Abstract: In order to optimize the extraction process of the Puerarin flavonoids,
Puerarin flavonoids yield was taken as an index, the quality score of solvent ethanol, extraction time,material-water ratio, extraction temperature,pH,extraction times, repeatability, recovery and reuse of solvent in the extraction process were studied. The results showed that the quality score of the ethanol was 70%, the extraction time was 120min, the material-water ratio was 1:10, the extraction temperature was 70℃, the pH was 5,the extraction times was 1; repeatability for extraction operation was good, recycling solvents was feasible and the solvent recovery was up to 94.3%. On this basis, the conditions of extracting Puerarin flavonoids were optimized using response surface mothod (RSM). Experimental factors and their levels were determined by one-factor tests.Subsequently, the Box-Benhnken experimental design with 3 factors and 3 levels was performed, and the factors influencing the technological were estimated by quadratic regression analysis with interaction terms. Response surface and contour were finally graphed with the extraction rate as the response value.The results showed that the optimal conditions of flavonoids extration were obtained as follows: the material-water ratio was 1:11, extraction temperature was 78℃，the quality score of solvent ethanol was 66 % and the extraction rate could be up to 2839.78μg/g.
Keywords: Puerarin Flavonoids; Extraction process; Solvent recovery;
Response surface method
