Method for producing flavorful and aromatic compounds from tobacco

Abstract

The invention provides a method of producing flavorful and aromatic compounds from tobacco by (1) adjusting the pH of an aqueous composition comprising water and a tobacco material to at least about 6 using a nitrogen-free base, such as an alkali metal hydroxide; and (2) heating the pH-adjusted aqueous composition for a time and under conditions sufficient to produce flavorful and aromatic compounds, such as pyrazines. A reducing sugar can be added to the aqueous tobacco composition to further increase the amount of flavorful and aromatic compounds produced. The tobacco material in the aqueous tobacco composition may comprise solid tobacco particles or an aqueous tobacco extract in either liquid form or in the form of spray-dried particles. The treated aqueous composition can be applied to a smokable material during the manufacture of a smoking article, such as a cigarette.

What is claimed:  
     
         1 . A method of producing flavorful and aromatic compounds from tobacco, comprising: 
 providing an aqueous tobacco composition comprising water and a tobacco material;    adding an amount of a nitrogen-free base to the aqueous composition sufficient to increase the pH of the aqueous composition to at least about 6; and    heating the aqueous composition for a time and under conditions sufficient to produce flavorful and aromatic compounds.    
     
     
         2 . The method of  claim 1 , wherein the tobacco material comprises solid pieces of whole tobacco.  
     
     
         3 . The method of  claim 2 , wherein the tobacco is in particulate form.  
     
     
         4 . The method of  claim 1 , wherein the tobacco material comprises at least one aqueous tobacco extract.  
     
     
         5 . The method of  claim 4 , wherein the at least one aqueous tobacco extract is selected from the group consisting of aqueous extracts of flue-cured tobacco, aqueous extracts of burley tobacco, aqueous extracts of Oriental tobacco, aqueous extracts of Maryland tobacco, and mixtures thereof.  
     
     
         6 . The method of  claim 1 , wherein the tobacco material is present at a concentration of about 5 to about 90 percent by weight based on the weight of the aqueous tobacco composition.  
     
     
         7 . The method of  claim 1 , wherein the tobacco material is present at a concentration of about 10 to about 80 percent by weight based on the weight of the aqueous tobacco composition.  
     
     
         8 . The method of  claim 1 , wherein the nitrogen-free base is selected from the group consisting of hydroxides of an alkali metal or an alkaline-earth metal, carbonates of an alkali metal or alkaline earth metal, and alkoxides of an alkali metal or alkaline earth metal.  
     
     
         9 . The method of  claim 1 , wherein the nitrogen-free base is sodium hydroxide or potassium hydroxide.  
     
     
         10 . The method of  claim 1 , wherein said adding step comprises adding sufficient nitrogen-free base to increase the pH to at least about 9.  
     
     
         11 . The method of  claim 1 , wherein said adding step comprises adding sufficient nitrogen-free base to increase the pH to at least about 10.  
     
     
         12 . The method of  claim 1 , wherein said adding step comprises adding sufficient nitrogen-free base to increase the pH to at least about 11.  
     
     
         13 . The method of  claim 1 , wherein said adding step comprises adding sufficient nitrogen-free base to increase the pH to about 8 to about 14.  
     
     
         14 . The method of  claim 1 , wherein said adding step comprises adding sufficient nitrogen-free base to increase the pH to about 9 to about 12.  
     
     
         15 . The method of  claim 1 , wherein the aqueous composition is heated at a temperature of about 25° C. to about 200° C.  
     
     
         16 . The method of  claim 1 , wherein the aqueous composition is heated at a temperature of about 80° C. to about 150° C.  
     
     
         17 . The method of  claim 1 , wherein the aqueous composition is heated at a temperature of about 95° C. to about 130° C.  
     
     
         18 . The method of  claim 1 , wherein the aqueous composition is heated for about 30 minutes to about 3 hours.  
     
     
         19 . The method of  claim 1 , wherein the aqueous composition is heated for about 30 minutes to about 1.5 hours.  
     
     
         20 . The method of  claim 1 , wherein said heating step is conducted in atmospheric air and under atmospheric pressure.  
     
     
         21 . The method of  claim 1 , wherein the aqueous composition further comprises a reducing sugar or a precursor or derivative thereof.  
     
     
         22 . The method of  claim 21 , wherein the reducing sugar is selected from the group consisting of glucose, fructose, sucrose, mannose, galactose, rhamnose, and mixtures thereof.  
     
     
         23 . The method of  claim 21 , wherein the concentration of the reducing sugar is about 1 to about 20 percent by weight based on the weight of the aqueous composition.  
     
     
         24 . The method of  claim 21 , wherein the concentration of the reducing sugar is about 2 to about 10 percent by weight based on the weight of the aqueous composition.  
     
     
         25 . The method of  claim 1 , further comprising applying the aqueous composition to a smokable material.  
     
     
         26 . The method of  claim 25 , wherein the smokable material is tobacco.  
     
     
         27 . The method of  claim 25 , wherein the aqueous composition is applied as a top dressing or casing.  
     
     
         28 . The method of  claim 1 , further comprising applying the aqueous composition to insoluble tobacco pulp to form a reconstituted tobacco material.  
     
     
         29 . A method of producing flavorful and aromatic compounds from tobacco, comprising: 
 providing an aqueous tobacco composition comprising water and a tobacco material, the tobacco material comprising solid pieces of whole tobacco or at least one aqueous tobacco extract;    adding an amount of a nitrogen-free base to the aqueous composition sufficient to increase the pH of the aqueous composition to at least about 9; and    heating the aqueous composition at a temperature of about 80° C. to about 150° C. for a time sufficient to produce flavorful and aromatic compounds.    
     
     
         30 . The method of  claim 29 , wherein the aqueous composition is heated at a temperature of about 95° C. to about 130° C.  
     
     
         31 . The method of  claim 29 , wherein the nitrogen-free base is selected from the group consisting of hydroxides of an alkali metal or an alkaline-earth metal, carbonates of an alkali metal or alkaline earth metal, and alkoxides of an alkali metal or alkaline earth metal.  
     
     
         32 . The method of  claim 29 , wherein the aqueous composition further comprises a reducing sugar or a precursor or derivative thereof.  
     
     
         33 . The method of  claim 32 , wherein the reducing sugar is selected from the group consisting of glucose, fructose, sucrose, mannose, galactose, rhamnose, and mixtures thereof.  
     
     
         34 . The method of  claim 29 , wherein said adding step comprises adding sufficient nitrogen-free base to increase the pH to at least about 10.  
     
     
         35 . The method of  claim 29 , wherein said adding step comprises adding sufficient nitrogen-free base to increase the pH to at least about 11.  
     
     
         36 . A method of producing flavorful and aromatic compounds from tobacco, comprising: 
 providing an aqueous tobacco composition comprising water, at least one reducing sugar, and a tobacco material, the tobacco material comprising solid pieces of whole tobacco or at least one aqueous tobacco extract;    adding an amount of a nitrogen-free base to the aqueous composition sufficient to increase the pH of the aqueous composition to at least about 9, the nitrogen-free base being a hydroxide of an alkali metal or an alkaline-earth metal; and    heating the aqueous composition for a time and under conditions sufficient to produce flavorful and aromatic compounds.    
     
     
         37 . The method of  claim 36 , wherein the aqueous composition is heated at a temperature of about 80° C. to about 150° C.  
     
     
         38 . The method of  claim 36 , wherein the reducing sugar is selected from the group consisting of glucose, fructose, sucrose, mannose, galactose, rhamnose, and mixtures thereof.  
     
     
         39 . The method of  claim 36 , wherein the reducing sugar comprises high fructose corn syrup.