Effect of Pulsed Ultraviolet Light and High Hydrostatic Pressure on the Antigenicity of Almond Protein Extracts

The efficacy of pulsed ultraviolet light (PUV) and high hydrostatic pressure (HHP) on the IgE binding to the almond extracts was studied using sodium dodecyl sulfate polyacrylamide-gel electrophoresis, Western blot, and enzyme-linked immunosorbent assay (ELISA) probed with human plasma containing IgE antibodies to almond allergens and a polyclonal antibody against almond major protein. Crude almond protein extracts were treated with PUV (3 pulses/s, 10 cm from lamp) for 0.5, 1, 2, 3, 4, 6, 7, and 10 min. In comparison, boiling treatments were also carried out. The HHP treatments were conducted at 600 MPa for 5, 15, and 30 min at three temperatures of 4 A degrees C, 21 A degrees C, and 70 A degrees C. Western blots and indirect ELISA demonstrated a reduction in the levels of allergens and IgE binding in PUV-treated extracts at 7 min, which was found to be the optimal time for PUV exposure. Boiling was not as effective as PUV in reducing the overall IgE-binding of the almond extracts. Unlike PUV, HHP did not affect the allergen levels and IgE binding under the conditions tested.