The Reducing Property of Tobacco Smoke: 1. Modified FIue-Cured Tobacco and Other Smoking Products

In order to determine which tobacco constituents give rise to reducing compounds in smoke as well as to find out what factors affected the reducing property of the latter, modifications of flue-cured tobacco by solvent extraction and chemical impregnations were carried out. While no unequivocal evidence has been obtained as to the main source of reducing activity, all the evidence suggests that lignin and phenolic compounds derived therefrom, are the main contributors to reducing activity. A number of cigarette parameters, strand width, expansion of tobacco, paper porosity and burn control additives were studied and found to have no significant effect, within the Iimits tested, on the reducing power of the smoke. On the other hand, additives such as glycerol, ethylene glycol, polyethylene glycol, polypropylene glycol and carbowax gave distinctly lower reducing activities. Examination of tobacco products showed Iower reducing activities in smoke from Cuban, Latakia and Turkish tobaccos, as well as in smoke from cigarettes made from Indian sun-cured and French dark, fermented tobaccos. The lowest reducing activity was recorded for the highly fermented Perique tobacco. Indian ''bidis'' have specific reducing activities similar to those of standard flue-cured cigarettes. Freshly harvested, rapidly dried green tobacco as well as dried beech leaves, gave specific reducing activities close to those obtained for regular cigarettes. On the other hand, commercially available lettuce cigarettes, which undergo a fermentation step in their manufacture, gave distinctly lower specific activity