番木瓜热风干燥特性分析

Hot air drying characteristics and model of papaya

探讨不同干燥温度和不同切片厚度条件下番木瓜的热风干燥特性。通过9种数学模型对番木瓜热风干燥试验数据进行拟合，结果表明：同大多数农产品干燥一样，番木瓜热风干燥主要为降速过程。不同干燥温度和物料厚度番木瓜热风干燥的水分有效扩散系数D∥的变化范围分别是1．7984×10-8～3．3233×10-8，0．5793×10-8～2．8522×10-8m2／s，由此可以看出番木瓜热风干燥的水分有效扩散系数随着干燥温度和物料厚度的增大而增大；Page模型是番木瓜热风干燥过程的最适模型，平均R2值、SSE值、RMSE值和X2值分别为0．9981，0．0033，0．0124，0．0002。经回归分析，得到温度、厚度与有效水分扩散系数Deff的关系表达式。研究结果可以为生产实践中预测番木瓜热风干燥的水分变化提供参考。

In order to provide a theoretical basis for industrial application of hot air drying for papaya, the drying characteristics were studied in different hot air drying temperatures （60, 70, 80, 90 ℃ ） and in different slice thicknesses （4, 6, 8, 10mm）. By fitting the experimental data to nine mathematical models, the results showed that： as same as the most results of agricultural products drying test, hot air drying of papaya chips mainly occurs in the falling rate drying period. The effective moisture diffusion coefficient Deft respectively range from 1. 798 4 ×10-8 to 3. 323 3 ×10-8 m2/s in different temperatures and range from 0. 579 3 ×10-8 to 2. 852 2 ×10-8 m2/s in different thicknesses. The effective diffusion coefficient increased with the increase of film thickness and air temperature; The Page model could properly describe the hot air drying behavior of papaya chips, the average value of R2, SSE, RMSE and X2 were 0. 998 1, 0. 003 3, 0. 012 4, 0. 000 2. By regression analysis, the expression of the relationship among the temperature, thickness and the effective moisture diffusion coefficient were achieved. The research results provided a reference to production practice for predicting air dried papaya moisture change.