【摘要】 以自2003年至2012年在国内外主要烤烟产地收集的5 170个烟叶样品的近红外光谱为试验对象,其中典型上部烟叶光谱1 394条,中部2 550条,下部1 226条;应用基于主成分及Fisher准则(PPF)的方法建立投影分析模型,遵循相邻主成分数下得到的投影结果没有显著性差异和主成分个数尽量少的原则,推荐主成分数为4下建立投影分析模型,模型结果表明:上、下部烟叶的近红外光谱特征具有显著差别,基本实现完全区分;而中部烟叶分别与上部和下部具有一定程度重叠,这与部位本身具有连续性特征的实际情况相符合。同时,依据模型得到的预测样品投影值与模型中各类投影均值之间的欧氏距离,对预测样品给出最近和次近类别及描述部位特征程度的量化分值,并结合模型中各类投影值的离散度以及设定的阈值,将预测结果细化为典型上、上偏中、中偏上、典型中、中偏下、下偏中、典型下等7类或超模型范围样品;应用2012年在实际复烤生产加工中取得的不同部位、不同产地的34个烟叶样品验证了分析结果的合理性。该种分析方式,不仅可以实现预测样品的判别分析,而且可得到关于预测样品更丰富的属性特征信息,可对烟草工业企业实现原料的均值化加工和烟叶配方等提供指导。更多还原

【Abstract】 In this paper,total of 5 170flue-cured tobacco samples collected from 2003 to 2012in the domestic and foreign origin by Shanghai Tobacco Group Technical Center were tested by near infrared spectroscopy,including the typical upper leaves1 394,central 2 550,the lower part of 1 226.Using projection model of based on principal component and Fisher criterion(PPF),follow the projected results to get no statistically significant differences at adjacent principal components,and the number of principal components as little as possible,in this paper,four main components to build projection analysis model,the model results show that:the near-infrared spectral characteristics of the upper and lower leaves have a significant difference that can be achieved almost entirely distinguished;while the middle leaves with upper and lower have a certain degree of overlap,which is consistent to the actual situation of the continuity of tobacco leaf.At the same time,Euclidean distance between the predicted sample projection values and the mean projection values of each class in the model,a description is given for the prediction samples to quantify the extent of the site features,and its first and second close categories.Using the dispersion of projected values in model and the given threshold value,prediction results can be refined into typically upper,upper to central,central to upper,typical central,central to the lower,the lower to central,typically the lower,or super-model range.The model was validated by 34 tobacco samples obtained from the re-drying process in 2012 with different origins and parts.This kind of analysis methods,not only can achieve discriminant analysis,and get richer feature attribute information,can provide guidance on the raw tobacco processing and formulations.更多还原