基于初烤烟叶表面微观结构特征的叶片区段划分

Segmentation of flue-cured tobacco leaves based on their surface microstructure characteristics

为明确表面微观结构指标在烟叶分切中的应用效果,以云烟87的B2F和C3F初烤烟叶为试验材料,分别将2个部位的烟叶去除叶柄后垂直主脉平均分切成10个区段,利用扫描电镜和PHOTOSHOP软件量化分析了不同区段烟叶表面细胞面积、细胞周长、细胞形态因子、细胞密度、气孔密度和气孔指数,并采用回归分析法研究了两部位烟叶不同区段烟叶表面微观结构指标的变化趋势,通过Fisher最优分割法和感官评价分析了2个部位烟叶适宜的分段比例和感官品质差异。结果表明:①不同区段烟叶表面微观结构特征存在一定差异;从叶基到叶尖,细胞面积、细胞周长和细胞形态因子量化值呈先增大后减小的抛物线形变化趋势,细胞密度和气孔密度呈先降低后升高的抛物线形变化趋势,气孔指数总体呈线性增加趋势;B2F和C3F烟叶相同区段对比,细胞面积、细胞周长、气孔密度和气孔指数为B2F>C3F,细胞形态因子和细胞密度为C3F>B2F。②基于标准化的微观结构指标数据,利用Fisher最优分割法确定了云烟87的2个部位烟叶最优分割比例(叶基∶叶中∶叶尖)B2F为20%∶50%∶30%,C3F为30%∶50%∶20%。③感官评价结果表明,分切后各区段烟叶间的感官品质指标均存在显著差异,说明叶片表面微观结构特征指标结合Fisher最优分割法可将一片烟叶中品质差异较大的区段有效分开。

In order to study the effects of surface microstructure indexes on tobacco leaf segmentation,the B2F and C3F flue-cured tobacco leaves of cv.Yunyan 87 were equally divided into 10 sections longitudinally after removing the petioles.The cell areas,cell perimeters,cell morphological factors,cell densities,stomatal densities and stomatal indexes of the different sections were quantitatively analyzed with scanning electron microscope and PHOTOSHOP software.Regression analysis was conducted to study the changes of the surface microstructure indexes for the different sections of tobacco leaves from two stalk positions,and the optimal segmentation ratio and sensory quality differences of tobacco leaves from two stalk positions were analyzed by Fisher best division and sensory evaluation.The results showed that:1)The surface microstructure of the different segments of tobacco leaves were different.From the base to tip of the leaf,cell area,perimeter and morphological factors presented a parabolic trend that increased first and then decreased,while the cell density and stomatal density showed another parabolic trend that decreased first and then increased.The stomatal index increased linearly in general.When the same segment of B2F and C3F leaves were compared,cell area,cell circumference,stomatal density and stomatal index of B2F were higher than those of C3F,and cell morphological factor and cell density were reverse.2)Based on the data of standardized microstructure indexes,Fisher optimal segmentation method was used to determine the optimal segmentation ratios(base∶middle∶tip)for B2F and C3F tobacco leaves of Yunyan 87,and the ratio for B2F was 20%∶50%∶30%and that for C3F was 30%∶50%∶20%.3)The sensory results indicated that the overall sensory quality of the different segments of tobacco leaves differed significantly,which suggested that the surface microstructure of tobacco leaves combined with Fisher optimal segmentation method could effectively divide tobacco leaves into segments with great differences.