Abstract: The antioxidant and antithrombin properties of egg white protein hydrolysates were studied in this experiment. Four hydrolysates with different degrees of hydrolysis (DH) were obtained using Alcalase 2.4L and Protease N by pH-stat method. The antioxidant and antithrombin properties of hydrolysates were determined. Also, the amino acid composition and the molecular weight distribution of hydrolysates with the highest activities were analyzed. The results showed that the activities of Protease N hydrolysates are higher than those of Alcalase hydrolysates, with the hydrolysate (DH 15%) having the highest antithrombin activity. The amino acids analysis results showed that the contents of seven essential amino acids in two kinds of hydrolysates with DH 15% are 48.11% and 45.80%, respectively, much higher than the content 35.65% of native egg white proteins.Molecular weight distribution analysis results showed that the two hydrolysates with DH 15% have similar peptides compositions. The difference on activities is due to enzyme species used in the hydrolysis for producing peptides with different amino acid sequences.

Key words: egg white, hydrolysates, biological peptides, antioxidant, antithrombin