Optimization of ultrasound and microwave assisted oil extraction from sea buckthorn seeds by response surface methodology

Sea buckthorn (SB) seeds were used as raw material to obtain SB oil using two extraction methods: ultrasound and microwave assisted extraction. The favorable experimental conditions that maximize the extraction efficiency were investigated by applying response surface methodology (RSM). The selected key independent variables were ultrasonic intensity (UI), temperature, and time for ultrasound assisted extraction (UAE) and microwave power, time, and solid/liquid ratio for microwave assisted extraction (MAE). The results obtained for extraction efficiency under optimal conditions are comparable for the two extraction methods (89.2 +/- 0.50% for MAE and 87.4 +/- 0.44% for UAE). The operation conditions for maximum extraction efficiency were: 13.77 W/cm(2) UI, 40 degrees C temperature, and 10 min extraction time for UAE and 225 W microwave power, 15 ml/g solid/liquid ratio, and 20 min extraction time for MAE. The extraction kinetics was characterized using a second order model for optimal conditions for UAE and MAE of SB seed oil.