Developing innovative methods for detecting emerging food allergens and evaluation of their impact on consumer health: an integrated approach

DEVELOPING INNOVATIVE METHODS FOR DETECTING EMERGING FOOD ALLERGENS AND EVALUATION OF THEIR IMPACT ON CONSUMER HEALTH: AN INTEGRATED APPROACH - IntegrALL




The term food allergy is used to describe an adverse immune response to foods. A recent multi-center study led by EpidemAAITO Consortium showed how 2% of Italian adults are likely to have some kind of food allergy. Even small amounts of allergen can trigger allergic reaction; therefore the only possible approach is the avoidance of the offending food from the diet. Food allergy is an important health problem in most industrialized countries and it is extremely stressing for sensitized people and also for their families. Since 2003, the European Union adopted the Directive 2003/89/EC (later modified by amendments), that established a list of ingredients with a potential allergenic effects for which labelling is mandatory. Even though the present legislation on food labelling does not regulate the presence of allergens in traces, many food companies try to commercialize foods which are highly safe for allergic people. This means to have at disposal analytical methods that are sensitive enough to identify minute amounts of food allergen in complex matrices. Allergens in traces are mainly associated with cross-contamination due to the involuntary transfer of an ingredient from a food to another, both in industrial and domestic environment. Food industry is normally requested to follow specific guidelines, in order to minimize the problem when the same equipment is used for processing different foods. Since it has not been established a threshold that is objectively safe for the most sensitive patients, the role of minute amounts of cross-contaminating allergens in clinical events is still debated.



As previously highlighted, the possible presence of allergen traces has generated a new request for sensitive detection methods. Widely applied current methods are usually based either on a direct detection of the allergens by an antibody (such as ELISA, lateral flow devices or similar) or on an indirect detection through PCR, for detecting DNA of allergenic ingredients in foods. New methods based on LC/MS detection of proteolytic peptides derived from allergenic proteins have recently been proposed in the literature. In order to produce reliable and inter-comparable analytical results, the analytical methods should undergo validation through inter-laboratory studies.



Tree nuts are frequently responsible for IgE-mediated reactions and pistachio is increasingly associated with both acute reactions and anaphylactic shock. Similarly, pine nut is also known to be a source of food allergens, but current incidence and allergens characterization are still under investigated. Finally, only few studies on almond allergy are available, although symptoms can be severe and anaphylactic reactions have been reported. Pine nut and almond, as well as pistachio, are typical Italian food products, used as such or as ingredients in complex food matrices of vegetable (e.g. pesto, chocolate) and animal origin (e.g. mortadella). Other animal derived sausages can be cross-contaminated particularly by pistachios. As previously confirmed by many studies, only a few part of allergens identified is inactivated through industrial or homemade thermal processing. The effect of proteolysis, high pressure, as well as other unconventional approaches (e.g. microwaves and high power ultrasounds) was previously investigated. Moreover, many food allergens are considered thermal resistant, because their allergic potential is correlated with linear small peptides. Most serious adverse reactions to allergenic foods, up to anaphylaxis, are often associated to resistance to gastrointestinal digestion. Thus, it is important to know allergen susceptibility to digestion in order to assess their level of potential danger.