Allergenic properties of enzymatically hydrolyzed peanut flour extracts

Int Arch Allergy Immunol. 2013;162(2):123-30. doi: 10.1159/000351920. Epub 2013 Jul 31.

Abstract

Background: Peanut flour is a high-protein, low-oil, powdered material prepared from roasted peanut seed. In addition to being a well-established food ingredient, peanut flour is also the active ingredient in peanut oral immunotherapy trials. Enzymatic hydrolysis was evaluated as a processing strategy to generate hydrolysates from peanut flour with reduced allergenicity.

Methods: Soluble fractions of 10% (w/v) light roasted peanut flour dispersions were hydrolyzed with the following proteases: Alcalase (pH 8.0, 60°C), pepsin (pH 2.0, 37°C) or Flavourzyme (pH 7.0, 50°C) for 60 min. Western blotting, inhibition ELISA and basophil activation tests were used to examine IgE reactivity.

Results: Western blotting experiments revealed the hydrolysates retained IgE binding reactivity and these IgE-reactive peptides were primarily Ara h 2 fragments regardless of the protease tested. Inhibition ELISA assays demonstrated that each of the hydrolysates had decreased capacity to bind peanut-specific IgE compared with nonhydrolyzed controls. Basophil activation tests revealed that all hydrolysates were comparable (p > 0.05) to nonhydrolyzed controls in IgE cross-linking capacity.

Conclusions: These results indicate that hydrolysis of peanut flour reduced IgE binding capacity; however, IgE cross-linking capacity during hydrolysis was retained, thus suggesting such hydrolysates are not hypoallergenic.

MeSH terms

  • 2S Albumins, Plant / immunology*
  • Antigens, Plant / immunology*
  • Arachis / immunology
  • Arachis / metabolism
  • Binding Sites, Antibody
  • Endopeptidases / metabolism
  • Glycoproteins / immunology*
  • Humans
  • Immunoglobulin E / immunology
  • Peanut Hypersensitivity / immunology*
  • Pepsin A / metabolism
  • Peptide Fragments / immunology
  • Plant Extracts / immunology*
  • Plant Proteins / immunology
  • Proteolysis
  • Subtilisins / metabolism

Substances

  • 2S Albumins, Plant
  • Antigens, Plant
  • Ara h 2 allergen, Arachis hypogaea
  • Glycoproteins
  • Peptide Fragments
  • Plant Extracts
  • Plant Proteins
  • Immunoglobulin E
  • Endopeptidases
  • flavourzyme
  • Subtilisins
  • Pepsin A