Treatment of tobacco

Abstract

Methods of fermenting a tobacco material and methods of modifying the total bacterial content of a tobacco material are provided herein. One example method includes treating a tobacco material with superheated steam in a pressurized vessel to provide a steam-treated tobacco material having a reduced total bacteria content and fermenting the steam-treated tobacco material in the presence of one or more microorganisms to provide a fermented tobacco material. In some embodiments, the methods provided herein can provide a fermented tobacco material having a tobacco-specific nitrosamine content that is reduced relative to a fermented tobacco material that has not been subjected to the disclosed method steps and/or a modified flavor or aroma profile relative to a fermented tobacco material that has not been subjected to the disclosed method steps.

What is claimed: 
     
         1 . A method of preparing a fermented tobacco material, comprising:
 treating a tobacco material with superheated steam in a pressurized vessel to provide a steam-treated tobacco material having a reduced total bacteria content; and   fermenting the steam-treated tobacco material in the presence of one or more microorganisms to provide a fermented tobacco material.   
     
     
         2 . The method of  claim 1 , wherein the one or more microorganisms are present in exogenous amounts to the steam-treated tobacco material. 
     
     
         3 . The method of  claim 1 , wherein the fermented tobacco material has a tobacco-specific nitrosamine content that is reduced relative to a fermented tobacco material that has not been fermented in the presence of said microorganisms. 
     
     
         4 . The method of  claim 1 , wherein the fermented tobacco material has a modified flavor or aroma profile relative to a fermented tobacco material that has not been fermented in the presence of said microorganisms. 
     
     
         5 . The method of  claim 1 , wherein the one or more microorganisms do not facilitate conversion of nitrate to nitrite. 
     
     
         6 . The method of  claim 1 , wherein the one or more microorganisms are capable of growth competition with one or more nitrate-reducing microorganisms that are native to the tobacco. 
     
     
         7 . The method of  claim 1 , wherein the one or more microorganisms are nitrite sinks. 
     
     
         8 . The method of  claim 1 , wherein the one or more microorganisms comprise genes encoding for nitrite reductase. 
     
     
         9 . The method of  claim 1 , wherein the one or more microorganisms comprise bacteria. 
     
     
         10 . The method of  claim 1 , wherein the one or more microorganisms comprise  Tetragenococcus halophilus.    
     
     
         11 . The method of  claim 1 , wherein the one or more microorganisms comprise genetically modified bacteria. 
     
     
         12 . The method of  claim 11 , wherein the genetically modified bacteria comprise inserted genes encoding for nitrite reductase. 
     
     
         13 . The method of  claim 1 , wherein the tobacco-specific nitrosamine content is reduced by about 10% or more. 
     
     
         14 . The method of  claim 1 , wherein the tobacco-specific nitrosamine content is reduced by about 20% or more. 
     
     
         15 . The method of  claim 1 , wherein the tobacco-specific nitrosamine content is reduced by about 50% or more. 
     
     
         16 . The method of  claim 1 , wherein the tobacco-specific nitrosamine content of the fermented tobacco material is no more that the tobacco-specific nitrosamine content of the tobacco material. 
     
     
         17 . The method of  claim 1 , wherein the chloride content of the fermented tobacco material is between about 0.5% by weight and about 3% by weight. 
     
     
         18 . The method of  claim 1 , further comprising:
 processing the fermented tobacco material to provide a processed tobacco material in a form suitable for incorporation in a tobacco product; and   incorporating the processed tobacco material into an oral product.   
     
     
         19 . The method of  claim 19 , wherein the processed tobacco material is in the form of a tobacco blend. 
     
     
         20 . An oral product prepared according to the method of  claim 18 . 
     
     
         21 . The method of  claim 1 , wherein the treating step is conducted at a pressure in the range of about 5 psig to about 25 psig and a temperature in the range of about 100° C. to about 130° C. 
     
     
         22 . The method of  claim 1 , wherein the total bacteria content of the steam-treated tobacco material is reduced by about 95% or more. 
     
     
         23 . The method of  claim 22 , wherein the total bacteria content of the steam treated tobacco material is reduced by about 99% or more. 
     
     
         24 . The method of  claim 23 , wherein the total bacteria content of the steam-treated tobacco material is reduced by about 99.9% or more. 
     
     
         25 . The method of  claim 1 , wherein the stream-treated tobacco material exhibits the reduced total bacteria content after storage for at least 14 days post-treatment. 
     
     
         26 . The method of  claim 25 , wherein the steam-treated tobacco material exhibits the reduced total bacteria content after storage for at least 28 days post-treatment. 
     
     
         27 . The method of  claim 26 , wherein the steam-treated tobacco material exhibits the reduced total bacteria content after storage for at least 100 days post-treatment. 
     
     
         28 . A method of modifying the total bacteria content of a tobacco material, comprising:
 treating a tobacco material with superheated steam in a pressurized vessel to provide a steam-treated tobacco material having a reduced total bacteria content, wherein the treating is conducted at a pressure in the range of about 5 psig to about 25 psig and a temperature of about 100° C. to about 130° C.   
     
     
         29 . The method of  claim 28 , wherein the total bacteria content of the steam-treated tobacco material is reduced by about 95% or more. 
     
     
         30 . The method of  claim 29 , wherein the total bacteria content of the steam treated tobacco material is reduced by about 99% or more. 
     
     
         31 . The method of  claim 30 , wherein the total bacteria content of the steam-treated tobacco material is reduced by about 99.9% or more. 
     
     
         32 . The method of  claim 28 , wherein the stream-treated tobacco material exhibits the reduced total bacteria content after storage for at least 14 days post-treatment. 
     
     
         33 . The method of  claim 32 , wherein the steam-treated tobacco material exhibits the reduced total bacteria content after storage for at least 28 days post-treatment. 
     
     
         34 . The method of  claim 33 , wherein the steam-treated tobacco material exhibits the reduced total bacteria content after storage for at least 100 days post-treatment.