Optimization of Extraction Process and Antioxidant Activity of Flavonoids from Viola yedoensis
This article used water extraction and alcohol extraction methods to extract total flavonoids from Viola yedoensis,and determined the flavonoid content and antioxidant activity in the extracted solution.In the water extraction method,the material to liquid ratio,water bath temperature,and water bath time were the factors to be considered.The experimental results showed that the ratio of Viola yedoensis to water was 1∶10,the optimal water extraction parameters were water bath temperature of 80 ℃,extraction time of 2.0 hours,and the yield of flavonoids was 9.96 mg/g.Ethanol concentration,solid-liquid ratio,and ultrasound time were considered factors in the alcohol extraction method.The experimental results showed that the optimal ethanol extraction parameters were ethanol concentration of 80% ,solid-liquid ratio of 1∶15,ultrasound for 50 minutes,and flavonoid yield of 21.90 mg/g.The antioxidant activity of the extract was determined,and the results showed that the hydroxyl radical scavenging rate in the water extraction method was 84.43% .The hydroxyl radical scavenging rate in the alcohol extraction method was 94.90% .