Determination of the allergenicity of various hazelnut products by immunoblotting and enzyme allergosorbent test inhibition

Although allergic reactions to hazelnuts are common especially in Europe, there are only a few investigations with regard to the influence of processing on the IgE-binding potency of hazelnut proteins. In this study the allergenicity of different hazelnut products, such as chocolate, nougat products, croquant or cookies, was examined by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE), immunoblotting and enzyme allergosorbent test (EAST) inhibition experiments using sera of 17 hazelnut-allergic individuals. In only a few cases did the immunoblotting experiments yield positive results as regards the allergenicity of the investigated products. By means of EAST inhibition a residual IgE-binding potency could be detected in almost all of the product extracts. Therefore hazelnuts are a potential hazard to allergic people even as an ingredient of processed foods.