Submitted to: Journal of Agriculture and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/6/2004
Publication Date: 7/14/2004
Citation: Chung, S., Maleki, S.J., Champagne, E.T. 2004. Cross-linking of peanut proteins by peroxidase and its effects on peanut allergenicity. Journal of Agriculture and Food Chemistry. 52(14):4541-4545. Interpretive Summary: Peanut allergy is a public health issue. The culprits are the peanut proteins people ingest or inhale. We call these proteins allergens. Reducing the allergenic properties of these proteins will be beneficial to the public, especially the children and allergic individuals. In this study, we attempted to reduce the allergenic properties of peanut proteins by using an enzyme called peroxidase. In the experiment, we treated the protein extracts from roasted peanuts with peroxidase. The peroxidase then transformed portions of the peanut allergenic proteins in the extract into big polymers. As a result, levels of the original allergenic proteins were reduced, and the resultant big polymers became less allergenic. The overall allergenic properties of the peroxidase-treated peanut extract was reduced. The finding suggests that peroxidase may have a potential application in the development of hypoallergenic peanut-based beverage products. Peanut allergic individuals, pregnant women, and young children will particularly benefit from these hypoallergenic products. Ultimately, sale and consumption of peanut products are expected to increase, and the peanut industries will continue to grow.
Technical Abstract: Peanut allergy is a public health issue. The culprits are the peanut proteins. Reducing the allergenic properties of these proteins will be beneficial to allergic individuals. In this study, the objective was to determine if peroxidase (POD), which catalyzes protein cross-linking, reduces the allergenic properties of peanut proteins. In the experiments, protein extracts from raw and roasted defatted peanut meals at a pH 9 were incubated with and without POD in the presence of hydrogen peroxide at 37 oC for 60 min. The POD-treated and untreated samples were then analyzed by SDS-PAGE, Western blots, and competitive inhibition ELISA. IgE binding or allergenicity was determined in blots and ELISA. Results showed that POD treatment had no effect on raw peanuts with respective to protein cross-linking. However, a significant decrease was seen in the levels of the major allergens, Ara h 1 and Ara h 2, in roasted peanuts after POD treatment. Also, polymers were formed. Despite this, a reduction in IgE binding was observed. It was concluded that POD induced the cross-linking of mainly Ara h 1 and Ara h 2 from roasted peanuts, and that due to POD treatment, IgE binding was reduced. The finding indicates that POD can help reduce the allergenic properties of roasted peanut proteins.