Evaluation of Gluten Protein Profiles in Hydrolyzed Food Products by a Multiplex-Competitive Enzyme-Linked Immunosorbent Assay.

The apparent gluten concentration profiles of 47 hydrolyzed foods (barley malt, sprouted grains, and hydrolyzed wheat proteins (HWP)) were evaluated using a multiplex-competitive ELISA that utilizes the G12, R5, 2D4, MIoBS, and Skerritt antibodies from commercial sources. Cluster analysis was conducted to evaluate similarities or differences in the gluten protein/peptide response profiles among the hydrolyzed foods and their similarities or differences with fermented foods analyzed previously by the ELISA. The gluten protein/peptide response profiles of the hydrolyzed foods mainly depended on the grain source (wheat, rye, or barley) of gluten. Some hydrolyzed foods presented profiles similar to those of certain fermented foods (e.g., barley malt and gluten reduced barley beers), whereas others presented unique profiles (e.g., HWP and sprouted wheat). Additional analysis using wheat gluten-incurred yogurts indicated that while not suitable for the barley- or rye-containing foods tested, a newly developed gluten-incurred yogurt calibrant shows promise for the possible use in the quantitation of several wheat-containing fermented and hydrolyzed foods.