This study was carried out to evaluate the application of food irradiation technology as a method for reducing milk allergies. Bovine alpha-casein (ACA) and beta-lactoglobulin (BLG) were used as milk proteins. Using milk-hypersensitive patients' immunoglobulin E (IgE) and rabbit IgGs individually produced to ACA and BLG, the changes of allergenicity and antigenicity of irradiated proteins were observed by competitive indirect enzyme-linked immunosorbent assay. Allergenicity and antigenicity of the irradiated proteins were changed with different slopes of the inhibition curves. The disappearance of the band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and increase of the turbidity showed that solubility of the proteins decreased by radiation, and this decrease might be caused by agglomeration of the proteins. These results indicated that epitopes on milk allergens were structurally altered by gamma irradiation.