绞股蓝籽油脂的提取工艺研究及成分分析

通过单因素和正交试验对超声波辅助提取绞股蓝籽油脂的工艺条件进行优化，并对所得油脂进行成分分析。研究结果表明，超声提取采用石油醚为提取溶剂时，最佳油脂提取工艺条件为料液比1∶8（g∶mL），超声时间30 min，超声功率400 W，超声温度50 ℃。在此最佳工艺条件下，绞股蓝籽油脂提取率可达35.37%。所得绞股蓝籽油脂密度0.915 1 g/mL，酸值0.739 8 mg KOH/g，皂化值185.919 7 mg KOH/g，平均分子质量908.845 9 u，水分和挥发物含量0.281 9%。油脂中含有9种脂肪酸，其中6种为不饱和脂肪酸，占总脂肪酸含量的95%，含量最多的是α-桐酸（56.24%）。

Extraction technology and composition analysis of Gynostemma pentaphyllum seed oil

Ultrasonic-assisted extraction process of Gynostemma pentaphyllum seed oil was optimized by single factor test and orthogonal test, and the composition of the seed oil extract was analyzed. Using petroleum ether as extraction solvent, the optimal ultrasonic-assisted conditions were as follows: material to solution ratio 1∶8(g∶ml), extraction time 30 min, ultrasonic power 400 W and extraction temperature 50 ℃. Under the optimized condition, the extraction rate of seed oil could reach 35.37%. Physicochemical properties of the seed oil including density, acid value, saponification value, average molecular weight and the content of moisture and volatile matter were 0.915 1 g/ml, 0.739 8 mg KOH/g, 185.919 7 mg KOH/g, 908.845 9 u and 0.281 9%, respectively. GC-MS analysis revealed that there were 9 kinds of fatty acids in G. pentaphyllum seed oil, including 6 kinds of unsaturated fatty acids which accounted for 95% of the total fatty acids, and the major constituent was α-eleostearic acid (56.24%).