以新疆红肉苹果为试材,研究不同切片厚度、热风温度及热风速率下苹果切片的干燥特性,通过Origin 8.0软件对试验数据进行数学模型拟合,得到红肉苹果片的热风薄层干燥模型。结果表明,热风温度、切片厚度和热风风速对红肉苹果片的干燥特性均有一定影响,热风温度对其影响程度最为显著。热风温度越高,切片厚度越小,风速越大,红肉苹果片的干燥速率越大。综合而言,在热风温度80 ℃、切片厚度2 mm、热风速度1.5 m/s时,红肉苹果片干燥速率最大。所选6个数学模型均可以较好地阐述红肉苹果片在热风薄层干燥过程中的水分变化规律,其中Page模型具有最高的R2值、最低均方根误差RMSE及卡方值χ2,更适于评估红肉苹果片干燥过程中的水分脱除规律。
Based on the Xin-Jiang red-fleshed apple, the drying characteristics of apple slices were studied in terms of hot-air temperature, slice thickness and hot-air velocity. Origin 8.0 software was used to analyze data and optimize the mathematical model of red-fresh apple slices drying. The result showed that there factors affected the drying characteristics, and hot-air temperature had the greatest impact. Increasing hot-air temperature and hot-air velocity, or decreasing the thickness of slice, the drying rate(DR) of red-fleshed apple slices increased. When hot-air temperature was 80 ℃, the slice thickness was 2mm, hot-air velocity was 1.5 m/s, drying rate of red-fleshed apple slices was the highest. It was showed that all 6 drying models could describe the moisture changes of red-fleshed apple slices during hot-air and thin-layer drying. Page model had the highest R2, the lowest root mean square error (RMSE) and χ2. Therefore, it was the optimum model.