Abstract:The extraction of naringin from pomelo peel was optimized by using the technique of ultrasoundassisted extraction，and the antioxidant capacity in vitro of naringin extraction was analyzed and discussed.Selecting time，ultrasound-assisted power and solid-liquid ratio as the main parameters for single-factor experiment，response surface model to optimize the extraction conditions was adopted.The results showed that the optimum technical parameters was time of 71 min，ultrasonic power of 600 W，solid-liquid ratio of 1∶28（g/mL）.Under these conditions，the naringin extraction rate of was （3.8±0.4）%.In addition，it was found that the in vitro antioxidant capacity of naringin extraction with different concentrations had relatively ideal effects in different free radical systems.This experiment by the erythrocyte hemolysis was induced by 2，2'-azobis-2-methyl-propanimidamide（AAPH）model，and explored the naringin extraction antioxidant capacity at the cellular level.The results showed that erythrocyte hemolysis rate was （6.2±1.4）%compared with AAPH group reducing significantly，when naringin extraction was at the concentration of 5.35 μg/mL.It proved that naringin extraction can effectively protect the red blood cells from AAPH free radicals attack，thus significantly lower erythrocyte hemolysis rate under the oxidative stress.