Denaturation of whey proteins as a function of heat, pH and protein concentration

This study examined the influence of pH and protein concentration on whey protein (WP) denaturation during heating at 140 °C. The denaturation of β-Lg followed first-order reaction kinetics and depended on protein concentration, being minimum at 10%. However, the lowest rate of denaturation was observed at acidic pH, suggesting increased stability at pH 4, which was confirmed by significantly increased solubility and low turbidity, as well as the electrophoretic patterns of the major WP. The results of differential scanning calorimeter tests revealed the concentration-dependence of WP denaturation. Such information may be useful for defining conditions (pH, protein concentration, temperature) required to produce microparticulated whey proteins with improved functional characteristics.