Based on the single factor analysis,the effect of liquid-solid ratio,ultrasonic power,extraction temperature,and extraction time on enhancing oil yield from Paeonia suffruticosa Andr.seed was evaluated by response surface analysis.A 4-factor,3-level Box-Behnken experimental design was applied and the interactions of each factor on the oil yield were also investigated.The optimal conditions were at 54℃ extraction temperature,11 mL/g liquid-solid ratio,300 W ultrasonic power,and 60 min extraction time using p...