Kinetic and thermodynamic studies on the thermal denaturation of bovine milk insulin-like growth factor-I in model systems.

摘要

In this study, kinetic and thermodynamic parameters for heat denaturation of bovine milk insulin-like growth factor-I (IGF-I) in phosphate-buffered saline (PBS) and ultra-high temperature (UHT) milk were determined. The D-values were higher in UHT milk than in PBS at all temperatures. The Z-values were 24.41 degrees C and 27.12 degrees C in PBS and UHT milk, respectively. Heat denaturation of bovine milk IGF-I followed a reaction order of n=1.1. The energies of activation and change in Gibbs free energy, enthalpy and entropy were also compared. The results showed more significant thermal stability of IGF-I in milk than in PBS..