Purpose: The purpose of this study was to examine interactions occurring between unprocessed food matrices and allergenic residues, milk and peanut, using commercial ELISAs and describe the type(s) of interaction causing reduced detection.
Methods: Model food matrices containing non-fat dry milk (NFDM), wheat flour, wheat starch, salt, shortening, and water were prepared with varying levels of flour (100, 80, 60, 40, 20, 0% flour), substituting flour with starch when necessary. Analogous non-glutinous matrices incurred with NFDM were prepared without shortening and water (flour, starch, salt). Secondly, samples of a known allergen (NFDM or peanut) concentration and increasing concentrations of flour (0, 25, 250, 2500, 25000, 250000, 300000, 350000, 400000, 450000, 500000, and 550000 ppm) were prepared. Neogen Veratox Total Milk or Neogen Veratox Peanut ELISA kits were used for analysis.
Results: Statistically significant differences (P<0.05) were found between the recovery of milk from glutinous and non-glutinous matrices; recovery was lower in glutinous matrices (77 ± 19%) compared to non-glutinous matrices (117 ± 19%). In the concentration analyses, recovery of milk was lowest (66 ± 15%) at 550,000 ppm flour whereas recovery of peanut was adequate (98 ± 11%).
Significance: Reduced recoveries of allergenic residues by ELISA, particularly milk, are observed in glutinous food matrices and in high flour concentrations. Inadequate detection of residues does not imply reduced allergenicity therefore further understanding of the interaction between allergenic proteins and glutinous food matrices is needed to assure the safety of allergic consumers.