Abstract:

In order to investigate the differences and distribution patterns of chemical components and quality characteristics in different leaf positions of flue-cured tobacco leaves，this study took tobacco leaves as the test material， cut the leaves into 14 different zones from the tip to the base of the leaf， and tobacco strips were classified into five categories：large strip， medium strip， small strip， broken strip and fine dust，according to the size grade. Precise chemical composition analysis，cluster analysis，sensory quality evaluation were conducted on these samples. The results showed that the chemical component contents of flue-cured tobacco leaves varied greatly among different leaf positions and the size grade of tobacco strips，with obvious variation patterns from leaf tip to leaf base. The contents of total sugar and reducing sugar gradually decreased from the leaf margin to the main vein，while the contents of nicotine and total nitrogen were higher in the leaf tip and leaf margin，and potassium，chlorine and pigment contents were more enriched in the leaf base. Based on the overall chemical components，the leaves can be clustered into two major categories：zones 1-7，9，10，and large strip，medium strip，broken strip，fine dust，and small strip，as well as zones 8 and 11-14. In practical production，tobacco leaves with similar clustering results can be substituted for one another，thereby alleviating the shortage of certain tobacco raw materials. The results of the study clarified the distribution patterns of chemical components in different positions of flue-cured tobacco leaves，and provided a theoretical basis for improving the refined processing of flue-cured tobacco and enhancing the utilization value of tobacco raw materials.

Key words: flue-cured tobacco leaf, different positions, chemical components, quality characteristics, differential analysis