Abstract:The defatted soybean meal was hydrolysised by alcalase to explore the optimal preparation parameters of calciumchelated soybean peptides, and the properties of alciumchelated soybean peptides were analyzed. The effects of mass ratio of peptide and calcium, chelating temperature, pH and chelating time on calcium binding capacity were studied, and the chelating process was optimized by Box-Benhnken experimental design and response surface methodology (RSM). The results showed that the optimum chelating conditions were as follows: ratio of peptide to calcium was 16, chelating temperature was 38℃, chelating time was 44min, and pH value was 66. Under the optimal conditions, the calcium content was the highest (7873mg/g) in calciumchelated soybean peptides. Moreover, it was concluded that the solubility of the finally obtained calciumchelated soybean peptides was 9859%. Furthermore, the molecular mass distribution of soybean peptidecalcium chelate was also determined by highperformance liquid chromatography (HPLC). The proportion of peptides with a relative molecular weight higher than 5000Da was 176%, peptides with a relative molecular weight lower than 5000Da accounted for 9824%, and peptides with molecular weight lower than 1000Da accounted for 8024%. Among them, the peptides with the relative molecular weight of 180~500Da accounted for the largest proportion. It provided a new method for the research and development of new soybean nutrition and synthesis of new calcium supplements.