Kinetic modeling of polyphenoloxidase inactivation during thermal-assisted high pressure processing in black tiger shrimp (Penaeus monodon)

- Synergistic effect of pressure and temperature on inactivation rate of PPO.
- The nth order model fit well for isobaric inactivation of PPO in shrimp.
- Formulation of a global kinetic model based on Arrhenius and Eyring equations.

High pressure inactivation kinetics of polyphenol oxidase (PPO) was studied in black tiger shrimp (Penaeus monodon), with the applied processing parameters ranging from 300 to 600 MPa, 30-60 °C and 0-15 min for pressure, temperature and holding time, respectively. The inactivation kinetics was demonstrated with pressure pulse effect followed by static pressure-hold period. A synergistic effect of pressure and temperature was noted on inactivation rate of PPO. Enzyme inactivation kinetics followed a 0.97 order reaction within the range of experimental domain. The activation energy (Ea) and the activation volume (Va) values computed to describe the temperature and pressure dependence of inactivation rate constant (k, min−1), decreased with increase in pressure and temperature, respectively. An empirical model was proposed taking into account the pressure and temperature dependence of Ea and Va, to describe the inactivation rate of PPO as a function of pressure and temperature. A good correlation was established between experimental and predicted values of k.