Abstract:

The discarded tobacco extracted by supercritical CO₂ was separated by molecular distillation techniques and analyzed by GC-MS. Fifty-two kinds of compounds were identified in total. 15 kinds of compounds were identified by the 80 ℃ light fraction. Among them, heterocycles were dominant, accounting for 98.91% of the total, followed by esters(0.606%). Twenty-six kinds of compounds were identified by the 120 ℃ light fraction. The chemical classes were mainly made up of heterocycles(91.42%), with relatively small amounts of ketones(4.16%), alcohols(2.87%) and hydrocarbons(0.74%). There were 26 kinds of compounds identified by the 160 ℃ light fraction. Alcohols(67.97%) were the dominant chemicals, followed by heterocycles(11.57%), hydrocarbons(7.9%), ethers(4.09%), ketones(3.77%), esters(2.80%) and aldehydes(1.89%), respectively. There were obvious differences in the compound types and contents of different fractions, which reflected the selective enrichment feature of molecular distillation. The sensory evaluation of the mixture of the 80 ℃ and 120 ℃ light fraction with the mass ratio of 8:2 was better. The sample's aroma quantity and quality increased, the after taste got more comfortable. Meanwhile it presented sweet aroma and more pure smoke flavor.

Key words: molecular distillation, discarded tobacco, aroma constituents, sensory evolution