THE EFFECTS OF BOILING, FRYING AND ROASTING ON THE ALLERGENICITY OF PEANUTS

Authors: Schmitt, David; Maleki, Soheila; Chung, Si Yin

Submitted to: Journal of Allergy Clinical Immunology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/1/2004
Publication Date: 4/1/2004
Citation: Schmitt, D.A., Maleki, S.J., Chung, S. 2004. The effects of boiling, frying and roasting on the allergenicity of peanuts. Journal of Allergy Clinical Immunology. 113:520.

Interpretive Summary: Consumption of peanuts is widespread in the United States (U.S.), Great Britain and Canada. The rate of peanut allergies in these countries is also increasing. This increase in the rate of peanut allergies, as well as their persistence and severity, make peanut allergies an increasing health risk. In the U.S., Great Britain, and Canada the majority of peanuts consumed are dry roasted, while in China, which has a lower occurrence of peanut allergies, the majority of peanuts consumed are either fried or boiled. In this study, we will compare the effects of boiling, frying, and roasting on Ara h 1 and Ara h 2, the major allergens found in peanuts. Samples obtained from boiled, fried, and roasted peanuts will undergo various tests to determine their effects on the ability of peanuts to induce peanut allergies. These tests demonstrate that thermal processing altered peanut proteins, especially the major peanut allergens Ara h 1 and Ara h 2, which resulted in decreased solubility and increased ability of these proteins to induce an allergic reaction to peanuts. We previously demonstrated that roasting peanuts increased the ability of peanuts to induce allergies to peanuts. The results of this study show that boiling and frying peanuts also increases the ability of peanuts to induce allergies to peanuts.

Technical Abstract: The use of peanuts and peanut products is widespread in the United States, Great Britain, and Canada. The prevalence of allergies to peanuts is increasing in these countries, and coupled with the persistence and severity of these allergies, makes them an increasing public health risk. In the United States, Great Britain, and Canada, the majority of peanuts consumed are roasted to improve flavor. In contrast, in China, which has a much lower occurrence of peanut allergies, the majority of peanuts consumed are either boiled or fried. In this study, we will compare the effects of boiling, frying, and roasting on the allergenicity and solubility of Ara h 1 and Ara h 2. The soluble and insoluble fractions of extracts from boiled, fried, and roasted peanuts will undergo sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in order to separate individual protein on a gel. The gel will either be stained with Gel-Code Blue stain to visualize the proteins, or the proteins will be transferred to PVDF membrane, which will then undergo Western blot analysis. SDS-PAGE showed that in all three samples, Ara h 1 and Ara h 2 became less soluble as the length of exposure to heat increased. This was confirmed by Western blot analysis using antibodies against Ara h 1 and Ara h 2. These analyses also demonstrated that the various forms of heating induces differential modification of Ara h 1 and Ara h 2. In addition, binding of IgE from peanut-allergic individuals is increased in all samples tested. Frying and boiling, as well as roasting, decreases the solubility and increases the allergenicity of Ara h 1 and Ara h 2.