Optimization of Extraction Process of Total Phenolic Acids from Lonicera confusa and Its Antioxidant Activity

The microwave-assisted extraction of total phenolic acid from Lonicera confusa was studied. Based on the single factor experiment and box-behnken response surface design,the effects of ethanol concentration,liquid-material ratio,extraction temperature,extraction time and microwave power on the yield of total phenolic acid were discussed,and the optimal extraction conditions of total phenolic acid from Lonicera confusa were optimized. The antioxidant activity of total phenolic acid extract of Lonicera confusa was evaluated by DPPH radical scavenging assay and ferric ion reducing power assay. The results showed that the optimum extraction conditions were 80% ethanol concentration,12:1 mL/g liquid to material ratio,70℃ extraction temperature,30 min extraction time,400 W microwave power,the total phenolic acid content reached 59.45±0.13 mg/g,which was similar to the model prediction value of 57.76 mg/g. The IC₅₀ value of DPPH radical scavenging rate was 21.26 μg/mL,and the EC₅₀ value of ferric ion reducing power assay was 39.37 μg/mL. The results showed that the total phenolic acid extract of Lonicera confusa had good antioxidant activity,which provided theoretical basis for the development of Lonicera confusa.