Extraction on green onions oil using simultaneous distillation and solvent extraction(SDE) and technology optimization

Green onions oil was extracted by Simultaneous Distillation and Solvent Extraction(SDE) method from green onions,and analyzed by GC/MS,25 peaks were separated and identified,which contents 13 sulfur-containing compounds,such as allyl methyl sulfide,methyl thiosulfinates,propyl methyl ester thiosulfate sulfur,trans allyl propyl three sulfur ether. 3 aldehydes:2-methyl-2-pentenal,2-butyne diethyl acetal,3-butyn diethyl acetal. 6 esters:such as 2-butenoate,3-pentenoic acid 4-methyl-methacrylate,2-butenoic acid vinyl ester.2 acidics,vinyl butyrate,2-methyl enanthate. 1 alcohol,2,4-dimethyl-3-pentanol. Four extraction parameters including distil- off temperature, ratio of liquid to material, extracting time, bath temperature were optimized using orthogonal design based on single factor investigations for the extraction yield of sulfur- containing compounds. And optimum extraction condition for distil-off temperature 95 ℃,ratio of material to liquid 1 ∶2(g∶m L),extracting time 3.5h,bath temperature 55℃. Under these conditions,the average content of sulfurcontaining compounds was 25.15mg/g.