The invention discloses a preparation method of a high-
nicotine tobacco extract. The preparation method of the high-
nicotine tobacco extract belongs to the field of tobacco additives, and mainly comprises three steps of
raw material pretreatment, subcritical extraction and molecular
distillation. A baking process is adopted for pretreating tobacco leaves, so that
reducing sugar of tobacco and a
nitrogen-containing compound are promoted to generate
maillard reaction, substances such as
pyrone and furanone are produced, the baking
aroma is improved, the
reducing sugar content is reduced, the suction offensive
odor is reduced, meanwhile, combined-state
nicotine in the tobacco leaves is converted into a
free state, and the content of the free-state nicotine is improved. A weak polar
solvent is adopted for subcritical extraction, so that the extraction rate of tobacco feature
aroma substances and the free-state nicotine can be improved; and low-temperature molecular
distillation is combined, so that low-boiling-point
aroma substances and the nicotine can be effectively enriched, the damage on thermosensitive substances due to high temperature is avoided, and meanwhile, the content of
macromolecular substances such as
pectin and
protein in an extract is reduced. The method is simple in preparation process, simple and convenient to operate, and suitable for industrial production and application.