Kinetics of Hydrolysis of Egg White Protein by Pepsin

Ruan Ch.-Q., Chi Y.-J., Zhang R.-D. (2010): Kinetics of hydrolysis of egg white protein by pepsin. Czech J. Food Sci., 28: 355–363. Taking into account the enzyme inactivation and substrate inhibition, the bioreaction mechanism and kinetics characteristic of egg white protein (EWP) enzymatic hydrolysis by pepsin were investigated. A logarithmic equation h = (1/b) ln (1 + abt) indicating the relationship between the degree of hydrolysis (DH) and time was established. For EWP-pepsin system, the reaction mechanism could be deduced from a series of experimental results at different temperatures, pH values, substrate concentrations, and enzyme concentrations. The reaction kinetics and thermodynamic constants (KS = 3916.5 g/l, k2 = 17 202.86 min–1, kd = 21 962.03, Ea = 56.89 kJ/mol, Ed = 51.99 kJ/mol) were responsible for the empirical equations. The results of nonlinear regression of the proposed kinetic model agreed with the experimental data, i.e. the average relative error was less than 5%. As a conclusion, the kinetic equations can be used to fit the enzymatic hydrolysis process of egg white protein and to optimise the operating parameters of bioactive peptides preparation for the bioreactor design.