β-Lactoglobulin heat denaturation: A critical assessment of kinetic modelling

Bovine whey protein β-lactoglobulin (β-lg) will denature above 70 °C. Denaturation may contribute positively or negatively to food functionality, so it is important to control the degree of denaturation during milk processing. This work critically examined the kinetic modelling of β-lg denaturation in water, buffer or milk at 70–150 °C using the general rate law for a single-species reaction and the Arrhenius equation. Several published datasets, originally analysed in linearised form, were re-analysed with nonlinear regression, which preserves the error structure of data and estimates the precision of parameters. This work discusses statistical best practice for modelling the heat denaturation of β-lg, explores the criteria for using 2- or 3-parameter regression equations, and proposes new approaches for modelling the concentration- and temperature-dependence of denaturation rates. These new approaches improved the accuracy and precision of kinetic parameter estimates, and revealed new details of how solution conditions influence β-lg denaturation rates.