Analyzing Gluten Content in Various Food Products Using Different Types of ELISA Test Kits

Abstract

Gluten is an insoluble protein produced when glutelins and prolamins, which are found in grains such as wheat, barley, and oats, combine to form an elastic thin film. This dietary gluten can cause severe contraction of the intestinal mucous membrane in some people, preventing nutrient absorption. This condition, called celiac disease (CD), affects approximately 1% of the world’s population. The only current treatment for patients with CD and similar diseases is lifelong avoidance of gluten. To analyze the gluten content in food, various enzyme-linked immunosorbent assay (ELISA) tests are currently used. In this study, the gluten content in various food products was analyzed using different kinds of ELISA test kits. For gluten-free food, three different ELISA test kits mostly yielded values below the limit of detection. However, gluten was detected at 24.0–40.2 g/kg in bread, 6.5–72.6 g/kg in noodles, and 23.0–86.9 g/kg in different powder food samples. A significant difference (p < 0.05) in gluten content was observed for these gluten-containing food products. Reproducibility issues suggest that it is necessary to use several ELISA kits for the accurate detection and quantification of gluten in various food products rather than using one ELISA kit.

Challenges in Gluten Analysis: A Comparison of Four Commercial Sandwich ELISA Kits

“…The higher gluten levels obtained by the R-Biopharm AG kit in those nine samples are, in part, possibly the consequence of the pretreatment with the cocktail solution containing a protein unfolding agent and a protein disaggregating agent prior to the ethanol extraction ( Table 1 ). Similar to our finding, in a three-subsampling analysis of high gluten-containing commercial samples by Yu et al [ 41 ], the R-Biopharm AG kit yielded higher results when compared to the Neogen kit, nearly two times higher for two wheat flours and 3.9, 4.6, and 5.6 times higher for instant noodle, udon, and spaghetti, respectively. Apart from the three kits, the Morinaga kit yielded comparable wheat protein contents in the samples of rye, triticale, barley, spelt, common wheat, all the tetraploid wheats, and the crude wheat protein ( Table 3 ).…”

Twin-Screw Extrusion as Hydrothermal Technology for the Development of Gluten-Free Teff Flours: Effect on Antioxidant, Glycaemic Index and Techno-Functional Properties

“…Celiac disease affects 1:100–1:200 worldwide, although many remain undiagnosed. It is caused by intolerance to gluten, a protein that is present in wheat, barley, rye and some varieties of oats, as well as their hybrids [ 1 ].…”

Patterning Large-Scale Nanostructured Microarrays on Coverslip for Sensitive Plasmonic Detection of Aqueous Gliadin Traces

“…Consequently, the development of rapid and sensitive methods for the detection of gluten in such products is crucial to assure consumer safety [11,12]. For instance, the immunological techniques based on Enzyme Linked Immunosorbent Assays (ELISA) are often used for the optical detection of large variety of (bio)analytes [13,14]. In the case of gluten screening, an official method approved by AOAC (Association of Official Agricultural Chemistry) using anti ω-gliadin antibodies in a sandwich format is reported [15].…”