This paper studies the effect of different extraction procedures such as soxhlet extraction using n-hexane, distillation method and supercritical extraction (SFE) on the physicochemical properties of garlic essential oil. The yield of garlic essential oil by soxhlet extraction, steam distillation and SFE-CO2 methods was approximately 0.441, 0.124 and 0.465 %, respectively. The results of the oil analysis by gas chromatography/mass spectrometry method show the presence of five major compounds, including diallyl sulfide, diallyl disulfide, 3-vinyl-1,2-dithiacyclohex-4-ene, 3-vinyl-1,2-dithiacyclohex-5-ene and diallyl trisulfide. The antioxidant activity of the essential oil obtained by the SFE-CO2 method was significantly higher than by the distillation method, but was lower than the acid ascorbic one.
 Keywords
 Garlic essential oil, SFE, GC-MS, antioxidant activity, extraction.
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