Heat and pressure treatments effects on peanut allergenicity

Peanut allergy is recognized as one of the most severe food allergies. The aim of this study was to investigate the changes in IgE binding capacity of peanut proteins produced by thermal-processing methods, including autoclaving. Immunoreactivity to raw and thermally processed peanut extracts was evaluated by IgE immunoblot and skin prick test in patients with clinical allergy to peanut. Roasted peanut and autoclaved roasted peanut were selected for IgE ELISA experiments with individual sera, immunoblot experiments with antibodies against peanut allergens (Ara h 1, Ara h 2 and Ara h 3), digestion experiments, and circular dichroism spectroscopy. In vitro and in vivo experiments showed IgE immunoreactivity of roasted peanut proteins decreased significantly at extreme conditions of autoclaving. Circular dichroism experiments showed unfolding of proteins in autoclave treated samples, which makes them more susceptible to digestion. Autoclaving at 2.56 atm, for 30 min, produces a significant decrease of IgE-binding capacity of peanut allergens.