Peptide array-based inhibition ELISA for evaluating antigenicity in infant formulas.

With increased awareness among consumers regarding food safety and security, food allergen control has become an indispensable requirement in the food industry. Although several methods for detecting allergens in food products are available, highly sensitive techniques are required. In this study, we developed a technique named as peptide array-based inhibition enzyme-linked immunosorbent assay (ELISA), Pep-iEIA, for evaluating antigenicity and detecting cow's milk antigen in infant formula products, using a peptide array consisting of a series of overlapping peptides found in allergenic milk proteins. Pep-iEIA was used to examine five cow's milk-based infant formulas with different degrees of hydrolyzation, and the assay offered both more sensitive detection and detailed analysis of remaining antigenic peptides in allergen compared to conventional ELISA. The antigenicity level of the allergenic peptides identified using Pep-iEIA was confirmed by surface plasmon resonance assay. We believe that Pep-iEIA will be highly useful for antigenicity evaluation of dairy products consumed by infants and patients with cow's milk allergy.