[Kinetics of thermal inactivation of peroxidases in turnips and peas]

The heat inactivation of peroxidase in green peas and turnips grown in Venezuela was determined experimentally at temperatures ranging from 60 degrees C to 76 degrees C for turnips, and between 72 degrees C and 82 degrees C for green peas. The thermal destruction curves obtained were found to be biphasic, following first-order kinetics of inactivation, and with average times for the change of phase of 22.5 sec and 23.8 sec for the turnips and peas, respectively. The activation energies, as calculated by the Arrhenius equation for the first and second inactivation intervals, were 27.1 kcal/mole and 43.5 kcal/mole for turnips, and 34.5 kcal/mole and 28.9 kcal/mole for green peas.