Improved method of producing a liquid tobacco extract

Abstract

A method of producing a liquid tobacco extract is provided, the method including the steps of: preparing a tobacco material; heating the tobacco material at an extraction temperature of between 100 degrees Celsius and 160 degrees Celsius for at least 15 minutes, the tobacco material being heated directly; collecting volatile compounds released from the tobacco material during the heating step; and forming a liquid tobacco extract including the collected volatile compounds, the tobacco material being microwave heated during at least one step of the method. A liquid tobacco extract produced by the method is also provided.

1 .- 15 . (canceled) 
     
     
         16 . A method of producing a liquid tobacco extract, the method comprising the steps of:
 preparing a tobacco material;   heating the tobacco material at an extraction temperature of between 100 degrees Celsius and 160 degrees Celsius for at least 15 minutes, wherein the tobacco material is heated directly;   collecting volatile compounds released from the tobacco material during the heating step; and   forming a liquid tobacco extract comprising the collected volatile compounds,   wherein the tobacco material is microwave heated during at least one step of the method.   
     
     
         17 . The method according to  claim 16 , wherein the step of preparing the tobacco material comprises pre-treating the tobacco material by microwave heating to bring about rupture of tobacco cells, prior to the heating step. 
     
     
         18 . The method according to  claim 17 , wherein the step of heating the tobacco material is carried out by conventional heating. 
     
     
         19 . The method according to  claim 16 , wherein the step of heating the tobacco material comprises microwave heating the tobacco material. 
     
     
         20 . The method according to  claim 19 , wherein the step of heating the tobacco material comprises heating the tobacco material by a combination of microwave heating and conventional heating. 
     
     
         21 . The method according to  claim 17 , wherein the tobacco material is heated in a flow of inert gas during at least one of the heating step and the pre-treating step. 
     
     
         22 . The method according to  claim 16 , wherein the tobacco material has a moisture content of at least  10  percent by weight at a start of the microwave heating. 
     
     
         23 . The method according to  claim 16 , further comprising the step of applying water to the tobacco material prior to the microwave heating step in order to increase a moisture content of the tobacco material to at least 10 percent by weight. 
     
     
         24 . The method according to  claim 16 , wherein the tobacco material is continuously circulated during the microwave heating. 
     
     
         25 . The method according to  claim 16 , wherein the tobacco material is heated at an extraction temperature of between 125 degrees Celsius and 160 degrees Celsius. 
     
     
         26 . The method according to  claim 16 , wherein the extraction temperature is selected to provide a liquid tobacco extract having a nicotine content of at least 0.2 percent by weight based on dry weight. 
     
     
         27 . The method according to  claim 17 , further comprising the step of subjecting the tobacco material to an alkali treatment prior to the heating step and prior to the pre-treating step. 
     
     
         28 . The method according to  claim 16 , further comprising the step of spraying atomised water onto the tobacco material during the heating step. 
     
     
         29 . The method according to  claim 16 , further comprising the step of drying or concentrating the collected volatile compounds. 
     
     
         30 . A liquid tobacco extract produced by the method of  claim 16 .