为了提高花椒的干燥速率和干燥品质,寻求花椒真空干燥的最佳工艺参数组合。采用单因素试验,分别考察温度X1(50、60、70℃)、真空度X2(-0.06、-0.04、-0.02 MPa)、装载量X3(30、40、50 g)对花椒干燥特性的影响程度和各因子的合理范围,在此基础上选取干燥速率(Y1)、总色差(Y2)、开口率(Y3)为评价指标,设计三元二次回归旋转试验,利用Design-Expert软件进行响应面分析,分别建立3个指标的回归模型并进行单目标优化。利用响应面分析因素之间交互作用对各指标的影响程度,最后利用加权评分法将3个模型综合为一个模型并利用SPSS软件进行优化,得到最佳工艺优化参数组合为:X1=62.18℃、X2=-0.054 MPa、X3=37.23 g,此时干燥速率(Y1)为0.056 2 g/min,总色差(Y2)为1.315 2,开口率(Y3)为98%,与单目标优化结果接近,模型可靠。

In order to improve the drying rate and drying quality of Zanthoxylum bungeanum and optimal vacuum drying parameters,single factor experiment was used at temperature X_1(50,60,70℃),vacuum X_2(-0.06,-0.04,-0.02 MPa),loading X_3(30,40,50 g) on the drying characteristics and their reasonable ranges.Based on the single factor experiment,three factors quadratic design of rotary combination was established by drying rate(Y1),total chromatic aberration(Y_2),and aperture ratio(Y_3) as indicators.Response surface analysis was carried out by Design-Expert software,the regression models were built by three indexes and optimized single target.Finally,using the weighted scoring method combined three models into a comprehensive model.After optimization of the model,the optimal process parameters are:X_1= 62.18℃,X_2=-0.054 MPa,X_3= 37.23 g.Under the above conditions,the drying rate(Y_1) was 0.058 9 g/min,the total chromatic aberration(Y_2) was 1.3152,the opening rate(Y_3) was 98%.The results were similar with the single target optimization which indicated that the model is reliable.