山苍子挥发油超声波辅助提取工艺优化及其GC-MS分析

采用响应面法优化超声波辅助提取山苍子挥发油的工艺条件。在单因素实验的基础上,选择提取时间、液固比、超声时间为影响因素,应用Box-Behnken中心组合进行3因素3水平的实验设计,以山苍子挥发油得率作为响应值,进行响应面分析（RSM）。结果表明:超声波法提取山苍子挥发油的最佳提取条件为:提取时间3.4h、液固比18∶1（m L/g）、超声时间12min,验证值为5.33%。同时采用气相色谱-质谱法（GC-MS）对挥发油进行成分分析,从挥发油中共分离出25个色谱峰,鉴定出21个化合物,检出率为98.97%,萜类化合物15个,GC含量为83.50%,其中（Z）-柠檬醛、（E）-柠檬醛、柠檬醛,是山苍子果实的特征性香气成分。 

Optimization of the ultrasound assisted extraction of volatile oil from Litsea Cubeba and analysis by GC-MS

Response surface analysis methodology( RSM) was used for optimizing ultrasound-assisted extraction of volatile oil from Litsea Cubeba. Based on single-factor experiments,three independent variables including extracting time,solvent-solidratio and ultrasound time,were selected as affecting factors during extraction. The experiments were arranged according to Box-Behnken central composite experiment design. Response surface analysis method was applied to determine the effect of central composite experiment design. The results showed that the optimum ultrasound extraction conditions for volatile oil from Litsea Cubeba were as follow: extraction time3.4h,ratio of liquid to solid 18∶1( m L/g) and ultrasound time 12 min.While the actual extraction yield was 5.33%.The volatile oil was analyzed by GC-MS,25 peaks were separated and 21 compounds which accounted for 98.97% of GC were identified. The result showed,that among 21 compounds,15 compounds are terpines. Among all of the chemical constituents of volatile oil from Litsea Cubeba,three isomers of Citral( z)-3,7-Dimethylocta-2,6-octadiena,( E)-3,7-Dimethyl-2,6-octadienal and 3,7-Dimethyl-2,6-octadiena were the characteristic aroma constituent for fruits of Litsea Cubeba.