Abstract:

In order to develop an enzymatic hydrolysis procedure for the preparation of egg white protein derived angiotensin converting enzyme (ACE) inhibitory peptides, 4 proteases were used to hydrolyze egg white protein alone, and trypsin was the selected enzyme due to the largest ACE inhibitory ratio of hydrolyzed egg white protein. In order to optimize 3 parameters (namely hydrolysis time, substrate concentration and enzyme-to-substrate ratio) affecting the trypsin hydrolysis of egg white protein, central composite design was employed to establish a mathematical regression model for the ACE inhibitory ratio of hydrolyzed egg white protein with respect to the parameters, followed by employing response surface methodology (RSM) to investigate the interactive effects among the independent variables on the function. The results showed that the optimum values of the independent variables were found to be: hydrolysis time 4.87 h, substrate concentration 3.06% and enzyme-to-substrate ratio 2.91% and that the corresponding value of the function was 50.73%.

Key words: egg white protein, enzymatic hydrolysis, ACE inhibitory peptides, response surface methodology, trypsin