80。

The purpose of the experiment was to explore the effect of changing the process parameters of extrusion process on free gossypol content and cotton meal quality,and to select the best extrusion process parameters.The test used Response surface methodology,using MY56 twin screw extruder as the processing equipment,selecting free gossypol(FG),protein in vitro digestibility(IVPD),protein solubility(PS),water solubility index(WSI)and water absorption(WAI).The index is the evaluation index.After conditioning,the moisture content of the cotton meal,the screw speed of the main machine,and the die temperature are used as the test factors.The central composite design Response surface methodology is used to study and optimize the expansion process of the cotton meal.The best process parameters for meal extrusion.Conclusion:①The content of FG increased significantly with the increase of the screw speed,increased with the increase of the moisture content of the material,and decreased with the increase of the temperature of the extruder die;The in vitro digestibility of protein with the temperature of the die,with the decrease of the moisture of the material,the trend of decreasing first and then increasing;And the effect of various factors on the FG content in cotton meal is in the order of screw speed>material moisture>die temperature,the order of in vitro digestibility of meal protein is die temperature>material moisture>screw speed.②When the moisture content of the quenched and tempered material is 17.6%,the screw speed of the main machine is 35 Hz(210 r/min),and the temperature of the die head is 132℃,cotton meal has the best extrusion effect.At this time,the free gossypol content of the expanded cotton meal was 69.88 mg/kg,the protein digestibility in vitro was 68.93%,the protein solubility was 40.92%,the water solubility index was 17.04%,and the water absorption index was 2.80.