Allergenicity of hen's egg ovomucoid gamma irradiated and heated under different pH conditions

This study was conducted to evaluate the effect of a treatment combining gamma radiation and heating on the allergenic properties of hen's egg ovomucoid (OM) under basic pH conditions. OM solutions of 2.0 mg/ml with pHs of 7.0, 9.0, and 10.0 were gamma irradiated at 10 kGy, heated at 100 degrees C for 15 min, or both. Half of the treated pH 10.0 sample solution was restored to pH 7.4 by dialysis. OM solutions were tested by a competitive direct enzyme-linked immunosorbent assay formatted with immunoglobulin E from egg-hypersensitive patients. An equation was obtained for quantifying intact OM from the standard curve, and the detected concentration of intact OM was calculated. The concentration of intact OM decreased with irradiation or heating, and the rate of the decrease was higher for a basic pH condition than for the physiological condition. The combination of irradiation and heating was very effective in reducing the amount of intact OM regardless of the pH condition. After treatment, the restoration of the pH to 7.4 did not affect the concentration of OM. The results of this study indicate that a combination of irradiation and heating might be an effective method for reducing egg hypersensitivity resulting from OM.