A novel approach for isolation of essential oil from fresh leaves of Magnolia sieboldii using microwave-assisted simultaneous distillation and extraction

In this study, a novel approach was developed to isolate essential oil from fresh leaves of Magnolia sieboldii using microwave-assisted simultaneous distillation and extraction (MSDE). Response surface methodology with a three-factor-three-level experimental design was carried out to optimize the significant parameters of MSDE and to evaluate their interactions, including liquid-solid ratio, microwave irradiation time and power, and satisfactory yield for essential oil (0.94 +/- 0.05%) was obtained. Diagnostics of model adequacy was performed by predicted versus actual, normal % probability and internally studentized residuals. The developed MSDE was compared with traditional SDE, HD and MHD methods, in terms of kinetics, chemical composition of essential oil, environmental impact and economic effect. The proposed method produced higher yield of essential oil in a shorter time and caused lower environmental impact and economic effect, in addition, essential oil produced by this method did not produce substantial change in its chemical composition through gas chromatography-mass spectrometry analysis. Main chemical compositions of the essential oil were beta-elemene and beta-phellandrene. Thus MSDE was developed successfully as a good alternative for preparation of essential oil from M. sieboldii as well as other herbs. (C) 2015 Elsevier B.V. All rights reserved.