Abstract:
Flavor compounds screening of cherry-red tobacco leaf and normal flue-cured tobacco leaf was performed to elucidate the chemical basis of the "glutinous rice flavor" of cherry-red tobacco leaf. One hundred and fourteen flavor compounds were detected and the average content of these compounds in cherry-red tobacco was 2.5 times of that of the control. There were 96 compounds with higher concentration in the cherry-red tobacco than the control, of which, 52 compounds with fold-change (cherry-red/control) more than 1.5 were identified. These compounds, mostly from the Maillard reaction and the decomposition of carotenoids, are very important contributors of the dominant flavor of tobacco. The results of this study were compared with published references and 21 common compounds were extracted. Collectively higher concentrations in cherry-red tobacco for 16 of the common compounds were discovered. The relationship between the level of the red color of the cherry-red tobacco and the concentration of the flavor compounds was also studied. The concentration of myosmine, 3-oxo-a-ionone, 2-hydroxymethyl-furan, 2-Cyclopentene-1,4 -dione, 2-methyltetrahydrofuran-3-one, nicotinaldehyde, and the unknown compound 18 were found to have the lowest concentration in the control and the highest concentration in the dark cherry-red, indicating that the concentration of these compounds maybe related to the color of the cherry-red tobacco. The elevated concentration of the detected flavor compounds may account for the basis of the "glutinous rice flavor".