Abstract:
Response surface methodology (RSM) was applied in the optimization of process conditions for the extraction of phenolic compounds from pomegranate seed. On the basis of single-factor experiments, Box-Benhnken design involving four factors as independent variables was utilized to set up a quadratic polynomial regression equation for phenolic extraction yield as function of ethanol concentration, solid-liquid ratio, ultrasonic time, extraction temperature, and the respective variables and their influence on the yield were studied by using response surface analysis. The results showed that the optimal extraction conditions of polyphenol in pomegranate seeds assisted by the ultrasonic were: ethanol volume faction of 34%, the ratio of liquid-to-material 1∶24, ultrasonic time 31 min, extraction temperature of 51 ℃, ultrasonic power 180 W, ultrasonic frequency 80 kHz. The yield of polyphenols can be up to 7.73 mg/g under the optimal extraction condition, and the predictive value is only 1.69 % different.
