LC-MS/MS quantification of egg allergens across eight avian species in foods: development, validation, and...

Validated analytical methods for egg allergen detection across multiple avian species remain scarce, posing risks for allergic consumers. This study developed and validated an LC-MS/MS method for simultaneous quantification of ovalbumin from eight avian species (chicken, duck, quail, goose, pigeon, turkey, ostrich, and guinea fowl) in processed foods. Species-specific and shared peptides were screened by high-resolution MS, with MRM transitions optimized and thermal stability assessed. Sample preparation included defatting, urea-assisted extraction, tryptic digestion, and SPE cleanup. Using matrix-matched calibration with stable isotope-labeled internal standards, the method achieved, for all eight species, LODs of 0.5-2 mg/kg, LOQs of 2-5 mg/kg, linearity (R² > 0.995), accuracy (80.3%-94.4%), and precision (RSD < 13.3%). Among 26 commercial products, egg allergens were detected in 22 (84.6%); seven (26.9%) were undeclared, exceeding the FAO/WHO reference dose per 100 g serving. This validated protocol provides a reliable tool for multi-species egg allergen surveillance and food labeling compliance.