Development of methods for multi-allergen detection and quantification in food by mass spectrometry

PhD thesis defended by Mélanie PLANQUE (Prof. Thierry ARNOULD) - 08/06/2018

Prof. Thierry ARNOULD, UNamur, Laboratory of Cellular and Molecular Biology (URBC), Organelle dysfunction (DYSO) group


Nathalie GILLARD (CER Groupe), Philippe DELAHAUT (CER Groupe), Georges LOGNAY (ULg), Fabrice BUREAU (ULg), Gavin O'CONNOR (European Commission), Martine RAES,  présidente (UNamur), Patsy RENARD, co-promoteur (UNamur), Thierry ARNOULD, promoteur (UNamur)


Food allergy is a major public health problem, ranked by the World Health Organization (WHO) as the sixth human health problem, affecting 3 % of adults and 8 % of children. For allergic people, to avoid an allergic reaction, the allergenic food must be totally excluded from the diet. The main objective of this work was to develop methods based on ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) for the detection and quantification of specific peptides from milk, egg, soy, peanut and tree nuts allergens in processed and complex food products (cookies, tomato sauce, ice cream and chocolate). In agreement with VITAL, which has fixed thresholds based on clinical study, a targeted limit of quantification (LOQ), expressed in mg of proteins per kg, must be lower than 0.75 for egg, 2.5 for milk and tree nuts, 5 for peanut and 25 for soy (portion size of 40 g). The output of this work is the delivery of a method allowing the high-sensitivity detection of peptides obtained for 10 allergens within a day, in several food products including processed ones. The limit of quantification (LOQ) of the developed method is 0.5 mg/kg for milk proteins, 2.5 mg/kg for peanut, hazelnut, pistachio, and cashew proteins, 3 mg/kg for egg proteins, and 5 mg/kg for soy, almond, walnut, and pecan proteins. The developed method is able to detect allergen peptides at a concentration lower or equal at VITAL thresholds for all allergens at the limit of detection(S/N>3). The development of sensitive, accurate, robust and reliable analytical methods of detection and quantification of allergens in foodstuff could really allow the improvement of food allergen labeling and thus, provide means for a better protection of food allergic populations.