Immunological identification and characterization of individual food allergens

Food allergies of type-I-allergy are immunoglobulin E (IgE) mediated and ca used by certain proteins or glycoproteins, which are called food allergens. An analytical marker of allergens is the IgE-reactivity to these substance s. Normally food allergens are minor components in allergenic source materi al, which consist of a huge number of chemical different substances. Thus a llergen extraction, separation and immunological detection methods are desc ribed which identify and characterize individual food allergens by a minimu m of manipulation. Favoured separation methods of allergenic extracts are e lectrophoretic ones allowing the combination of highly resolved protein sep arations with immunological detection methods subsumed by the term immunobl otting. These techniques are a useful basis to characterize allergens by ch emical methods. Once the primary protein structure of a food allergen is es tablished, the way is cleared for the identification of epitopes. Epitopes are immunological detectable parts of a protein or glycoprotein generating the interface between chemical structure and immune-system. The nature of e pitopes may differ, for instance, can be conformational, continuous, or bui lt up by glycoconjugates, which determine the stability of food allergens, especially in the case of food processing. Progress in identification and c haracterization of food allergens will improve diagnostics and therapy of f ood allergy. (C) 2001 Elsevier Science B.V. All rights reserved.