Gluten Detection - Behind the Wells

Jupiter M. Yeung, PhD¹,
Carmen D. Westphal, PhD²,
Dorcas Weber, PhD³
Frances M. DuPont, PhD⁴, USDA, ARS
William J. Hurkman, PhD⁴, USDA, ARS

1. Food Products Association, 2. FDA, CFSAN, 3. Bureau of Chemical Safety, Health Canada, 4.USDA, ARS

Wheat allergy and celiac disease are two distinctly different disorders with a common trigger, gluten. Gluten is a complex mixture of alcohol-soluble prolamins (gliadins in wheat) and alcohol-insoluble proteins glutelins (glutenins in wheat). Wheat flour contains water-soluble albumins and salt-soluble globulins, protein groups which include additional known wheat allergens. Currently, there are seven gluten/gliadin commercial ELISA kits for the detection and quantification of gluten in food samples. While accurate, reliable analytical results are crucial to ensure food safety or enforcement programs for food allergens, data generated from different test kits for the same homogeneous sample are often divergent, making science-based management decisions difficult. To delineate factors contributing to test kit variability, we analyzed different wheat protein fractions as well as different flours by ELISA, SDS-PAGE, immunoblots, and LC/MS/MS. Our findings provide new perspectives on the ELISA test results, including antibody specificities.