Allergenicity of food and impact of processing

[Extract] Allergy-related diseases are today recognized as reaching epidemic proportions (Simons et al. 2008), with up to 30% of the general population suffering from them. In addition to increasing genetic predisposition ("atopy") of people, changing living conditions in developed as well as in developing countries could all contribute to immune deviation and the development of allergies. Adverse reactions to foods are of considerable importance in today's society, especially given the recent introduction of new allergens as eating habits change (appearance of "exotic" and novel foods), and the use of new industrial processing technologies which result in food ingredients appearing in unexpected forms. In the research efforts in the field of food allergy two main questions are often asked: what makes one person allergic to a particular food ans not the other and why some foods and food proteins are more allergic than others. Investigation in this area of research is much more difficult than investigating inhalant allergens since food proteins are found in a complex matrix and may undergo physicochemical changes during digestion and subsequent uptake by the gut mucosal barrier and presentation to the immune system. The food matrix certainly has great impact on the elicitation of allergic reactions as allergens are differentially released, for example in fat-rich matrices, and enhance allergic reaction (Palmer and Burks 2006). Furthermore, food processing results in mostly water-soluble proteins, which makes the traditional serological analysis of allergenicity difficult. Due to these complex interactions of allergenic proteins with different matrices and the impact of various food processing techniques, research into this area has only begun in the last few years. Our current understanding of the impact of food processing on allergenicity is limited to a few food allergens and clinical studies, which will be discussed in the following section