Abstract: In order to maximize protein extraction from Ginkgo biloba L. seeds with NaOH solution, a mixed-level uniform design was employed to investigate the effects of time, solid-to-liquid ratio and NaOH concentration on the yield of protein extract. Through quadratic polynomial stepwise regression analysis, the optimum extraction conditions were determined as follows: extraction time 12 h, solid-to-liquid ratio 1:26, NaOH concentration 0.2%. Under such conditions, the yield of protein extract obtained from Ginkgo biloba L. seeds was 99.99 mg/g, and the recovery of protein was 89.14%. The extract obtained showed a superoxide anion free radical scavenging rate of 38.83% and a reducing power A700 of 0.807, thereby having excellent antioxidant effect and being worth further processing and utilizing.

Key words: uniform design, extraction, Ginkgo biloba L., protein