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 pressureextraction temperatureextraction 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.