Abstract:To improve the comprehensive utilization rate and reduce the waste of foxtail millet bran resources，ultrasound-assisted extraction was used for defatting of fresh foxtail millet bran with 95% ethanol as the defatting agent. On the basis of single factor experiments， the defatting process of foxtail millet bran was optimized by response surface method with defatting rate as the evaluation indicator. The results showed that the optimum combination of defatting conditions for foxtail millet bran was as follows： the solid-to-liquid ratio of 1∶17 （g/mL），ultrasonic time of 15 min， ultrasonic power of 600 W， and ultrasonic temperature of 55 ℃. Under these conditions， the defatting rate reached 95.32%， which showed the relative error of only 1.07% with the predicted value of 94.31%. After defatting， the content of fat in foxtail millet bran decreased from 13.37% to 0.63%，while the protein and dietary fiber were retained. Scanning electron microscopy results of foxtail millet bran showed that after defatting， the bran was not easy to aggregate， and the powder was more fine and uniform，which indicated that defatting improved the utilization value of foxtail millet bran.