Evaluation of protein‐phytochemical interactions in a hypoallergenic edible peanut matrix (813.10)

Abstract

Allergenic peanut proteins (PP) are stable to digestion, remain immunoreactive and trigger IgE‐mediated allergic reactions in PP sensitive individuals. In this study, a hypoallergenic peanut protein‐phytochemical matrix (PPPM), produced by complexing cranberry juice (CB) with light roast peanut flour, was evaluated to determine the nature of protein‐phytochemical interactions and the stability of the binding post‐ingestion. PPPM or unmodified peanut flour were subjected to a simulated gastric fluid digestion. Aliquots of the enzymatic mixture were taken at different time points and inhibited with either sodium bicarbonate (pH ~7‐8) or heat (pH ~2) to stop the digestive process. Digested PP fragments and undigested PP were examined on SDS‐PAGE and screened for their peanut‐specific IgE binding capacity using Western blotting, respectively. SDS‐PAGE revealed that PP were more soluble at a low pH than at a basic pH. PP treated with CB had reduced solubility at both acidic and basic pH, compared to untreated PP. However digestion of both PPPM and unmodified peanut flour resulted in formation of highly soluble small molecular weight PP fragments at either pH. Examination of the Western blots revealed that digested PP fragments or undigested PP from PPPM exhibited altered IgE binding, compared to proteins from unmodified peanut flour. Modification of PP with CB phytochemicals led to the formation of insoluble complexes with altered IgE binding to the protein epitopes, suggesting altered PP digestion and IgE binding capacity.Grant Funding Source: Supported by Everett W. Byrd Endowment and NC State appropriations for NCSU at Kannapolis