Optimization of Extraction Technology of Total Flavonoids from Rosa Chinensis Leaves by Response Surface Method

The extraction process of total flavonoids from Rosa chinensis leaves was optimized in order to provide technical references for the development and utilization of Rosa chinensis leaves. The effect of extraction times,liquid-solid ratio,extraction temperature,ethanol concentration and extraction time on the yield of total flavonoids from Rosa chinensis leaves were investigated using single-factor test. Based on the single-factor experiment results,response surface analysis methodology was employed to optimize the extraction process of total flavonoids. A mathematical model was established to evaluate factors influencing on extraction yield by central composite design (CCD). The results showed that the factors affecting yield of total flavonoids were in the order of:extraction temperature,extraction time,liquid-solid ratio and ethanol concentration. The optimal conditions for total flavonoids extraction were as follows:extraction temperature 66℃,extraction time 1.8 h,liquid-solid ratio 23:1 and ethanol concentration 61%,and the yield of total flavonoids was up to 12.84 mg/g under these conditions. Comparing six groups of experimental results with the predicted results of mathematical models found that the deviation between the two results was less than 5%,indicating that the established mathematical model was reliable and could be used to optimize the extraction process of total flavonoids from Rosa chinensis leaves.