Effects of in vitro Digestion on the IgE-binding Activity of Proteins from Hazelnuts (Corylus avellana)

The allergenicity of hazelnuts treated with different proteolytic enzymes was examined and compared by SDS-PAGE / immunoblotting and EASTinhibition experiments using sera of 16 hazelnut allergic individuals. 30 min treatment with the enzymes protease, elastase and trypsin eliminated the allergenicity of the hazelnut proteins, which can be shown by means of immunoblotting experiments. EASTinhibition experiments reveal only a reduction of allergenicity. Treatment with pancreatin led to a slight decrease in the IgE binding activity of the main hazelnut allergens after 30 min and to an elimination after 60 min. Hydrolysis with pepsin at pH 1.2 resulted in a slight decrease of allergenic activity after 60 min. A complete elimination did not even appear in two of seven patients' sera after 240 min of hydrolysis with pepsin. The results reveal that the IgE-binding proteins in hazelnuts are not very stable to in vitro digestion with proteolytic enzymes. (Internet Symposium on Food Allergens 2000, 2(1):1-8 ) food allergy hazelnuts enzymes digestion IgE-binding SDS-PAGE immunoblot EAST-inhibition