The changes in antioxidant and pro-oxidant activity of milkwere studied using different heat treatments. At each heating
temperature, samples showed an initial increase and a subsequent decrease in pro-oxidant activity. The latter was associated with an
increase in the antioxidant properties. The changes in the reducing properties of milkupon heating were attributed not only to the
thermal degradation of natural occurring antioxidants, but also to the formation of novel oxidative species in the early stages of the
Maillard reaction. The results indicate that short heat treatments can be potentially responsible for a depletion in the overall
antioxidant properties of milk. By contrast, only the application of severe heat treatments, associated with the formation of brown
melanoidins, allows a recovery, and even a possible increase in milkantioxidant properties.
