洋葱精油的多次精馏耦合提取及其GC-MS分析

采用多次精馏耦合提取新工艺提取了红皮洋葱精油，并用气相色谱质谱联用法结合计算机检索对红皮洋葱精油的化学成分进行分析和鉴定。结果表明：该工艺下可制得洋葱精油，得率为0.033 mL/kg。在洋葱精油中鉴定出14种化合物，占精油总量的70.2%。所制备的洋葱精油中主要物质为含硫化合物（w=62.1%），含硫化合物相对干物质的含量大于0.189 g/kg，此外还有少量的酮类和醛类化合物。对洋葱精油提取工艺的评价应从精油得率及其特征风味物质硫化物的含量两个方面考察。实验所用洋葱品种在单次精馏工艺下无法提取出洋葱精油，表明提取工艺及洋葱品种对二者有显著影响。

Multi rectification Coupling Extraction and GC-MS Analysis of Onion Essential Oils

A new technology of multi rectification coupling extraction was applied to prepare essential oils of red onion. The chemical components in the oils were separated and identified by gas chromatography mass spectrometry hyphenated method (GC MS) combined with computer search system. The yield of onion essential oils obtained by the new technology was 0.033 mL/kg. Fourteen compounds were determined, representing 70.2% of the total oil. Sulfides were the main flavor components in the prepared onion essential oils (w=62.1%). And the content of the sulfide compounds in the dry substances was higher than 0.189 g/kg. In addition, small amounts of ketone and aldehydes were found in the onion essential oils. The yield and content of sulfide compounds of onion essential oils are two factors which should be considered when a technology is evaluated. In this paper, essential oils in red onion can not be obtained by single rectification. The results showed that different onion varieties and extraction methods would significantly influence the yield and content of volatiles flavor co mponents of onion essential oils.