Isolation of tetra-acyl sucrose esters from turkish tobacco using supercritical fluid CO2 and comparison with conventional solvent extraction.

Pure supercritical CO2 at various pressures and temperatures was used to effect the fractionation of tetra-acyl sucrose esters (SE) from dried, ground Turkish tobacco without any further pretreatment of the matrix. It was determined that SE cannot be extracted using low density CO2 (150 atm, 60 degrees C, and 0.62 gm/mL or 200 atm, 100 degrees C, and 0.49 gm/mL), whereas other analytes, which strongly interfere with the conventional solvent extraction of SE, can be easily removed under the same conditions. At the higher temperature (100 degrees C), these same analytes that interfere with the conventional solvent extraction of SE are even more readily removed, while the very poor extractability of SE is not affected. It was demonstrated, however, that SE can be removed from the pre-extracted tobacco with supercritical CO2 if the density is greater than (or equal to) 0.73 gm/mL. The supercritical fluid extraction method has been compared with other previous extraction methods that employ conventional solvents. This study provides one of the clearest examples of how the variable density property of a supercritical fluid can be utilized to effect the fractionation of a complex mixture.