Influence of temperature and pH on the antigen-binding capacity of immunoglobulin G in cheese whey derived from hyper-immune milk

Sweet whey containing immunoglobulin G (IgG), active in vitro against Campylobacter jejuni, was submitted to different treatments (pH 5.0, 6.5 and 8.0; temperatures between 68 and 80 °C and time between 30 and 3600 s) to evaluate the influence of these conditions on the IgG antigen-binding capacity (ABC). ABC losses followed a first-order kinetic reaction at each temperature and pH studied. Kinetic (k and z) and thermodynamic data (EA, ΔH#, ΔG# and ΔS#) were obtained. ABC was not affected by pasteurisation treatments (72 °C, 16 s), which may suggest the possibility of using hyper-immune sweet whey as a source of dairy products with activity against human pathogens.