Effect of heat treatment on lactoperoxidase activity in camel milk: A comparison with bovine lactoperoxidase

The thermal inactivation of lactoperoxidase (LP) in camel and bovine milk was studied and compared in a temperature range of 67-73 °C. The analysis of inactivation rate constant (k) data for the process of thermal denaturation of LP in camel and bovine milk showed monophasic inactivation pattern. Based on the thermal death time model, decimal reduction time (D) and inactivation rate constant (k) values of LP in camel milk were more decreased and increased, respectively with increasing temperature in respect of the bovine LP. The corresponding thermal sensitivity values (z) calculated for camel and bovine LP were 6.42 °C and 4.7 °C, respectively. Thermodynamic analysis of LP showed lower values for activation energy and change in enthalpy of denaturation in camel than bovine milk. Overall the results obtained in this study suggest a lower heat stability of camel LP than in its bovine counterpart.