Optimization Investigation of Extraction Technology of Protein in Astragali radix by Single Factor Test and Orthogonal Test

Objective: To optimize the extraction technology of protein in Astragali radix. Methods: The optimized extraction technology was investigated by using single factor test and orthogonal test with the content of water- soluble protein as the index for the first time which was determined by the method of coomassie brilliant blue staining. In this study,the effect of solid- liquid ratio,pH,temperature and time on the extraction rate was investigated. Results: The optimized extraction technique of protein in Astragali radix was established,that was pH 12,solid- liquid ratio 1∶ 20 and 10 min for extraction at the temperature of 30 ℃. Conclusion: The optimal extraction condition was stable and reliable,and could provide an experimental basis for further study of the bioactive substance of Astragali radix.