基于叶片保水力的烟叶烘烤水分干燥模型构建

【目的】研究不同烟区、品种及部位烟叶保水力与水分干燥模型参数的关系,为烟叶烘烤提供简易、精准的水分预测方法并为烟草精准烘烤提供理论依据。【方法】以江西和湖南烟区烤烟品种K326和云烟87不同部位烟叶为试验材料,采用称重法测定烟叶保水力,结合水分干燥原理及水分干燥模型对烘烤过程中烟叶水分变化进行拟合求解,并对烟叶保水力与模型参数进行回归分析。【结果】不同部位间烟叶保水力随烟叶部位的升高而增加,不同品种间K326保水力均大于云烟87;除湖南烟区K326上部叶保水力大于江西烟区外,不同烟区间江西烟区烟叶保水力均大于湖南烟区。不同烟区、品种及部位烟叶Wang and Singh模型拟合决定系数R~2均大于0.95,且模型干燥参数a与烟叶保水力呈正相关,与干燥参数b呈负相关。烟叶保水力与模型干燥参数a、b之间线性回归结果显示:烟叶保水力与模型参数a、b显著水平P均小于0.05,且线性拟合决定系数R2均大于0.95。【结论】常规烘烤过程中烟叶水分比变化符合Wang and Singh模型,且烟叶保水力与干燥模型参数a、b存在极显著相关,可依据烟叶保水力精准估算模型参数预测烟叶烘烤过程中水分变化。

Tobacco leaf moisture drying model during flue curing based on leaf water holding capacity

Objective]The relationship between moisture drying model parameters and water holding capacity of to-bacco leaves from different tobacco production areas,tobacco varieties,and stalk positions were studied in this experi-ment in order to provide a simple and easy method for moisture prediction during flue curing process and lay a foundation for precise flue curing.Method]Leaves at different stalk positions of flue-cured tobacco varieties K326 and Yunyan87 in Jiangxi and Hunan were used as test samples. Weighing method was used to measure the water holding capacity of different leaves,moisture content variation in tobacco leaves during curing was fitted combining moisture drying model principle and moisture drying model. Regression analysis was used to analyze water holding capacity of tobacco leaves and the model parameters.Result]Water holding capacity of leaves at different stalk positions increased with the rising of stalk poso-tions. Among different flue-cured tobacco varieties,water holding capacity of K326 was always higher than Yunyan 87. Water holding capacities of tobacco leaves from Jiangxi tobacco production area were always higher than those from Hunan tobacco production area,except that water holding capacity of K326 upper leaves in Hunan tobacco production ar-ea were higher than those from Jiangxi. Fitting determination coefficient R2 of Wang and Singh model were all bigger than 0.95 in different tobacco production areas,tobacco varieties and stalk positions. In the model,drying parameter a was positively correlated to water holding capacity of tobacco leaves,but it was negatively correlated with drying parameter b. The linear regression result between water holding capacity and model drying parameter a and b indicated that the signifi-cant level P of water holding capacity and model drying parameter a and b were smaller than 0.05,and linear fitting deter-mination coefficient(R2)were higher than 0.95.Conclusion]The change of tobacco leaf moisture ratio is in line with the Wang and Singh model during normal bulk curing process,and there is extreme significant correlation between water holding capacity of tobacco leaves and drying model parameter a and b. Therefore,changes of tobacco leaves moisture during flue curing process can be predicted by accurate prediction model for water holding capacity of tobacco leaves.