Effects of different cooking methods on peanut allergenicity

Abstract

Peanut allergy is a type of serious food allergy worldwide. In this study, peanuts were treated with two different cooking methods. The effect of cooking on digestion stability was evaluated by simulated gastrointestinal digestions. The effects of cooking on the allergenicity were assessed by immunoblotting, passive cutaneous anaphylaxis (PCA) mice model and rat basophilic leukemia (RBL)-2H3 cell model. Results showed that raw peanuts were more stable to digestion than boiled and fried peanuts. SDS-PAGE showed that the quantities of allergens Ara h 1 (64 kDa), Ara h 2 (20 kDa), and Ara h 3 (38 kDa) in the boiled and fried peanuts were all reduced. Meanwhile, immunoblotting revealed the IgE binding capacities of boiled and fried peanuts were decreased significantly, especially the fried peanuts. In the PCA mice model, the vascular permeability of allergic mice, as well as the release of histamine, were both alleviated in mice gavaged with boiled and fried peanuts compared with raw peanuts. Lastly, the release of β-hexosaminidase of RBL-2H3 cells treated with boiled and fried peanuts was significantly decreased compared with the raw peanuts. In addition, the analyses of circular dichroism (CD) spectra showed that the α-helical content of peanut proteins was decreased after boiling and frying, indicating the structure stability of peanut allergens decreased. The analyses of ultraviolet (UV) spectra showed that aromatic amino acid residues were exposed, causing the change of the tertiary structure of peanut allergens after boiling and frying. In conclusion, the allergenicity of peanuts was significantly reduced after boiling and frying, especially frying.