Modelling of the kinetics of Bovine Serum Albumin enzymatic hydrolysis assisted by high hydrostatic pressure

The aim of this work was to investigate the kinetics of the enzymatic hydrolysis reaction under high pressure and to propose and experimentally validate a model of the hydrolysis reactions, based on a theoretical analysis and experimental evidences. Bovine Serum Albumin (BSA) has been selected as case study, since this protein is a common allergen of bovine meat and whey proteins, responsible for several allergic cross reactions. BSA has been hydrolyzed with alpha-chymotrypsin and trypsin under high pressure (pressure level: 100-600 MPa; temperature: 37 degrees C; hydrolysis time/holding time: 0-25 min). For each set of experimental conditions the hydrolysis degree (HD) has been determined. A zero-order hydrolysis reaction in competition with a simultaneous second order enzyme inactivation reaction have been considered to represent the hydrolysis under pressure, and a mathematic model has been set up to fit the experimental data of HD as a function of the reaction time. The non-linear mathematical model fits the experimental data properly. This substantiated the theoretical approach utilized to represent the reaction's kinetics taking place during enzymatic hydrolysis under pressure. The reaction rate constant and enzyme inactivation constant increased with the pressure level, confirming that high pressure enhances the hydrolysis reaction rates and inactivates the proteolytic enzymes. (C) 2017 Published by Elsevier B.V. on behalf of Institution of Chemical Engineers.