| 摘要 |
Tobacco having at least about 6 percent moisture is impregnated with ammonia and carbon dioxide to introduce into the tobacco preferably from about 3 percent to about 6 percent by weight of ammonia and from about 3 percent to about 8 percent of carbon dioxide based on the weight of the tobacco. The impregnated tobacco is then heated for from about 5 to about 60 minutes at a temperature of from about 80 DEG to about 120 DEG C. in an open system to produce a tobacco product, having an OV of about 6% or less. The resulting tobacco product is, either with or without being bulked at room temperature, thereafter contacted with dry steam, preferably at low velocity, at a temperature which may be from about 100 DEG C. to about 150 DEG C., but is preferably from about 100 DEG C. to about 120 DEG C. for a time sufficient to puff the tobacco, preferably from about 1/4 to about 3 minutes. A humid gas, such as air of high humidity, may be used in place of the dry steam, in which case the temperature may be between about 80 DEG C. and about 150 DEG C. and is preferably from about 80 DEG C. to about 120 DEG C.
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