Abstract: In order to extract and utilize small molecular peptides from the sunflower calathide that could reduce uric acid and dissolve tophi, the extraction conditions were optimized by the enzymatic hydrolysis method with the yield of small molecular peptides as the index, and the alkaline protease was determined to be the most ideal enzyme. The effects of materialtoliquid ratio, time, temperature, pH value and enzyme amount on the yield of small molecular peptides were investigated by single factor
 test. The response surface MaskBehnken test was used to optimize the extraction of small molecular peptides from sunflower calathide by enzymatic hydrolysis method. The results show that the optimum technological conditions are adding alkaline protease, m(material)∶V(liquid)=1∶15, the amount of enzyme is 2%, the pH=9.0, the temperature is 55 ℃, and the time is 2 h. The highest yield of small molecular peptides from sunflower calathide is (42.41±0.01)%.

Key words: sunflower calathide, small molecular peptide, extraction, single factor, enzymatic hydrolysis method, response surface method