Wheat gluten deamidation: structure, allergenicity and its application in hypoallergenic noodles

Abstract

BACKGROUNDWheat gluten (WG) containing gliadin and glutenin are considered the main allergens in wheat allergy due to their glutamine‐rich peptides. Deamidation is a viable and efficient approach for protein modifications converting glutamine (Gln) into glutamic acid (Glu), which may have the potential for allergenicity reduction of WG.RESULTSDeamidation by citric acid (CA) was performed to study the effects on structure, allergenicity, and noodle textural properties of wheat gluten (WG). WG was heated at 100 °C in 1 M CA to yield deamidated WG with degrees of deamidation (DD) ranging from DWG‐25 (25% DD) to DWG‐70 (70% DD). FT‐IR and intrinsic fluorescence spectroscopy results suggested the unfolding of WG structure during deamidation, and SDS‐PAGE showed molecular weight shifts at 35‐63 kDa region, suggesting that the deamidation mainly occurred on LMW‐GS subunits and γ‐ gliadin of the WG. ELISA of deamidated WG revealed the decrease in absorbance and immunoblotting indicated the intensities of protein bands at 35‐63 kDa decreased, which suggested that deamidation of WG might have caused the more loss of epitopes than the generation of new epitopes caused by unfolding of WG, and thereby reduction of the immunodominant IgE binding capacity ultimately leading to the decrease of allergenicity. DWG‐25 was used in the preparation of recombinant hypoallergenic noodles, and the hardness, elasticity, chewiness, and gumminess improved significantly by the addition of azodicarbonamide.CONCLUSIONOur work showed the potential for deamidation of WG products used in novel hypoallergenic food development.This article is protected by copyright. All rights reserved.