Optimization of Extraction Process of Flavonoids from Bergamot and Its Antioxidative Activity in Vitro

In this study,flavonoids were extracted from Bergamot by ethanol extraction method. Based on the single factor experiments and the indexs of extraction rate,the response surface methodology was employed to optimize the extraction conditions of flavonoids from Bergamot and its antioxidant activity was evaluated. The results showed that the optimal extraction conditions of flavonoids from Bergamot were as follows:The ethanol concentration of 73%,extraction temperature of 80℃,extraction time of 90 min,solid-liquid ratio of 1:31 g/mL. Under these conditions,the yield of flavonoids was 1.34%. The results of antioxidation experiments showed that flavonoids of Bergamot had certain clearance effect on scavenging DPPH and ABTS free radical,and showed obvious dose-effect relationship,and the scavenging effect on DPPH radical and ABTS with IC₅₀ of 0.8 mg/mL and 0.07 mg/mL respectively. And the ORAC(total antioxidant capacity)was 20.18 μmol TE/g. The above results indicated that flavonoids from Bergamot were a good natural contioxidant.