Optimization of Centrifugal Extraction Technology of Verbascoside by Box-Behnken Response Surface Methodology

OBJECTIVE To extract the extract of verbascoside by centrifugal extraction system. METHODS The effects of content of verbascoside in oil phase, flow rate, oil-water ratio, extraction times, rotation speed, pH on the extraction rate of verbascoside were studied by single factor experiment. Box-Behnken response surface design was used to explore the effects of the content of verbascoside in oil phase, flow rate, rotation speed, oil-water ratio on the extraction rate of verbascoside and optimize the optimal process parameters. RESULTS The results of single factor experiment showed that the optimum extraction conditions were as follows: the content of verbascoside in oil phase was 19.20 mg·mL^-1, the rotation speed was 48 Hz, the flow rate was 300 mL·min^-1, the ratio of oil phase to water phase was 1∶1, the amount of acetic acid was 2%, and the extraction times were 3 times. Through response surface analysis, it was found that the order of factors affecting the extraction rate of verbascoside was as follows: content of verbascoside in oil phase>oil/water phase ratio>flow rate>rotation speed. Under the optimum conditions, the content of verbascoside in oil phase was 21.50 mg·mL^-1, the rotating speed was 48 Hz, and the flow rate was 290 mL·min^-1, with oil/water ratio of 1∶1, the results of three parallel experiments showed that the extraction rates of verbascoside were 82.49%, 79.38% and 81.76%, respectively, and the relative errors compared with the predicted value of 80.03% were 3.07%, 0.81% and 2.16%, respectively. CONCLUSION This method can effectively purify verbascoside and provide theoretical basis for the development and utilization of verbascoside.