Optimization of protein extraction from Astragali radix waste by response surface methodology

In order to further research on its activity and providing scientific basis for its resource development and utilization, we determine the best extraction technology of Astragali radix waste protein, making waste into treasure of Astragali radix waste.The effects of extraction temperature, solvent/solid ratio, p H, extraction time and extraction times on the extraction rate of Astragali radix waste were investigated by single factor test.In addition, the extraction conditions were optimized by response surface methodology.Results showed that the protein content of Astragali radix waste was 10.74%±0.13%by kjeldahl method.The optimal extraction conditions of Astragali radix waste protein were as follows:the extraction temperature was 64℃, the solvent/solid ratio was 47∶1 (m L·g^-1) , p H was 12.0 and extraction time was 4.3 h.Under this condition, the theoretical maximum of extraction rate was 46.96%, and the experimental value was 47.03%±0.78%.The extraction condition of Astragali radix waste protein optimized by response surface methodology was accurate and reliable and the regression model has good predictive performance, which can guide the production practice and provide some technical reference for industrial production of Astragali radix waste protein.