豆薯籽油的超临界CO_2萃取及其理化特性

Supercritical CO_2 extraction and physicochemical properties of jicama seed oil

采用单因素实验和正交实验，以油脂萃取效率为评价指标，对超临界CO2萃取豆薯籽油的工艺条件进行了优化，利用GC～MS分析了油脂的脂肪酸组成，并检测了油脂的理化指标。结果表明，豆薯籽的平均含油量为28．43％，超临界CO2萃取的优化工艺条件为：萃取压力35MPa，萃取温度45℃，分离温度40℃，萃取时间90min，CO2流量25～30kg／h，原料粉碎度40目，原料含水量控制在5％左右。在此条件下，油脂萃取得率为25．91％，油脂萃取效率在91％以上。豆薯籽油的脂肪酸组分主要有油酸、亚油酸、棕榈酸、硬脂酸等，其中不饱和脂肪酸以油酸（31．20％）和亚油酸（29．26％）为主；理化特性与常见食用油脂相似，具有一定的开发利用价值。

The conditions for supercritical CO2 extraction of jicama seed oil were studied by single factor and orthogonal experiments according to oil extraction efficiency. Fatty acid compositions of the oil were identified by GC - MS. The physicochemical indexes of the oil were also analyzed. The results indicated that the oil content in jicama seed was 28.43%, and the optimum extraction conditions were as follows： extraction pressure 35 MPa, extraction temperature 45 ℃, separation temperature 40 ℃, extraction time 90 min, CO2 flow rate 25 -30 kg/h, material particle size 40 mesh and its moisture content about 5%. Under the conditions, the oil yield was 25.91%, and the extraction efficiency was beyond 91%. The main fatty acids of the oil were oleie acid, linoleic acid, palmitic acid and stearic acid. The unsaturated fatty acids were mainly composed of oleic acid （ 31.20% ） and linoleic acid （29.26%）. Meanwhile, the physicochemical characteristic of the oil was similar to common edible oil.