Process and Antioxidant Activity of Flavonoid Extract from Abelmoschus esculentus

A microwave-assisted processes to extract flavonoids from Abelmoschus esculentus was optimized by a single factor and orthogonal experiment. By using 70% ethanol as the solvent, A. esculentus in a solid-liquid ratio of 1:40 (g·mL^-1)was extracted at 70℃ for 40 minutes. The yield of flavonoids was 2.78% with a relative standard deviation of 0.635%. The resulting extract was tested for its antioxidant activity by means of DPPH and ABTS radical scavenging capabilities to show IC₅₀at 1.21 mg·mL^-1 and 1.06 mg·mL^-1, respectively. It appeared that the current method could render a high yield on flavonoids that showed a substantial antioxidative activity.