High-pressure and temperature autoclaving of peanuts reduces the
proportion of intact allergenic proteins
Abstract
BACKGROUND Peanut allergy is a particularly common cause of anaphylaxis
and utilization of hospital emergency room resources. Peanut protein
allergens do not appear to denature under normal cooking conditions. We
evaluated the effects of thermal processing on the protein allergens Ara
h 2, associated with a risk for anaphylaxis, and Ara h 8, a protein
analogous to birch pollen associated with oral allergy symptoms. METHODS
Raw, roasted and autoclaved peanuts were evaluated. Solution 1H NMR
spectroscopy was used to obtain molecular profiles and identify chemical
changes across processing conditions. Western blot and ELISA analyses
were used to detect relative levels of specific peanut allergens.
RESULTS NMR analysis of peanut-soaked solutions demonstrated an overall
reduction of total intact protein in autoclaved peanuts as shown by the
broadening of peaks in the spectral regions corresponding to peptide
fragments when compared to raw. The results also showed that autoclaving
reduces the amount of allergenic proteins Ara h 2 (50% reduction) and
Ara h 8 (100% reduction). Upon skin prick testing of allergic subjects,
this differential degradation demonstrated that the autoclaved peanut
could be used to categorize patients into two groups: those at risk for
anaphylaxis and those who only experience oral symptoms to peanut
(predominantly Ara h 2- and Ara h 8-specific IgE, respectively).
CONCLUSION The data reported in this study suggest that high-pressure
and temperature autoclaving reduces the amount of intact protein in the
peanut, including allergenic proteins. This could be further developed
into an improved diagnostic test for peanut allergy.