Abstract: In order to evaluate the effect of roasting on the potential allergenicity of peanut allergen Ara h 1, total protein was extracted from raw and roasted peanuts with chaotropic salt solution and submitted to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. The major peanut allergen Ara h 1 separated in the gel was analyzed by mass spectrometry (MS) and Swiss-Model. SDS-PAGE results showed that the roasted peanut protein sample were separated into one macromolecular aggregate band and multiple scattered protein bands, indicating that the protein could aggregate or degrade during roasting. In raw peanut samples, 70 Ara h 1 peptides were detected with a coverage rate of 79.2%. After roasting, 40 of these peptides were found to disappear, but one new peptide was acquired, and the coverage rate consequently decreased to 43.9%. The 71 peptides involved 18 linear IgE-binding epitopes of Ara h 1, and 16 epitopes in raw peanuts were destroyed after enzymatic hydrolysis, while only 12 were destroyed in roast peanuts. Roasting could enhance the allergenicity of peanut Ara h 1 by damaging the spatial structure of the protein and masking some cleavage sites to protect linear IgE-binding epitopes from enzymatic cleavage.

Key words: roasting; peanut; Ara h 1; mass spectrometry; structure; allergenicity