| 摘要 |
<p>A tobacco-treatment process comprises mechanically expressing cell_sap from yellowed, substantially undried, tobacco-leaf material, impregnating the fibrous material remaining after the expression with said cellsap or with parts or components of said cell-sap or with cell-sap expressed from other yellowed, substantially undried, tobacco leaf material, and drying the sapimpregnated material. The tobacco leaf material may comprise leaves harvested in a fully developed and mature state. The leaves may be at least partly yellow when harvested. They may have been yellowed by the application of a yellowing agent to tobacco plants or yellowing may have been effected or completed by heaping or rack-hanging the harvested leaves in an enclosed atmosphere, suitably with a relative humidity of 70% or more and a temperature in the range of 20 to 40.degree.C. Ethylene gas may be introduced into the atmosphere to promote the yellowing. The tobacco leaf material may be cut before being subjected to cell-sap expression. The expression may be effected in at least two stages, suitably a first stage in which the mid ribs of the tobacco leaves are crushed and a second stage in which the cell-sap is expressed from the lamina portions of the leaves. Before the impregnation with cell-sap, the sap, or parts or components thereof, may be subjected to a fractionating process to reduce the content therein of one or more constituent compounds. Before the sap expression, an antioxidant may be added to the leaf material or an antioxidant may be added to the cell-sap or parts or components thereof. An enzyme may be added to the cell-sap or parts or components thereof.</p> |
