Microwave-assisted extraction and antioxidant activity of star anise oil from Illicium verum Hook.f.

In this study, microwave-assisted extraction with ethanol (MAEE) of star anise oil from Illicium verum Hook.f. has been optimised by response surface methodology (RSM). A maximum yield of star anise oil was obtained at an optimum condition: the ratio of solvent to sample 17mLg(-1), extraction time 16min and microwave power 505W. Accordingly, the highest yield of star anise oil was about 24.98%, which was much higher than that of steam distillation (SD), 7.17%. Oxygenated organic compounds in representative of trans-anethole are a major component in star anise oil, nearly 94.21% for SD and 86.66% for MAEE, identified and determined by GC-MS. The oils extracted by SD and MAEE both have strong antioxidant activities that were demonstrated by the DPPH and ABTS assays.