Effects of cooking methods on peanut allergenicity

Background: Allergy to peanut is a significant health problem. Interestingl y, the prevalence of peanut allergy in China is much lower than that in the United States, despite a high rate of peanut consumption in China. In Chin a, peanuts are commonly fried or boiled, whereas in the United States peanu ts are typically dry roasted, Objective: The aim of this study was to examine whether the method of prepa ring peanuts could be a factor in the disparity of allergy prevalence betwe en the 2 countries. Methods: Two varieties of peanuts grown in the United States were roasted, boiled, or fried. Proteins were analyzed by using SDS-PAGE and immunoblotti ng. Allergenicity was compared by using immunolabeling with sera from 8 pat ients with peanut allergy, Results: The protein fractions of both varieties of peanuts were altered to a similar degree by frying or boiling. Compared with roasted peanuts, the relative amount of Ara h 1 was reduced in the fried and boiled preparations , resulting in a significant reduction of IgE-binding intensity. In additio n, there was significantly less IgE binding to Ara h 2 and Ara h 3 in fried and boiled peanuts compared with that in roasted peanuts, even though the protein amounts were similar in all 3 preparations, Conclusion: The methods of frying or boiling peanuts, as practiced in China , appear to reduce the allergenicity of peanuts compared with the method of dry roasting practiced widely in the United States. Roasting uses higher t emperatures that apparently increase the allergenic property of peanut prot eins and may help explain the difference in prevalence of peanut allergy ob served in the 2 countries.