烤烟上部叶带茎烘烤水分状态及形态变化分析

目的]探讨带茎烘烤烟叶失水干燥特性,为优化烤烟烘烤工艺提供参考依据.方法]测定带茎烘烤过程烟叶叶片和主脉的水分含量、状态及形态收缩率,与不带茎烟叶进行比较,并将烟叶水分指标与形态指标进行相关性分析.结果]带茎烘烤烟叶的整叶、叶片及主脉水含率均高于不带茎烟叶;带茎烟叶水分迁移表现为茎秆中的自由水向主脉和叶片迁移,使带茎烟叶叶片和主脉自由水含量和所占比例均高于不带茎烟叶.干叶前带茎烟叶叶片厚度收缩率显著小于不带茎烟叶叶片(P<0.05,下同),干叶后带茎烟叶叶片厚度收缩率显著大于不带茎烟叶叶片;烘烤过程带茎烟叶主脉直径收缩率显著小于不带茎烟叶;烘烤过程烟叶叶片和主脉自由水含量与其水含率呈极显著正相关(P<0.01).结论]烟叶形态收缩与自由水含量及其水含率密切相关,可根据烟叶形态收缩判断烘烤过程烟叶水分含量和状态.

Analysis on variation of moisture state and shape of flue-cured tobacco upper leaves with stalk during curing

Objective] In the present study,dehydration drying characteristics of flue-cured tobacco leaves with stalk during curing were investigated to provide a theoretical basis for optimization of curing technology.Method] The variation of moisture content,state and shape shrinkage in tobacco leaves with stalks were determined during curing,and compared with those of tobacco leaves without stalks.In addition,the correlation between water index and shape index of tobacco leaves was analyzed.Result] Moisture content in leaf,blade and midrib of tobacco with stalk was higher than that of tobacco without stalk,the moisture transport characteristics of tobacco leaf with stalk during curing were as follows:free water in tobacco stalk transported to tobacco blade and tobacco midrib,which made free water content and proportion in blade and midrib of tobacco with stalk higher than those of tobacco leaves without stalk.Thickness shrinkage rate of tobacco blade with stalk was significantly smaller than that of tobacco blade without stalk before leaf drying (P＜0.05,the same below).However,thickness shrinkage rate of tobacco blade with stalk was significantly higher than that of tobacco blade without stalk after leaf drying.Diameter shrinkage rate of tobacco midrib with stalk was significantly smaller than tobacco midrib without stalk during curing.There was extremely significant positive correlation between free water content in tobacco blade and its moisture content rate,and between free water in tobacco midrib and its moisture content rate.Conclusion] Tobacco shape shrinkage is closely related to free water content and moisture content rate.Tobacco moisture content and state can be judged through tobacco shrinkage.