Abstract:Pueraria lobata was taked as raw material to extract Pueraria lobata protein，the extraction rate of Pueraria lobata protein was used as the index to compare four different extraction processes.The Box-Behnken response surface design was used to optimize the extraction process of Pueraria lobate protein，and the antioxidant activity of Pueraria lobata protein in vitro was analyzed.The molecular weight of Pueraria lobate protein was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE）.The results showed that the best extraction technology of Pueraria lobate protein was as follows：extraction temperature 45℃，extraction time 2 hours，ratio of material to liquid 1∶20（g/mL），pH 3.5；the extraction rate of Pueraria lobate protein was 11.73%.Antioxidant experiment showed that Pueraria lobate protein had good scavenging effect of hydroxyl radical and DPPH radical，the scavenging rates were（88.62 ± 0.73）% and（51.15 ±0.32）% respectively，and the IC50of scavenging DPPH radical and hydroxyl radical were 0.78 mg/mL and 1.89 mg/mL，and had a certain reduction ability；SDS-PAGE results showed that Pueraria lobata protein bands were clear，and the molecular weight mainly distributed in 14.0 kDa-43.0 kDa.