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ARS Home » Southeast Area » New Orleans, Louisiana » Southern Regional Research Center » Food Processing and Sensory Quality Research » Research » Publications at this Location » Publication #204592

Title: Peanut Allergens and Processing

Author
item Maleki, Soheila
item Schmitt, David
item YAMAKI, K. - NAT. FOOD RES. INSTIT.
item SHINOHARA, K. - NAT. FOOD RES. INSTIT.
item Champagne, Elaine

Submitted to: United States Japan Natural Resources Protein Panel
Publication Type: Proceedings
Publication Acceptance Date: 8/2/2005
Publication Date: 10/1/2005
Citation: Maleki, S.J., Schmitt, D.A., Yamaki, K., Shinohara, K., Champagne, E.T. 2005. Peanut Allergens and Processing. United States Japan Natural Resources Protein Panel. 288-290.

Interpretive Summary: It has been suggested that boiling or frying of peanuts lead to less allergenic products than roasting. In this study, we have compared the fate of the major peanut allergens in the context of peanuts subjected to boiling, frying, or roasting. As opposed to previous work, both the soluble and insoluble fractions of extracts from boiled, fried, and roasted peanuts were examined for allergenicity using human serum from allergic patients and other specific antibodies. We found that in all three treatments, the major allergens, Ara h 1, one of the major peanut allergens, and to a lesser extent, Ara h 2, a second major allergen, became less soluble with increasing time of exposure to heat. These analyses also demonstrated that the various forms of heating can induce differential modification of Ara h 1 and Ara h 2. In addition, binding of human serum antibodies from peanut-allergic individuals is enhanced with increased time of roasting, boiling, and frying. IgE binding to insoluble peanut fractions is much higher than to the soluble ones. In conclusion, the differences in physical properties due to processing, IgE binding, and solubility of the major allergens in roasted, fried, and boiled peanuts may not explain the large discrepancies between the prevalence of peanut allergy in countries such as China and developed Western countries. However, alteration of other properties due to processing, such as digestibility and other factors, remain untested.

Technical Abstract: It has been suggested that boiling or frying of peanuts lead to less allergenic products than roasting. In this study, we have compared the fate of the major peanut allergens in the context of peanuts subjected to boiling, frying, or roasting. As opposed to previous work, both the soluble and insoluble fractions of extracts from boiled, fried, and roasted peanuts underwent sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis using human serum IgE and specific anti-Ara h 1 and Ara h 2 antibodies. SDS-PAGE showed that in all three treatments, the major allergens, Ara h 1 and to a lesser extent Ara h 2, became less soluble with increasing time of exposure to heat. 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 can induce differential modification of Ara h 1 and Ara h 2. In addition, binding of IgE from peanut-allergic individuals is enhanced with increased time of roasting, boiling and frying. IgE binding to insoluble peanut fractions is much higher than to the soluble ones. In conclusion, the differences in physical properties due to processing, IgE binding and solubility of the major allergens in roasted, fried and boiled peanuts may not explain the large discrepancies between the prevalence of peanut allergy in countries such as China and developed western countries. However, alteration of other properties due to processing, such as digestibility and other factors remain untested.