To optimize ultrasound-assisted extraction process of oil from peony seed cake, seven factors(particle size, ratio of liquid to solid, extraction time, extraction temperature, ultrasonic temperature, ultrasonic time and ultrasonic power)affecting the extraction of oil from peony seed cake were screened by Plackett-Burman(PB) design based on single factor experiment. By analyzing PB experimental result, particle size, extraction temperature, ratio of liquid to solid and ultrasonic temperature were selected as the factors.Then the extraction conditions of oil from peony seed cake were optimized by BBD response surface methodology as follows: particle size 80 meshes, ratio of liquid to solid 27∶?1, extraction time 4 h, extraction temperature 45?℃, ultrasonic temperature 42?℃, ultrasonic time 35 min and ultrasonic power 320 W. Under these conditions, the yield of peony seed oil was 11.15%. |