Allergen detection in commercial foods

The frequent use of precautionary food allergen labeling statements such as “may contain” poses challenges to allergic individuals relying on such labeling to determine whether a food is safe to consume. To survey the frequency at which these precautionary statements indicate allergen contamination in commercial foods we developed a multiplexed liquid chromatography-mass spectrometry assay targeting 14 common allergens. For each allergen, we selected two or more tryptic peptides belonging to two or more clinically-recognized allergenic proteins by following one of two approaches. For certain allergenic proteins, a wealth of existing mass spectrometry literature suggests ideal tryptic peptide targets. In these cases, such for milk proteins Bos d 5 and Bos d 9, as well as peanut protein Ara h 3, we chose peptides using the Allergen Peptide Browser (APB), a freely available online database we developed. To choose peptides for the remaining allergenic proteins, as well as validate our choices, we applied shotgun proteomics to pure allergen protein extracts of the aforementioned allergens.