超临界CO_2萃取青皮挥发油的工艺研究

采用正交实验法对超临界CO2萃取中药青皮挥发油的最佳工艺条件进行优选。以挥发油得率为考察指标,探讨了萃取压力、萃取温度、萃取时间三因素在不同水平下对青皮挥发油得率的影响,并与水蒸气蒸馏法进行了比较。研究表明,萃取压力对挥发油得率有显著影响,萃取温度及时间影响不显著,各因素作用主次关系为:压力>温度>时间。优选得到的最佳工艺为:萃取压力25 MPa,萃取温度35℃,萃取时间1.5 h,得率为1.3197%,比水蒸气蒸馏法提高2.4倍,时间减少78.57%。超临界CO2萃取收率高、耗时短、品质好。

Study on extraction process for volatile oil from Pericarpium Citri Reticulatae Viride by supercritical carbon dioxide

Orthogonal test of 3 factors at 3 levels was applied in optimization of supercritical CO2 extraction process for obtaining volatile oil from Pericarpium Citri Reticulatae Viride.The volatile oils were extracted by supercritical CO2 fluid under the different test conditions,i.e.different extraction pressure,different extraction temperature and different extraction time,with the extraction rate of volatile oil as index.The efficiency of supercritical CO2 extraction was compared with that of steam distillation.The results show that the effect of extraction pressure on the yield of volatile oil is significant,but extraction temperature and extraction time are not significant.The sequence according to the effect is as follows: extraction pressure>extraction temperature>extraction time.The optimum supercritical CO2 extraction conditions are determined as follows: extraction pressure 25 MPa,extraction temperature 35 ℃ and extraction time 1.5 h.The extraction rate of volatile oil obtained by supercritical CO2 extraction is 1.319 7%,which is 2.4 times higher than that from steam distillation,while the extraction time of supercritical CO2 decreases by 78.57%.Compared with traditional steam distillation,the supercritical CO2 extraction is featured by higher extraction rate,shorter extraction time and better quality,etc.