Evaluation of Aroma in Oriental Tobaccos as Based On Valeric Acid Gas Chromatography

Levels of valeric acids (isovaleric and 3-methylvaleric) in leaves and smoke of different tobacco types were quantified by capillary gas chromatography (GC) using flame ionization detector (FID). The aroma characteristics of the smoke were scored by sensory evaluation. It was found that leaves of Oriental and burley tobaccos contain higher amounts of both valeric acid derivatives than Virginia tobaccos containing isovaleric acid but no 3-methylvaleric acid. Strong correlation between the aroma and pleasantness scores of smoke and the content of valeric acids in the leaves of Oriental tobaccos was observed, while it was not the case for leaves of Virginia and burley tobaccos. In all tobacco types no correlation between smoking characteristics and the content of valeric acids in the smoke was established. Regression models involving leaf isovaleric acid were developed that can be used to evaluate aroma and pleasantness of smoke in Oriental tobaccos. The data obtained allow the following conclusions to be drawn: a) 3-methylvaleric acid may be a chemical marker to distinguish Virginia tobaccos from Oriental and burley tobaccos; b) isovaleric acid content in leaves of Oriental tobaccos may be used for objective aroma evaluation that can be exploited for breeding and market purposes.