Effect of high pressure and pulsed electric field on denaturation and allergenicity of Pru p 3 protein from peach.

The effect of high pressure (HP) and pulsed electric field (PEF) treatments combined or not with heat on denaturation and allergenicity of Pru p 3, the major allergenic protein of peach, was studied. Denaturation of Pru p 3, determined by ELISA using rabbit IgG, occurred when the protein was treated at 500 and 600 MPa at 20 °C and at 400 MPa at 50 °C. PEF treatment at 25 kV/cm at 50 °C denatures Pru p 3. Allergenicity of Pru p 3 was estimated in vitro by a competitive fluorescent immunoassay using three pools of sera from peach allergic patients. Any treatment applied did not show to influence the binding of Pru p 3 to IgE. When HP and PEF treated samples were tested by the prick test, the skin response was dependent on the particular sensitization of each patient, obtaining an increased reaction in more than 50% of individuals.