Detection of Allergens in a Multiple Allergen Matrix and Study of the Impact of Thermal Processing

The objectives of this work were to (a) determine the percentage recovery of three allergens (casein, egg and soy) simultaneously incurred in a flour matrix, (b) investigate the effect of different baking periods on allergen recovery using two different methods of allergen detection, namely enzyme linked immunosorbent assay (ELISA) and flow cytometry, and c) determine the solubility of proteins in the prepared blank dry cookie mix flour, non-cooked dough and baked cookies after baking at different temperatures using different extraction buffers. Sodium carbonate buffer was least effective in extracting protein. For the blank flour and non-cooked samples, PBS buffer was the most effective at extracting protein, whereas the Tris buffer gave the highest protein recoveries among the three buffers for the cooked samples. For all three allergens, thermal processing greatly reduced allergen recovery in the processed food matrix as detected using both the commercial ELISA kits and flow cytometry. Moreover, allergen recovery in the cooked samples decreased with increasing processing temperatures and ranged from 96% to 20% for casein, 26.5% to 3.7% for soy and 12.8% to 0% for egg in an instance where a false negative was detected when a high processing temperature of 450°F was employed.