山苍子核仁油的提取及其化学成分分析

Extraction technology and chemical composition of Litsea cubeba kernel oil

由于山苍子核仁油的经济价值高,根据山苍子加工剩余物未得到充分利用的问题,优化了山苍子加工剩余物中核仁油的提取工艺,并分析其化学成分。采用石油醚（60~90℃）为溶剂回流提取山苍子核仁油,得到最优化工艺为原料粒径小于0.150 mm、提取温度80℃、料液比（m原料∶V石油醚）1∶14（g∶m L）、提取时间2.0 h下的核仁油得率26.69%。发现石油醚回流提取技术适用于山苍子核仁油的提取,具有产物得率高、色泽浅,且溶剂易于回收利用等优点。进一步运用气相色谱-质谱联用技术确定了山苍子核仁油的脂肪酸组成,共鉴定出8种脂肪酸,其中饱和脂肪酸4种,占脂肪酸总量的72.46%,不饱和脂肪酸4种,占脂肪酸总量的25.70%,脂肪酸中月桂酸的含量最高,可达49.53%。碳数居于10~12之间的中碳链脂肪酸占68.18%。化学成分分析表明山苍子核仁油是一种颇具开发潜力的天然油脂资源。

As a kind of featured aromatic plant resources,nearly 400 varieties of Litsea cubeba（ Lour.） Pers. distribute mainly in mountainous regions of South China such as Hunan,Fujian,Guizhou,Jiangxi Provinces,and so on. The fruits of Litsea cubeba contain essential oils which are usually used for the ionone synthesis. However,considering the content of essential oils is merely about 4%-8%,large amount of underutilized Litsea cubeba solid residues will be generated after extraction of essential oils,although they are enriched with natural oils,crude fiber,proteins and other micronutrient.On account of this,the conditions of extraction process and chemical composition of Litsea cubeba kernel oil were studied in this paper. The optimal extraction conditions by refluxing with petroleum ether（ 60-90 ℃） under orthogonal experimental design were obtained as follows： particle size of material less than 0.150 mm,material-solvent ratio at 1 ∶ 14（ g ∶m L）,extraction temperature of 80 ℃ and extraction time of 2.0 h. The maximum yield of the oil at 26.69% was obtained under the conditions mentioned above. The extraction technology of refluxing with petroleum ether was suitable for the extraction of Litsea cubeba kernel oil with advantages of high extraction rate,light of color,easy recovery and reuse of the extraction solvent,etc. Then the fatty acids composition of the kernel oil was determined by GC-MS technology. Eight kinds of fatty acids were identified from the fatty acids detection. Among the eight fatty acids,four kinds of saturated fatty acids made up 72.46% of the total fatty acids,respectively,capric acid（ 13. 69%）,lauric acid（ 49. 53%）,myristic acid（ 2. 48%） and palmitic acid（ 6. 76%）,in which the content of lauric acid accounted for the highest proportion. Other four kinds of unsaturated fatty acids accounted for 25.70% of the total fatty acids,respectively,caproleic acid（ 0. 58%）,lauroleic acid（ 4. 38%）,oleic acid（ 6. 90%） and linoleic acid（ 13. 84%）. The test results showed that,similar to virgin coconut oil,the main fatty acid compositions of Litsea cubeba kernel oil were medium-chain fatty acids. As a potential resource rich in natural oils,Litsea cubeba kernel oil can be used for the preparation of biodiesel,surfactant,and so on.