不同提取方法对杜仲籽油质量的影响

本文旨在研究索氏提取法、亚临界萃取法、超临界CO₂萃取法对杜仲籽油得率、主要理化指标及脂肪酸组成的影响。结果表明:索氏提取法、亚临界萃取法和超临界CO₂萃取法提取杜仲籽油的油得率分别为34.47%、28.42%、18.68%。索氏提取法得到的杜仲籽油过氧化值((0.087±0.002) g/100 g)和酸价((1.64±0.02) mg/g)最高,相对密度(0.87±0.01)和碘值((190.4±0.8) g/100 g)最低,提取的杜仲籽油品质最差;与索氏提取法相比,超临界CO₂萃取法和亚临界萃取法提取的杜仲籽油表现出较好的产品特性。不同方法提取的杜仲籽油的颜色有显著性差异(P<0.05),超临界CO₂萃取法提取的杜仲籽油亮度最高,颜色最好。气相色谱分析三种方法提取的杜仲籽油的主要脂肪酸种类基本相同,以油酸、亚油酸、α-亚麻酸为主,但各种脂肪酸的含量有所差异,其中不饱和脂肪酸含量为:超临界CO₂萃取法 > 索氏提取法 > 亚临界萃取法。经综合评价得出,超临界CO₂法萃取法提取的杜仲籽油品质较高,如果综合考虑成本因素和工业化操作方便程度,亚临界萃取法也是杜仲籽油提取的一种新型绿色工艺。本研究为杜仲籽油的开发和利用奠定了理论基础。

Effects of Different Extraction Methods on the Quality of Eucommia ulmoides Seed Oil

The aim of this study was to evaluate the effects of soxhlet extraction method(SE),subcritical extraction method(SBE)and supercritical CO₂(SC-CO₂)extraction method on the yield,main physical and chemical properties,as well as fatty acid composition of Eucommia ulmoides seed oil. The results showed that Eucommia ulmoides seed oil yield achieved by SE,SBE and SC-CO₂ were 34.47%,28.42% and 18.68%,respectively. SE showed the highest peroxide value((0.087±0.002) g/100 g)and acid value((1.64±0.02) mg/g),but the lowest relative density(0.87±0.01)and iodine value((190.4±0.8) g/100 g),which demonstrated that the quality was the worst. Compared with SE,the Eucommia ulmoides seed oil extracted by the SBE and SC-CO₂ showed better product characteristics. Significant difference(P<0.05)in color analysis was observed among three kinds of methods.Eucommia ulmoides seed oil extracted by SC-CO₂displayed the highest brightness and color. Moreover,these oil samples had nearly identical fatty acid composition which was measured by gas chromatography,and the main fatty acid were oleic acid,linoleic acid and α-Linolenic acid,but the content of various fatty acids was different. In addition,the content of unsaturated fatty acids was SC-CO₂ > SE > SBE. In comprehensive consideration,SC-CO₂ could produce Eucommia ulmoides seed oil with the best quality,SBE was also a new green process for extracting Eucommia ulmoides seed oil if comprehensive consideration of cost factors and ease of industrial operation. This study laid the theoretical foundation for the development and utilization of Eucommia ulmoides seed oil.