Steady-state kinetics of tryptic hydrolysis of β-lactoglobulin after dynamic high-pressure microfluidization treatment in relation to antigenicity

Abstract

Our previous research revealed that dynamic high-pressure microfluidization (DHPM) increased the antigenicity of β-lactoglobulin (β-Lg) below 80 MPa, which was related to the unfolding of protein. To test the hypothesis that the unfolding of protein may change proteolytic susceptibility of β-Lg and modulate its antigenicity during the digestion, we developed that the steady-state kinetics of tryptic hydrolysis of β-Lg subjected to DHPM (0.1–80 MPa) have been investigated in relation to the antigenicity in this study. According to the steady-state kinetics analysis, the improved digestion of β-Lg was accompanied with the obvious decrease of antigenicity during the hydrolysis with pressure increasing, reflected by the increase of k c , the decrease of K m, the increase of overall catalytic efficiency (k c/K m), and the increase of the binding volume. It was indicated that although DHPM can increase the antigenicity of β-Lg, the enhanced digestibility of β-Lg at elevated pressure contributed to a decrease of antigenicity during the hydrolysis.