Kinetic study of thermal inactivation of potato peroxidase during high-temperature short-time processing.

Thermal inactivation curves for peroxidase in potato extracts were determined in the range of 100 to 140°C for 10 to 100 sec. The capillary tube method was used to obtain isothermal conditions. The come-up time for the capillary tubes was accurately calculated by analysis method by which thermal inactivation kinetics of enzymes in relation to high temperature processing would be more easily detected. Heat inactivation of potato peroxidase followed first-order reaction kinetics and yielded a curved Arrhenius plot for the temperature dependence at high temperatures. Kinetics parameters, k and Ea, were calculated for potato peroxidase. At temperature range of 100-140°C, the activation energy of peroxidase was lower than that in the range of 78-84°C. It could be elucidated by the scheme of thermal inactivation pathway.