【摘要】 【目的】探讨胡萝卜切片远红外干燥的最优工艺参数,研究不同干燥条件对胡萝卜干制品平均干燥速率、单位能耗和品质指标的影响.【方法】以干燥温度、切片厚度和辐照距离为试验因素进行胡萝卜的远红外干燥特性试验,利用Weibull分布函数对胡萝卜切片的远红外干燥过程进行模拟,比较不同干燥条件下胡萝卜干制品的指标变化.【结果】干燥温度、切片厚度和辐照距离对胡萝卜的干燥特性曲线均有显著的影响;Weibull分布函数拟合的决定系数R²值均在0.98以上,离差平方和χ²值均很小;尺度参数α随着干燥温度、切片厚度和辐照高度的增加而呈现减小的趋势,形状参数β大于1;估算有效水分扩散系数D_cal在0.435×10^-7 ～3.080×10^-7 m²/s之间,有效水分扩散系数D_eff在1.542×10^-9 ～5.011×10^-9 m²/s之间,均随着干燥温度、切片厚度和辐照高度的增加而增大;对比不同干燥条件下干制品的总色差值、单位能耗和平均干燥速率,发现远红外干燥技术对总色差值的影响不显著,对单位能耗和平均干燥速率的影响显著.对比热风干燥和远红外干燥方式下干制品的微观结构,发现远红外干燥可以增加物料内部微孔道的数量,提高干燥速率.【结论】Weibull可以较好地描述胡萝卜的远红外干燥过程,远红外干燥技术可以改善胡萝卜干制品的品质,减少单位能耗,缩短干燥时间.更多还原

【Abstract】 【Objective】 In order to explore the optimal process parameters of far-infrared drying of carrot slices,study the effects of different drying conditions on the average drying rate,energy consumption and quality index of dried carrot products.【Method】 The drying temperature,slice thickness and irradiation height were used as the test factors for the far-infrared drying characteristics of carrots.The Weibull distribution function was used to simulate the far-infrared drying process of carrot slices,and the index changes of dried carrot products under different drying conditions were compared.【Result】 Drying temperature,slice thickness and irradiation height have significant influence on the drying characteristic curve of carrot.The coefficient of determination of R² of Weibull distribution function is above 0.98,the square of dispersion and the value of χ² are small;the scale parameter α decreases with drying temperature,slice thickness and irradiation height increasing,the shape parameter β is greater than 1;the estimated effective water diffusion coefficient D_cal is between 0.435×10^-7 and 3.080×10^-7 m²/s,and the effective water diffusion coefficient D_eff is 1.542×10^-9～5.011×10^-9 m²/s,both increase with drying temperature,slice thickness and irradiation height.Compared with the total color difference,unit energy consumption and average drying rate of dry products under different drying conditions,it is found that far-infrared drying technology has no significant effect on total color difference,and has significant influence on unit energy consumption and average drying rate.The microstructure of dry products in dry and far infrared drying mode,found that far infrared drying can increase the number of micropores inside the material and increase the drying rate.【Conclusion】 Weibull can describe the far infrared drying process of carrot,far infrared drying technology can improve the quality of dried carrot products,reduce energy consumption,and shorten drying time.更多还原