Abstract:The present study aimed to optimize the extraction conditions of polyphenols and polysaccharides from Physalis alkekengi fruit using aqueous two-phase ultrasonic-assisted methodology and evaluate the antioxidant activity of the extract.Ultrasound was used to assist C2H5OH-K2HPO4aqueous two-phase extraction of polyphenols and polysaccharides from P.alkekengi fruit.The extraction rates were used as indicators.The crude extraction process was optimized using a single factor design orthogonal experiment.To evaluate the antioxidant activity of polyphenols and polysaccharides from P.alkekengi fruit，the 1，1-diphenyl-2-trinitrophenylhydrazine（DPPH）and ferric reducing antioxidant power methods were applied.Under optimal extraction conditions for polyphenols，an aqueous two-phase system was constructed with a temperature of 20 °C，material-to-liquid ratio of 1∶40（g/mL），C2H5OH mass fraction of 24%，and K2HPO4mass fraction of 20%.The extraction rate of P.alkekengi fruit polyphenols was 83.44%.For the extraction of polysaccharides，an aqueous two-phase system was constructed with a temperature of 55 °C，material-to-liquid ratio of 1∶40（g/mL），C2H5OH mass fraction of 18%，and K2HPO4mass fraction of 41%.The polysaccharide of P.alkekengi fruit extraction rate was 89.10%.The results of these antioxidant experiments showed that the ability of P.alkekengi fruit polyphenols to scavenge DPPH free radicals and reduce ferric ions were stronger than those of P.alkekengi fruit polysaccharides.Thus，polyphenols and polysaccharides from P.alkekengi fruit have certain antioxidant capacities.Therefore，optimizing the extraction method using the ultrasonic-assisted double water method is promising and feasible.