Abstract: Smoking articles comprising a high density, relatively low porosity coherent mass of combustible tobacco-containing material having at least one passage extending therethrough are disclosed. In a preferred embodiment the smoking article is a cylinder having at least one passage axially therethrough. The smoking article may further comprise a plug of ignitable material in passage blocking position at one end of the passage, said plug being such as to permit puff induced air flow therethrough. At least one additional plug may be similarly disposed at the opposite end of the passage or at an intermediate point in the passage. By adjusting the density, the surface area and/or the porosity of the mass available for combustion, the per puff delivery of tar by the smoking article upon combustion may be controlled.

Abstract: An improved process for expanding tobacco is disclosed wherein tobacco components such as stems, midribs and veins are contacted with an alkaline-hydrogen peroxide solution to effect expansion, washed and then dried and/or roasted to produce an expanded tobacco material highly suitable for use in smoking products. Prior to contact with the alkaline hydrogen peroxide solution, the tobacco materials are subjected to a pretreatment step with gaseous ozone to prevent clumping and/or interadherence of the tobacco shreds which would otherwise occur during the drying step.

Abstract: A method for increasing the filling power of sheet or shredded reconstituted tobacco which is normally not susceptible to conventional expansion techniques is provided. In the practice of the method reconstituted tobacco having a uniform moisture content of 15-50 weight percent is heated to a temperature above about 90.degree. C. for a period of time beyond that required to drive off substantially all moisture and then is reordered. Heating may be effected in a convection or microwave oven or a drying tower. By means of the method, the tobacco is stiffened whereby a substantially irreversible filling power increase is effected.

Abstract: Natural tobacco is extracted with water to produce a soluble extract and an insoluble fibrous residue. The aqueous extract is contacted by microorganisms, such as bacteria or fungi, capable of converting nitrate in the extract to nitrogen. Contacting may be done by adding a microorganism culture to a batch of the extract, or by passing the aqueous extract through a filter carrying a supply of the microorganisms. In either case, the contacting should take place in a substantially anaerobic environment. The culture may be produced by cycling a quantity of tobacco extract through a filtering medium to promote the growth of microorganisms occurring naturally in tobacco. Carbohydrate and/or protein is added to the denitrated extract to replace compounds depleted during the denitrating procedure. Ultimately, the denitrated extract is recombined with the fibrous tobacco residue.