采用响应曲面法对紫皮洋葱油提取工艺进行优化。以紫皮洋葱油得率为指标,采用索氏提取法,对提取溶剂,提取时间,料液比和回流温度等提取条件进行单因素试验。在此基础上,根据Box-Benhnken中心组合方法进行三因素三水平的试验设计,并进行响应面分析。结果表明,紫皮洋葱油最佳提取工艺条件为:石油醚为溶剂,料液比为3.64/80(g:mL),提取时间为3.83h,回流温度为78.49℃。在此工艺条件下,紫皮洋葱油得率理论值为0.462%,实测值为0.470%,与理论值相比,相对误差为1.73%。

Response surface methodology was used to optimize the extraction conditions of onion oil from purple Allium cepa L.The yield of purple onion oil was the index,extraction solvent,extraction time,ratio of solid to solvent and reflux temperature were studied as factors by Soxhlet extraction method.Based on the single factor experiments,a three-factor-three-level experiment design has been developed by Box-Benhnken central composite design method.The response surface method was applied to analyze the results of experiments.The results showed that the optimum extracting conditions for purple onion oil were as follows:solvent was petroleum ether,the ratio of solid to solvent was 3.64/80 g∶mL,extraction time was 3.83h and reflux temperature was 78.49℃.Under these conditions the predictive maximum yield of purple onion oil was 0.462%,the actual yield was 0.470%.the relative error was 1.73%.