Abstract: Ultrasonic extraction and traditional reflux extraction of oil from Cucurbita moschata kernels were studied with orthogonal method. The influencing factors, including ratio of material to solvent, extraction time and ultrasonic power were researched in the experiment. The optimal conditions were obtained as follows: ratio of material to solvent 1∶15(w/v), extraction time 0.5 h and ultrasonic power 250 W, the yields of reflux extraction and optimum ultrasonic extraction were 49.9% and 50.8%, respectively. The oil composition was analyzed by GC-MS. The results indicated no obvious difference between two extracts, and the oil extracted by ultrasonic extraction had the lower acid value (1.51 mg·g^-1) compared to reflux method (3.25 mg·g^-1). The above results show that ultrasonic extraction is more convenient and time-saving, and the oil extracted by this method has the lower acid value.

Key words: Cucurbita moschata Kernels oil, ultrasonic extraction, GC-MS, acid value