Changes in states and physical properties of tobacco leaves _during curing in different curing barns | 不同烤房烘烤过程中烟叶形态和物理特性的变化

Chinese. 在研究不同烤房烘烤过程中烟叶形态变化的基础上，探讨造成密集烤房烤后烟叶光滑、僵硬的原因，为优化密集烘烤工艺提供理论依据。以烟株中上部烟叶为试验材料，研究密集烤房与普通烤房烘烤过程中烟叶的形态变化，并比较烤后烟叶物理特性的差异。在密集烤房烘烤过程中，烟叶形态变化呈现出变黄期缓慢、定色期剧烈、干筋期又减缓的趋势；而在普通烤房烘烤过程中，烟叶形态变化相对平缓。密集烤房烤后烟叶各形态指标除上部烟叶纵向卷曲度外,烟叶纵向收缩率、横向收缩率、面积收缩率、厚度收缩率、横向卷曲度及中部烟叶纵向卷曲度均显著或极显著小于普通烤房的相应处理。与普通烤房相比，密集烤房烤后烟叶单叶质量、叶质重与叶片厚度较大，而含梗率、平衡含水率与拉力较小。密集烘烤条件下烟叶形态变化较小，并最终导致烟叶组织紧密及个别物理特性指标较差。

English. Based on study of states changes of flue-cured tobacco leaves during curing, reasons for slickness and stiffness of tobacco leaves cured in bulk curing barn were discussed to provide theoretical foundation to optimize bulk curing technology. Differences of states changes and physical properties of tobacco leaves cured in bulk curing barn and traditional flue-curing barn were studied，taking lumbar and upper leaves as experimental materials. States of tobacco leaves changed slowly in leaf-yellowing stage, rapidly in leaf-drying stage and slowly in stem-drying stage during bulk curing, but they were smoother in traditional flue-curing barn. States changing values such as vertical shrinkage, horizontal shrinkage, area shrinkage, thickness shrinkage, horizontal rolling index of tobacco leaves and vertical rolling index of lumbar leaves in bulk curing barn were significantly or extremely significantly smaller than that of corresponding treatment in traditional flue-curing barn expect vertical rolling index of upper leaves in the end. Single leaf weight, leaf density and thickness of tobacco leaves cured in bulk curing barn were bigger, whereas percentage of stem, balanced moisture content and tensile breaking strength were smaller than that cured in traditional flue-curing barn. States of tobacco leaves changed less during bulk curing, causing tight structure and some non-ideal physical properties of tobacco leaves.