Proteomic analysis of food allergens

Food allergies are a growing health problem that generate high costs for health systems. Food allergies have a prevalence of 6-8% in children and 2-3% in adults, which is increasing in the last 10 years due to industrialization. The wide variety of ingredients containing food allergens, in combination with the high number of product formulations and processing methods to produce food makes allergen detection a challenge. It is important to highlight that even trace amounts of allergens are able to elicit allergic reactions and the commercialization of food products with a potential health risk is forbidden (European Union Regulation (EU) 178/2002). Hence, precautionary allergen labeling must be provided in the different food products. In addition, this creates a real need for the development of highly sensitive and reliable techniques that allow the detection and quantification of multiple allergens present in trace amounts. This, together with the possibility to perform new allergen discovery studies (shotgun proteomics), makes Proteomic approaches a widely used methodology in this field. In this chapter we summarize the current knowledge regarding food allergies and the proteomic studies performed for the analysis of the different allergens. We briefly describe immunological processes underlying the different types of food allergies, the causative allergens involved in these processes, as well as the different proteomic approaches developed to identify (e.g., LC-MS/MS) and quantify (e.g., targeted proteomics such as selected/multiple reaction monitoring, SRM/MSM) these allergens in different conditions (e.g., complex mixtures, ultra-processed food, etc). Moreover, we have performed a comprehensive review of the different allergens and proteomic studies carried out in the field of plant food allergies, including gluten related disorders (GRDs), pollen-fruit allergy syndrome (PFAS), legumes allergy, and tree-nuts allergy, as well as animal food allergies, including cow´s milk, red meat, egg, fish, and shellfish allergies.