Mass Spectrometry

Biography

Biography: Barbara Prandi

Abstract

Food allergies are adverse reactions to certain food proteins that occur in previously sensitized (IgE mediated) or genetically predisposed (not IgE mediated) subjects. For the severity of these reactions the European Commission approved the Directive 2007/68/EC, which lists all the allergenic foods that must be labelled in food products. Allergen detection methods can be basically divided into PCR-based methods and ELISA-based methods, but in the recent years also mass spectrometry is increasing its diffusion for allergen analysis. Identification of marker peptides allows an extremely specific quantification of allergenic proteins. This approach was used to quantify both single proteins, like the wheat allergens CM3, and complex protein mixtures, like gluten proteins. Mass spectrometry is also a useful technique to understand food allergy mechanism, for example by determining the resistance of different food allergens to gastrointestinal digestion. The higher allergenicity of peach LTP can be explained on the basis of its higher resistance to proteolysis (30% of intact protein at the end of the digestion) compared to apricot LTP (9% intact protein). Celiac disease related peptides were also identified and quantified using the isotopically labeled internal standard method, demonstrating that different wheat lines can produce a significantly lower amount of immunogenic peptides upon digestion. On the opposite, other wheat allergens, such as CM3, are more affected by environmental condition. Mass spectrometry has thus a fundamental role in the study of food allergens, both from the safety perspective (as a tool for allergen detection) and in understanding the molecular features of food allergies.