The effects of roasting on the allergenic properties of peanut proteins.
BACKGROUND
Because of the widespread use of peanut products, peanut allergenicity is a major health concern in the United States. The effect or effects of thermal processing (roasting) on the allergenic properties of peanut proteins have rarely been addressed.


OBJECTIVE
We sought to assess the biochemical effects of roasting on the allergenic properties of peanut proteins.


METHODS
Competitive inhibition ELISA was used to compare the IgE-binding properties of roasted and raw peanut extracts. A well-characterized in vitro model was used to test whether the Maillard reaction contributes to the allergenic properties of peanut proteins. The allergic properties were measured by using ELISA, digestion by gastric secretions, and stability of the proteins to heat and degradation.


RESULTS
Here we report that roasted peanuts from two different sources bound IgE from patients with peanut allergy at approximately 90-fold higher levels than the raw peanuts from the same peanut cultivars. The purified major allergens Ara h 1 and Ara h 2 were subjected to the Maillard reaction in vitro and compared with corresponding unreacted samples for allergenic properties. Ara h 1 and Ara h 2 bound higher levels of IgE and were more resistant to heat and digestion by gastrointestinal enzymes once they had undergone the Maillard reaction.


CONCLUSIONS
The data presented here indicate that thermal processing may play an important role in enhancing the allergenic properties of peanuts and that the protein modifications made by the Maillard reaction contribute to this effect.
Maleki
S J
SJ
USDA-ARS-Southern Regional Research Center, New Orleans, LA 70124, USA.
Chung
S Y
SY
Champagne
E T
ET
Raufman
J P
JP
D000485:Allergens / Q000276:immunology / Q000502:physiology; D010367:Arachis / Q000276:immunology*; D005512:Food Hypersensitivity / Q000209:etiology* / Q000276:immunology*; D006358:Hot Temperature / Q000009:adverse effects*; D006801:Humans; D007073:Immunoglobulin E / Q000378:metabolism; D010936:Plant Extracts / Q000737:chemistry / Q000528:radiation effects; D011485:Protein Binding / Q000502:physiology; D013329:Structure-Activity Relationship
D000485:Allergens; D010936:Plant Extracts; D007073:Immunoglobulin E