Determination of Gluten Contamination in Foods Available on the Turkish Market via Enzyme-Linked Immunosorbent Assay (ELISA)

Abstract

Wheat, along with maize and rice, is one of the “big 3” cereal crops, and although it is a major component of many food products, it is one of the top eight food allergens listed by the Codex Alimentarius. The wheat protein gluten is responsible for several diseases including wheat allergy (WA), gluten sensitivity (GS), and celiac disease (CD). The presence of a “gluten free” label on food products specially produced for these patients facilitates the selection of safe products. To enforce food labeling regulations and quantitatively assess the potential degree of gluten contamination in gluten-free foods, standardized analytical methodologies are required. In recent years, multiple techniques for detecting gluten utilizing enzyme-linked immunosorbent assays (ELISAs), lateral flow devices/dipsticks, polymerase chain reaction, and mass spectrometry have been developed. In this study, the R-Biopharm Ridascreen® Gliadin Kit, a commercial ELISA kit, was used to assess the degree of gluten contamination, if any, in naturally gluten-free foods and foods labeled “gluten free” obtained from Izmir Province and its surroundings. In total, 71 samples (45 naturally gluten-free food samples, and 26 processed food samples labeled “gluten free”) were investigated for gluten contamination. Gluten extraction was performed with cocktail solution (patented, R-Biopharm), and contamination was analyzed quantitatively using the ELISA method based on the antigen–antibody relationship with the R-Biopharm Ridascreen® Gliadin Kit. In total, 94.37% of the samples were found to be gluten-free, 4.23% were found to be low in gluten, and 1.40% were found to be beyond the limit. In conclusion, gluten-free product manufacturers should implement comprehensive measures in the production stage to eliminate contamination risks, and individuals with celiac disease or gluten sensitivity should be vigilant when reading labels and inquiring about food preparation to manage symptoms and maintain good health.