Optimization process of ultrasonic-assisted extraction of puerarin from the stem of Pueraria lobata by response surface methodology

The purpose of the study is to optimize the ultrasonic-assisted extraction process of puerarin from the stem of Pueraria lobata. The extraction temperature, concentration of alcohol, ultrasonic time and ratio of liquid to solid were chosen as independent variables based on the single factor experiment, and the experimental program was arranged according to the principle of central composite design. The result was analyzed by response surface methodology. The results showed that the extraction temperature, concentration of alcohol and ultrasonic time had significant effect on the extraction yield of puerarin and the optimum conditions were determined as follows:extraction temperature 57℃, concentration of alcohol 69%, ultrasonic time 45 min, and ratio of liquid to solid 21 ∶1.Under these conditions, the predicted value and experimental value of the extraction yield of puerarin were 3.532%and 3.524%, respectively.