Process for reducing the level of harmful substances in tobacco leaves

Abstract

The process for reducing the level of harmful substances in tobacco leaves comprises the following steps: steeping the leaves in a water bath at a temperature of between 13° C. and 25° C. for between 4 and 12 hours, cooling the leaves to a temperature not higher than −35° C.; and gradually heating the leaves at an average rate of not more than 2.0° C./h up to a temperature of at least 35° C.

1 . Process for reducing the level of harmful substances in tobacco leaves, comprising the following steps: 
 steeping the said leaves in a water bath at a temperature of between 13° C. and 25° C. for between 4 and 12 hours,    cooling the said leaves to a temperature not higher than −35° C., and    gradually heating the said leaves at an average rate of not more than 2.0° C./h up to a temperature of at least 35° C.    
   
   
       2 . Process according to  claim 1 , in which the said leaves are steeped in a water bath at a temperature of between 14° C. and 16° C. for between 6 and 10 hours.  
   
   
       3 . Process according to  claim 1 , in which the said leaves are cooled to a temperature of between −35° C. and −40° C.  
   
   
       4 . Process according to  claim 1 , in which the said leaves are heated at an average rate of between 1.5 and 1.8° C./h.