Submitted to: Journal of Allergy Clinical Immunology
Publication Type: Abstract only
Publication Acceptance Date: 11/22/2010
Publication Date: 2/10/2011
Citation: Chung, S., Champagne, E.T. 2011. Tannic acid as a means to remove peanut allergens. Journal of Allergy Clinical Immunology. 127(2):AB238. Interpretive Summary:
Technical Abstract: Tannic acid (TA) is a polyphenol (commonly found in tea and coffee) that has been used as a treatment for toxic substances and carpet allergens. The objectives were to determine the efficacy of TA’s binding and removal of peanut allergens from peanut butter extracts as insoluble precipitates, and to verify that the allergens remain bound and not released from the precipitates at pH 2 and pH 8 (simulating gastric and intestinal pH). The idea was to keep the allergens bound as TA precipitates, and hypothetically the precipitates would be excreted from the body. TAs at various amounts were added to peanut butter extracts (25 mg/mL), then stirred and centrifuged. The release of peanut proteins from the retrieved precipitates was carried out by re-suspending the precipitates in a buffer, pH 2, followed by a buffer of pH 8 (simulating gastric and intestinal pH). The degree of protein release was evaluated by SDS-PAGE on the supernatants retrieved at pH 2 and 8. IgE binding was performed in ELISA, using a pooled plasma from peanut-allergic individuals. Data showed that the majority of peanut proteins/allergens were removed as precipitates from peanut butter extracts with TA at 5 mg/mL. No allergens were released from the precipitates, even after the latter were re-suspended sequentially in buffers pH 2 and pH 8. By contrast, precipitates obtained from TA at < 5 mg/mL were found to release peanut proteins/allergens at a rate inversely related to the amount of TA added. IgE binding was reduced in accordance with the reduced level of peanut allergens in the supernatants. TA bound and formed precipitates with peanut proteins/allergens. The degree of peanut proteins/allergens binding to TA depended on the amount of TA added. The more TA that was added, the harder the peanut proteins/allergens were released from the precipitates at simulated gastric and intestinal pH. This means that when allergens are not released in the digestive system, they won’t be absorbed, but instead would be excreted as precipitates from the body. The finding indicates that TA may be useful for removal of peanut allergens due to accidental ingestion of peanut products and/or preparation of low-allergen peanut products.