Objective: To optimize extraction process of polysaccharides from Abelmoschus esculentus leaves by response surface methodology and investigate its in vitro antioxidant activity

in order to provide reference for developing A.esculentus leaves. Method: Based on single-factor experiments

three independent factors

namely ultrasonic power

extraction temperature and extraction time

were selected as affecting factors for Box-Behnken central composite experiment design. With the polysaccharide extraction rate as the response value

the response surface analysis method was applied to optimize the polysaccharide extraction technique of A.esculentus leaves. DPPH·and·OH scavenging assays were carried out to study in vitro antioxidant activity of polysaccharides from A.esculentus leaves. Result: The results showed that the optimum conditions for extracting polysaccharides from A.esculentus leaves were ultrasonic power at 160 W

extraction temperature at 54℃

extraction time of 91 min. Under these conditions

the extraction rate of polysaccharides was 4.81%

with a small deviation from the theoretical value. The half inhibiting concentrations (IC50) to DPPH·and·OH were 2.65

1.47 g·L-1 respectively. Conclusion: The optimized extraction technique is stable and feasible

with a high extraction rate. Polysaccharides from A.esculentus leaves have a better anti-oxidation activity

and provide reference for industrialized production of A.esculentus.