Chemical Composition and Physical Properties of Oil from Plai (Zingiber cassumunar Roxb.) Obtained by Hydro Distillation and Hexane Extraction

Abstract

This research studied essential oils of three native varieties of plai obtained by hexane extraction and hydro distillation and collected from Sa Kaco (S1), Chiang Mai (S2) and Prachuap Khiri Khan (S3) provinces in Thailand. The results showed that the yield of oil obtained from S1, S2 and S3 by hexane extraction was 0.983%, 0.900% and 0.857% (w/w), respectively, while by hydro distillation the yield was 1.137%, 1.262% and 1.373% (w/w), respectively. The chemical constituents of essential oils isolated by hexane extraction and hydro distillation were examined by gas chromatography-mass spectrometry (GC-MS). The results showed that essential oils in the plai rhizomes isolated by hexane extraction and by hydro distillation were rather similar in their major composition, but different in minor components. The plai oil obtained by hexane extraction contained mainly: sabinene (24.05-39.11%), γ-terpinene (6.68-7.74%), terpinen-4-ol (33.11-49.36%) and (E)-1-(3,4-dimethoxyphenyl) butadiene (DMPBD) (5.31-8.28%), whereas that obtained by hydro-distillation contained: sabinene (36.71-53.50%), γterpinene (5.27-7.25%), terpinen-4-ol (21.85-29.96%) and DMPBD (0.95-16.16%).