为明确带茎采收对烤后上部烟叶质量的影响,以‘云烟87’为试材,通过主成分分析(PCA)、偏最小二乘法判别分析(PLS-DA)和变量权重重要性排序(variable importance in projection,VIP)等多维数据分析方法,研究湖北省6个乡镇带茎采烤与逐叶采烤烤后烟外观质量、物理特性、化学成分、感官质量等的差异。结果表明,剔除偏离指标后PLS-DA模型R_(X)^(2)=0.578、R_(Y)^(2)=0.997、Q^(2)_(PLS-DA)=0.96,模型有效;对模型进行200次响应排序,R^(2)_(intercept)、Q^(2)_(intercept)截距分别为0.903、-0.0125,模型拟合较好;最终共筛选出VIP>1.0指标差异较大的变量,包括还原糖、总糖、感官质量和多种氨基酸含量等共27项,其中总糖、还原糖、感官权重总分、香气质、杂气、刺激性6项为正向作用,其余21种为负向作用。综上所述,带茎采烤有利于提高上部烟叶的总糖、还原糖和部分感官因素的含量,不利于总氮、氨基酸类物质含量的提高。
烤烟烘烤效果受到诸多因素的影响,为在众多的影响因素中识别出烤烟烘烤的关键性影响因素,采用模糊DEMATEL(Fuzzy of Decision Making Trial and Evaluation Laboratory)分析法对影响烤烟烘烤的5大类(烟叶生长环境、烘烤环境、烟叶属性、装烟状况以及烘烤人员素质)17个因素的原因度与中心度进行了分析。结果表明,影响烤烟烘烤的主要因素有光照、大气温度、降雨、干球温度与湿球温度,其中烟草大田生长期间的降雨量、光照与大气温度是影响烤烟烘烤效果的根本因素,对烤房内干球温度与湿球温度的控制是影响烤烟烘烤效果的直接因素,而干球温度对烤烟烘烤的影响最大。
CuItivars K326, Yunyan 87 and Guiyan 4 were used to investigate the curing characteristics and suitabIe harvest maturity of fresh fIue-cured tobacco Ieaves in Ankang tobacco growing areas. ResuIts indicated that the water Ioss of K326 was sIow,and the Ieaves were resistant to curing and reIative easiIy to cure. The water Ioss of Yunyan 87 and Guiyan 4 were quick, and the Ieaves with normal resistance to curing were reIative difficuIt to cure. For Guiyan 4, the shrinkage of CM1 maturity was the Iargest. For K326 and Yunyan 87, the shrinkages of CM2 maturity were the Iargest whiIe the shrinkage of CM1 maturity was the Iowest, but the difference did not reach statistical significance. The proportion of top-middIe-grade tobacco Ieaves and average price for K326 were the highest with XM2, CM2 and BM2 maturity, and for Yunyan 87 were XM1, CM3 and BM2 maturity. For K326, Ieaves with XM2, CM2 and BM2 maturity showed the balanced chemical components and the best smoking quality.
