title: Effects of phytic acid on peanut allergens and allergenic properties of extracts.
abstract: Phytic acid would form soluble and insoluble complexes with proteins. Our objective was to determine if phytic acid forms insoluble complexes with major peanut allergens, and if such reaction results in a peanut extract with a lower level of soluble allergens and allergenic property. Extracts from raw and roasted peanuts were treated with and without phytic acid at various pH values and then analyzed by SDS-PAGE and a competitive inhibition ELISA (ciELISA). The ciELISA measured IgE binding using a pooled serum from peanut-allergic individuals. Results showed that phytic acid formed complexes with the major peanut allergens (Ara h 1 and Ara h 2), which were insoluble in acidic and neutral conditions. Succinylation of the allergens inhibited complex formation, indicating that lysine residues were involved. A 6-fold reduction in IgE binding or allergenic potency of the extract was observed after treatment with phytic acid. It was concluded that phytic acid formed insoluble complexes with the major peanut allergens, and resulted in a peanut extract with reduced allergenic potency. Application of phytic acid to a peanut butter slurry presented a similar result, indicating that phytic acid may find use in the development of hypoallergenic peanut-based products.
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, 1100 Robert E. Lee Boulevard, New Orleans, Louisiana 70124, USA. sychung@srrc.ars.usda.gov
authors.forename: Si-Yin
authors.initials: SY
authors.lastname: Chung
authors.forename: Elaine T
authors.initials: ET
authors.lastname: Champagne
mesh_terms: D055516:2S Albumins, Plant; D000485:Allergens / Q000737:chemistry* / Q000276:immunology; D052179:Antigens, Plant; D006023:Glycoproteins / Q000737:chemistry* / Q000276:immunology; D006358:Hot Temperature; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D008239:Lysine / Q000737:chemistry; D008565:Membrane Proteins; D021183:Peanut Hypersensitivity / Q000276:immunology*; D010833:Phytic Acid / Q000737:chemistry / Q000494:pharmacology*; D010940:Plant Proteins / Q000737:chemistry* / Q000276:immunology
chemical_list: D055516:2S Albumins, Plant; D000485:Allergens; D052179:Antigens, Plant; C500889:Ara h 1 protein, Arachis hypogaea; C500890:Ara h 2 allergen, Arachis hypogaea; D006023:Glycoproteins; D008565:Membrane Proteins; D010940:Plant Proteins; D007073:Immunoglobulin E; D010833:Phytic Acid; D008239:Lysine