Effects of Pulsed Electric Fields and Thermal Processing on the Stability of Bovine Immunoglobulin G (IgG) in Enriched Soymilk

To investigate influences of pulsed electric field (PEF) on bovine IgG immunoactivity, soymilk enriched with hyperimmunized dairy milk protein concentrate was subjected to PEF and thermal treatments. Thermal treatment at 78.8 °C for 120 s inactivated 5.1 logs in natural flora and resulted in 86% decrease in IgG activity PEF at 41 kV/cm for 54 μS inactivated 5.3 logs of natural flora and resulted in no significant change (P > 0.05) in bovine IgG activity. Specific antigen-binding activity of bovine IgG against Salmonella enteritidis showed parallel correlation with the measurement of IgG concentration. No further significant change in IgG immunoactivity was observed during a 10-wk storage at 4°C in PEF-, thermally-, or un-treated samples.