Optimisation of Essential Oil Extraction of Lindera neesiana From Supercritical Carbon Dioxide Fluid and Comparison to Steam and Simultaneous Distillation Extraction

A study was performed on the fruits of Lindera neesiana (Wall. ex Nees) Kurz essential oil extracted by different methods; steam distillation (SD), simultaneous distillation extraction (SDE) and supercritical fluid extraction (SFE). The operating conditions tested achieved a maximum yield, 11.08% for supercritical CO₂ extraction, 1.03% for steam distillation and 2.53% for solvent distillation. The response surface methodology was used to optimise the experiment. The extractions using supercritical CO₂ were performed at different pressure 131, 140, 163, 185 and 194 bar and at temperatures 41°C to 49°C. The optimised condition for the experiment was the pressure of 162 bar and temperature of 42°C in order to get the maximum extraction yield of about 10.44% of L. neesiana oil. Total 33 compounds were identified in L. neesiana oil from the fruits by GCMS. The constituents of oil extracted by different methods were mostly similar qualitatively whereas the relative proportions of compounds identified were markedly different. In the SFE, the less volatile compounds such as myristicin, elemicin, geranic acid and caryophyllene oxide are predominant whereas, in the SDE and SD process, the high volatile compounds including sulcatone, citral, α-pinene and eucalyptol are principal compounds. This variation in chemical composition suggests diverse potential industrial applications for the essential oils extracted by different methods. The increment of extraction yields upto 11.08% from SFE is an impressive achievement in the plant business.