Allergenic properties of enzymatically hydrolyzed peanut flour extracts.
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.
Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, N.C., USA.
Xiaolei
X
Shi
Rishu
R
Guo
Brittany L
BL
White
Adrienne
A
Yancey
Timothy H
TH
Sanders
Jack P
JP
Davis
A Wesley
AW
Burks
Michael
M
Kulis
D055516:2S Albumins, Plant / Q000276:immunology*; D052179:Antigens, Plant / Q000276:immunology*; D010367:Arachis / Q000276:immunology / Q000378:metabolism; D001666:Binding Sites, Antibody; D010450:Endopeptidases / Q000378:metabolism; D006023:Glycoproteins / Q000276:immunology*; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D021183:Peanut Hypersensitivity / Q000276:immunology*; D010434:Pepsin A / Q000378:metabolism; D010446:Peptide Fragments / Q000276:immunology; D010936:Plant Extracts / Q000276:immunology*; D010940:Plant Proteins / Q000276:immunology; D059748:Proteolysis; D013381:Subtilisins / Q000378:metabolism
D055516:2S Albumins, Plant; D052179:Antigens, Plant; C500890:Ara h 2 allergen, Arachis hypogaea; D006023:Glycoproteins; D010446:Peptide Fragments; D010936:Plant Extracts; D010940:Plant Proteins; D007073:Immunoglobulin E; D010450:Endopeptidases; C412470:flavourzyme; D013381:Subtilisins; D010434:Pepsin A