Effects of solvents and processes of extraction on the yield of coix seed oil.

The coix seed oil was extracted by combination of five kinds of solvents and three types of extraction methods. Among the five tested solvents,i.e. ethanol,ethyl acetate,acetone,dichloromethane,and cyclohexane,the acetone gave the highest recovery with refluxing extraction,ethanol gave the highest recovery with ultrasound-assisted extraction and microwave-assisted extraction. In addition,the oil content of the ultrasound-assisted extraction extract was found to be higher than that of the other two extraction methods. The microwave-assisted extraction was not suitable for the extraction of coix seed oil,although it took short extraction time.