Effect of Distillation Time on Main Chemical Composition and Oil Yield of Eucalyptus citriodora Leaves

GU Yao;ZHOU Li-zhu;CHEN Jian-bo;LIANG Zhong-yun;LI Gui-zhen;DENG Zi-yu;MENG Zhong-lei;Guangxi Forestry Research Institute;School of Economics and Management,Beijing Forestry University;

citriodora oil;;citronellal;;distillation time;;steam consumption;;solid-liquid ratio

Distillation time was one of the important factors to affect the oil yield and main chemical composi-tions of Eucalyptus citriodora. The qualitative and quantitative analysis of different distillation time of volatileoil from 25-year-old E. citriodora were conducted by gas chromatography and gas chromatography-mass spec-trometry(CG-MS). Results showed that when the distillation time was 2.0 h,the oil yield(fresh leaves)was 1.220% and 42 compounds were identified. The main compounds which the relative content was more than1.000% were citronellal(58.188%),citronellol(12.959%),neoisopulegol(8.959%),citronellyl acetate(7.686%),p-menthane-3,8-diol(3.062%),1,8-cineole(1.665%),and isopulegol(1.005%).Those 6 compounds accounted for 93.524% of citriodora oils. GC results of volatile oil from 15-year-old E.citriodora indicated that when the steam consumption was 90 m L/min and the solid-liquid ratio was 1:1.8,theoil yield was 1.156% in 1.0 h. And the content of citronellal in volatile oil was 79.966%,the total content ofneoisopulegol and isopulegol was 9.313%. The characteristic components of the citriodora oil met the GB/T22179-2008 standard. The volatile oil became less with the extension of distillation time. It was suggested thatthe distillation time should be 1.0 h for the good quality of citriodora oil in order to reduce energy consumption and meet the national standard.