Methods of treating cut stem tobacco material

Abstract

A method of treating cut stem tobacco material by expanding the cut stem to provide a first expanded tobacco material having a fill value at least about 10% greater than the fill value of the untreated cut stem tobacco material, intermittently contacting the first expanded tobacco material with a heated surface to provide a second expanded tobacco material with a moisture content of from 0 to about 10% OV and a fill value at least 5% greater than the fill value of the first expanded tobacco material; and (c) adjusting the moisture content of the second expanded tobacco material from about 5% to about 30% OV to provide an expanded product, wherein the fill value of the expanded product is at least 50% greater than the fill value of the untreated cut stem tobacco material when measured at a normalized moisture content of 14.5% OV.

1 . An apparatus comprising:
 a heated surface provided to intermittently contact a first expanded cut stem tobacco material, and   an inlet for the introducing the first expanded cut stem tobacco material into contact with the heated surface;   wherein the first expanded cut stem tobacco material is agitated and in direct and continuous contact with the heated surface for a period of up to about 5 seconds to produce a second expanded cut stem tobacco material.   
     
     
         2 . The apparatus as claimed in  claim 1 , the second expanded cut stem tobacco material having a moisture content from 0 to about 10% OV and a fill value at least 5% greater than the fill value of the first expanded cut stem tobacco material when measured at a normalized moisture content of 14.5% OV. 
     
     
         3 . The apparatus as claimed in  claim 1 , wherein the heated surface has a temperature of from about 100° C. to about 300° C. prior to contact with the first expanded cut stem tobacco material. 
     
     
         4 . The apparatus as claimed in  claim 3 , wherein the heated surface has a temperature of from about 120° C. to about 250° C., or from about 150° C. to about 300° C. prior to contact with the first expanded cut stem tobacco material. 
     
     
         5 . The apparatus as claimed in  claim 1 , wherein contacting the first expanded cut stem tobacco material with the heated surface heats the tobacco material to a peak temperature of from about 120° C. to about 230° C. 
     
     
         6 . The apparatus as claimed in  claim 1 , wherein the second expanded cut stem tobacco material has a moisture content of from about 1% to about 5% OV, or of no greater than about 2% OV following the intermittent contact with the heated surface. 
     
     
         7 . The apparatus as claimed in  claim 1 , wherein the first expanded cut stem tobacco material is intermittently contacted with a heated surface for a period of from at least about 1 minute to about 15 minutes. 
     
     
         8 . The apparatus as claimed in  claim 7 , wherein the first expanded cut stem tobacco material is intermittently contacted with a heated surface for a period of from at least about 2 minutes to about 10 minutes, or for a period of from at least about two and a half minutes to about 5 minutes. 
     
     
         9 . An apparatus as claimed in  claim 1 , comprising a treatment chamber including the heated surface and at least one mechanism for agitating the first expanded cut stem tobacco material selected from the group consisting of: a screw mechanism; a dual screw mechanism; air flow; and a rotating drum. 
     
     
         10 . An apparatus as claimed in  claim 1 , comprising a heated screw mechanism comprising a heated helical surface encircling a shaft which is rotated, the helical surface being configured to scoop up and lift at least a portion of the tobacco material being treated as the screw mechanism rotates, to carry the tobacco material and then to allow it to fall away from the screw. 
     
     
         11 . The apparatus as claimed in  claim 1 , further comprising a module for expanding a cut stem tobacco material to produce the first expanded cut stem tobacco material having a fill value at least about 10% greater than the fill value of the untreated cut stem tobacco material when measured at a normalised moisture content of 14.5% oven volatiles (OV). 
     
     
         12 . An apparatus as claimed in  claim 11 , wherein said module comprises any conventional expansion technology, optionally selected from the group consisting of: an expansion steaming tunnel, an STS (Steam Treated Stem) system, conditioning cylinder, a conditioning screw, or a pressurized conditioning screw. 
     
     
         13 . An apparatus as claimed in  claim 11 , wherein the module comprises any conventional drying technology, optionally selected from the group consisting of: a fluidised bed dryer, a flash tower dryer, a rotary dryer and a band dryer. 
     
     
         14 . The apparatus as claimed in  claim 11 , wherein the cut stem tobacco material is exposed to an expansion agent to produce the first expanded cut stem tobacco material. 
     
     
         15 . The apparatus as claimed in  claim 14 , wherein the expansion agent is selected from the group consisting of: liquid carbon dioxide, solid carbon dioxide, steam, liquid nitrogen, liquid short (C 5  or C 6 ) chain carbohydrates, or mixtures thereof. 
     
     
         16 . The apparatus as claimed in  claim 1 , further comprising a module for adjusting the moisture content of the second expanded cut stem tobacco material from about 10% to about 20% OV to provide an expanded cut stem tobacco product. 
     
     
         17 . The apparatus as claimed in  claim 16 , wherein at least one of water and steam is added to the second expanded cut stem tobacco material. 
     
     
         18 . The apparatus as claimed in  claim 16 , wherein the fill value of the expanded cut stem tobacco product is at least 5% greater than the fill value of the second expanded cut stem tobacco material when measured at a normalised moisture content of 14.5% OV. 
     
     
         19 . An apparatus as claimed in  claim 16 , wherein the module for adjusting the moisture content of the second expanded cut stem tobacco material comprises one or more selected from the group consisting of: a reordering drum, a steaming tunnel, and a band conditioner. 
     
     
         20 . An expanded cut stem tobacco material having a fill value of from about 6.5 to about 12 ml/g when measured at a normalised moisture content of 14.5% OV. 
     
     
         21 . The expanded cut stem tobacco material as claimed in  claim 20 , having an enhanced flavour profile or improved organoleptic properties compared to the flavour profile of cut stem tobacco material which has not been treated or which has been treated using only conventional curing processes. 
     
     
         22 . The expanded cut stem tobacco material as claimed in  claim 20 , having reduced quantities of one or more of: amino acids, ammonia and sugars compared to the quantities in cut stem tobacco material which has not been treated or which has been treated using only conventional curing processes. 
     
     
         23 . The expanded cut stem tobacco material as claimed in  claim 22 , having a nicotine content that is more than 50% less than the nicotine content of cut stem tobacco material which has not been treated or which has been treated using only conventional curing processes. 
     
     
         24 . The expanded cut stem tobacco material as claimed in  claim 22 , having a total sugars content that is more than 80% less than the total sugars content of cut stem tobacco material which has not been treated or which has been treated using only conventional curing processes. 
     
     
         25 . The expanded cut stem tobacco material as claimed in  claim 22 , having an ammonia content that is more than 80% less than the ammonia content of cut stem tobacco material which has not been treated or which has been treated using only conventional curing processes. 
     
     
         26 . A tobacco industry product comprising the expanded cut stem tobacco material of  claim 20 . 
     
     
         27 . Use of the expanded cut stem tobacco material of  claim 20  for the manufacture of a tobacco industry product.