Principal Component Cluster Analysis of Volatile Aroma Components in Over-dried Cut Tobacco Produced in Start and Finish Stages of Drying Process

In order to investigate the variation of volatile aroma components in over-dried cut tobacco produced in start and finish stages of a drying process in a thin plate rotary dryer, concerning twenty-one volatile aroma components in over-dried cut tobacco of different moisture contents of a third class cigarette brand, twelve of the volatile components selected by principal component subset selection method were used for principal component analysis. Three principal components, which cumulatively contributed more than 88% of resolution were extracted and scored. The cluster analysis and sensory evaluation of over-dried cut tobacco were validated by measuring the differences between tobacco samples via Squared Euclidean Distance method. The results showed that: 1) Thirteen tobacco samples were clustered into two categories. 2) CategoryⅢ included samples with moisture content ranging from 9.00%-12.50%, their volatile aromacomponent contents and sensory quality were close to those of normal dried cut tobacco; the moisture contents of the samples in Category Ⅲ were less than 9.00%, their volatile aroma component contents and sensory quality changed significantly. The results validated the feasibility of clustering over-dried cut tobacco with different moisture contents into two categories according to their volatile aroma component contents.