Zonal distribution of neutral aroma components in flue-cured tobacco leaves

To understand the regional distributions of neutral aroma components (NACs) of interest in flue-cured tobacco (Nicotiana tabacum L.), samples from a single cured leaf lamina were taken at 48 distinct points with the help of a thin transparent plastic board. We investigated 28 NACs belonging to five categories, namely aromatic amino acid cleavage substances (ACS), cembratriendid alkyl degrading products (CADP), carotenoid degradation products (CDP), chlorophyll degradation products (CDPS), and Maillard reaction components (MRC), by comprehensive two-dimensional gas chromatography (GC x GC-TOFMS) analysis. Geostatistical tools and statistical software were subsequently used to analyze the NAC contents. The results showed that the contents of all the five categories had high levels of significance at 0.01. The nugget effect value of the different NACs exceeded 75%, and the Kriging interpolation map showed a continuous spatial structure. Based on the NAC contents, it was clear that only one principal component had a characteristic value greater than 1 (at 4.9), which accounted for 87.81% of the total variation. With the help of the Management Zone Analyst software, the NACs of a single tobacco leaf were accurately divided into six zones after k-means cluster verification. Overall, these results provide valuable information that will improve the use of tobacco leaves in tobacco threshing and redwing. Moreover, the results suggest the approach described herein can also be used for analyzing the distributions of chemicals in leaves with structures similar to tobacco.