Reduction of Nicotine in Upper Leaves by Supercritical CO₂ Fluid Extraction

For improving the usability of upper leaves, tobacco was extracted with supercritical CO₂ fluid using 10%(v/v) of 95% ethanol as an entrainer.The tobacco leaves were chemically analyzed and(evaluated) by panelists before and after extracting.The results showed that: 1) under the extracting conditions of 18MPa, 45℃ and 30MPa, 60℃, the nicotine content in tobacco leaves reduced by 15.08% and 39.04%, respectively;2) the effect of extracting on the total sugar, reducing sugar, total nitrogen, chlorine and protein in tobacco leaves was relatively less significant;3) the smoothness and mildness of tobacco smoke were enhanced, offensive taste, strength and irritation reduced, and aftertaste was(improved) by supercritical CO₂ fluid extraction, while flavor concentration was not affected significantly.It was concluded that the smoking quality of upper leaves could be effectively improved by selective reduction of nicotine in tobacco to a desired level with supercritical CO₂ fluid extraction under proper conditions.