【摘要】 应用GHRH型热泵干燥机,研究了干燥温度、干燥风速、热烫时间、铺料密度对桑叶脱水特性的影响。单因素实验结果表明,桑叶干燥的较优铺料料量为1.0kg/m²,适当的热烫预处理能够起到护色和提高干燥速率的作用。从温度、风速、热烫时间三因素的中心复合表面实验得到,温度是影响干燥速率的显著因素,风速为次显著因素,热泵干燥对桑叶品质的影响较小,并得到了干燥速率的数学模型为Y=2.3103-0.0804X₁+0.0539X₂+0.0213X₃+0.0008X₁X₁-0.0094X₂X₂-0.0043X₃X₃。应用Minitab软件响应优化器优化工艺参数,当干燥温度为64.20℃、风速为2.40m/s、热烫时间为2.0min、干燥耗时2.25h时,所得产品蛋白质和黄酮含量为鲜桑叶的77.93%和69.75%,优化工艺的平均干燥速率为0.5532,与回归方程预测值的相对误差为2.38%。所得数学模型及最优工艺,对桑叶批量干燥生产有一定指导作用。更多还原

【Abstract】 A type of heat pump dryer named GHRH was used to study which the drying temperature, wind speed, blanching time and material density have effect on the dehydration of mulberry leaves. The single factor experiment results show that the dry mulberry better paving material is 1.0 kg/m², appropriate time of blanching pretreatment can protect color of product and improve the drying rate. Three factors such as temperature, wind speed, and blanching time were of the central composite surface experiment. The experiment acquired that temperature is the significant factors affecting the drying rate, wind speed is the secondary significant factor, heat pump drying have less affect on the quality of mulberry leaves, and the mathematical model of drying rate was obtained: Y =2.3 103-0.0 804X₁+0.0 539X₂+0.0 213X₃+0.0 008X₁X₁-0.0 094X₂X₂-0.0 043X₃X₃. Application of response optimizer of the Minitab software to optimize the process parameters are as follows : the temperature is64.20 ℃, the wind speed is 2.40 m/s, the blanching time is 2.0 min and the drying time of 2.25 hours. The protein and flavonoids of obtained product are 77.93% and 69.75% of fresh mulberry leaves, respectively. Average drying rate of optimization process is 0.5532, and the relative error between the predicted values by regression equations was 2.38%. It is the mathematical model and the optimal process that useful for guiding batch production of dry mulberry leaves.更多还原