Effect of Heat Treatment on Bovine Lactoperoxidase Activity in Skim Milk: Kinetic and Thermodynamic Analysis

Abstract

ABSTRACT: The effect of heat on lactoperoxidase activity in bovine milk was studied over a range of 68 to 76 °C. Values of residual enzymatic activity after different treatments were studied by kinetic analysis, obtaining D‐values and the Z‐value (3.1 °C). Denaturation of lactoperoxidase, measured by loss in activity, can be described as a 1st‐order reaction. Rate constants were calculated, as was the energy of activation, which was 737.69 kJ/mol. Thermodynamic parameters were also calculated. The high value obtained for the variation in enthalpy of activation indicates that a high amount of energy is required to initiate denaturation, probably due to the molecular conformation of lactoperoxidase.