核桃油的超临界CO_2流体萃取及其脂肪酸成分分析

Extraction of Walnut Oil by Supercritical Carbon Dioxide Fluid and Analysis of Its Fatty Acid Components

采用超临界CO2流体萃取技术对核桃仁中核桃油的提取进行了研究。通过单因素试验,考察了萃取压力、温度、时间以及CO2流量对核桃油萃取率的影响。在单因素试验的基础上,用正交试验进行了工艺参数优化,其最佳萃取条件为:压力30 MPa、温度45℃、时间3 h、CO2流量4 L/min,在此条件下萃取率达到了50.1%。最后,通过气相色谱仪测定了核桃油的脂肪酸组成成分,结果表明,不饱和脂肪酸的质量分数92.2%,其中油酸、亚油酸和亚麻酸的质量分数分别为36.1%、14.2%和1.4%。

Walnut oil is extracted by Supercritical Carbon Dioxide Fluid（ SFE - CO2 ）. The effects of extraction pressure, temperature, time and CO2 flow of the extraction rate are investigated by the single factor test. On the basis of single factor test, the orthogonal test [ L9 （34） ] is used in optimization of technological parameters. The results of the experiments indicate that the optimum extraction pressure, temperature, time and CO2 flow for the maximum extraction is that： the pressure is 30 MPa;the temperature is 45 ~C ;the time is 3 h;and the CO2 flow is 4 L/min. And on this condition, the best extraction rate is 50.1%. Finally, the components of walnuts＇ fatty acid is determined by GC. The result shows that the mass fraction of unsaturated fatty acid is 92.2%. Among it, the oleic acid is 36.1% ;the linoleic acid is 14.2% ;and the linolenic acid is 1.4%.