Optimization of the Extraction Technology of Total Flavonoids from Edgeworthia chrysantha Lindl.by Response Surface Analysis and Its Antioxidant Activities in Vitro

The response surface method was used to optimize the extraction process of total flavonoids from Edgeworthia chrysantha Lindl and its antioxidant activity was evaluated. Based on single factor experiments,taking ethanol concentration,liquid to material ratio,extraction temperature and extraction time as optimization factors,the total flavonoid yield was an evaluation index,and the Box-Behnken method was used to optimize the extraction process of total flavonoids. The DPPH and ABTS free radical scavenging experiments were used to detect the antioxidant capacity of total flavonoids. The results showed that the optimal conditions were determined to be 80% for ethanol concentration,35:1 for liquid to material ratio,83℃for extraction temperature,85 min for extraction time,the total flavonoids yield was 22.76 mg·g^-1. The extract obtained under the optimal process conditions had a certain ability to scavenge free radicals,and had a significant concentration dependence on the total flavonoid content. The IC₅₀ values of scavenging DPPH radicals and ABTS radicals in vitro were 0.75 and 0.98 mg·mL^-1,respectively.