Optimization of extraction conditions of total flavonoids from Zizyphus jujube by quadratic regression orthogonal rotating combination

In this study, zizyphus jujube was used as the raw material to investigate the clearance rate of DPPH·and the extraction rate of flavonoids by ultrasonic treatment. Effects of extraction temperature, extractant concentration, solid- liquid ratio, extraction time, enzyme dose, pH value, ultrasonic power on preparation of flavonoids with cellulase were studied by single factor analysis. The regression models were established with factors and the indexes, including extraction efficiency and DPPH· clearance rate.The results showed that the optimum values of temperature, extractant concentration, solid- liquid ratio, extraction time, enzyme dosage, pH and ultrasonic power were 45℃, 60%, 1∶25, 50min, 0.6%, 4 and 180W.Under this condition, the extraction efficiency was 0.537%, the DPPH·clearance rate was 40.2 %.