烤烟化学成分指标的灰色关联聚类分析

Analysis of Chemical Components in Flue-cured Tobacco Leaves Based on Grey Relational Degree Cluster Method

烤烟化学成分指标之间的关系密切而复杂。为简化化学成分指标,选取我国主要烟区272份烟叶样品,对14个常规化学成分指标进行了灰色关联聚类分析。结果表明:当聚类临界值为0.8时,14个常规化学成分指标可被聚为5类,总氮、糖碱比、氮碱比、氯、总挥发性酸可以分别作为每类的代表;当聚类临界值为0.7时,化学成分指标被聚为酸性和碱性两大类,代表性指标分别为糖碱比和氮碱比。与系统聚类相比较,灰色关联聚类更具有合理性。表5,参6。

There existed close and complicated relationship among chemical components in flue-cured tobacco leaves. To simplify chemical component parameters,272 samples from main tobacco-growing areas of China were selected as materials, and 14 common chemical components were analyzed by grey relational degree cluster. The results indicated that the 14 common chemical components could be classified into five groups when cluster critical value was fixed at the level of 0.8. Meantime, total nitrogen, ratio of total sugar to nicotine, ratio of total nitrogen to nicotine, chlorine and total volatile acids were determined as the representative parameters for each group. When cluster critical value was fixed at the level of 0.7, the chemical components could be classified into two groups, named acids group and alkaloid group with representative parameters of the ratio of total sugar to nicotine and ratio of total nitrogen to nicotine, respectively, Grey relational degree cluster analysis was more rational than hierarchical cluster analysis.