Comparison of different extraction methods: steam distillation, simultaneous distillation and extraction and headspace co-distillation, used for the analysis of the volatile components in aged flue-cured tobacco leaves.

Steam distillation (SD), simultaneous distillation and extraction (SDE) and headspace co-distillation (HCD) were compared here for their effectiveness in the extraction of volatile compounds from tobacco. The different grades of aged flue-cured tobacco leaves extracted by the three methods respectively were analyzed using GC-MS. Mass spectra or authentic compounds were used to identify around 408 components in various volatile fractions. On the one hand, the qualitative comparison showed that more compounds were detected in HCD extract (391 components) than in SDE extract (377 components), and the approximately quantitative analysis showed that the total amount of volatile components in SDE extract (445.48 microg/g) was much more than that in HCD extract (315.72 microg/g). But on the other hand, HCD was the most efficient for nearly all the highly volatile compounds among the three methods. As to low-volatile compounds such as lactones, long chain aldehydes, ketones, alcohols, and esters, more was detected in SDE extract than in HCD extract. The SD method (322 components, total amount 228.42 microg/g) was the lowest sensitive to all compounds except semi-volatile fatty acids among the three methods.