红枣片热风干燥动力学研究

Study on the Hot-air Drying Dynamics of Red Jujube Slices

以新鲜骏枣为原料,研究了不同干制温度条件下枣片的干燥特性。选取了5种常用薄层干燥数学型,并采用非线性回归法进行拟合,从而建立枣片干燥数学模型。结果表明,枣片热风干燥过程中有明显的加速和减速阶段,在40℃-50℃内Page模型的拟合效果较好（决定系数R^2≥0.998）,枣片水分扩散系数在0.730 3×10^-7-1.095 3×10^-7范围内。经验证,该模型能很好地描述枣片热风恒温干燥过程水分比的变化规律,红枣片热风干燥Page模型的研究为预判干燥过程中红枣片水分含量和干制时间提供理论依据。

In order to explore the drying regularity of red jujube slices and provide a theoretical foundation for the drying of jujube slices, the drying characteristics of red jujube slices were evaluated in hot air dryer. Five commonly used thin-layer drying mathematical models were selected and used to fit the experimental data using non-linear regression analysis for establishing a suitable mathematical model that describes the drying of red jujube slices. The results indicated that the drying process involved two stages, acceleration phase and deceleration phase. Among these models, the Page model was the most suitable model for describing the drying curve of red jujube slices at 40 ℃- 60 ℃（R^2≥0.998）. The effective moisture diffusivity of red jujube slices was among 0.730 3×10^-7-1.095 3×10^-7. Therefore, the model could adequately describe the change regulation of water content according to the comparison of experimental values and predicted values.