A Highly Sensitive Method for the Detection of Hydrolyzed Gluten in Beer Samples Using LFIA

Abstract

Most gluten analysis methods have been developed to detect intact gluten, but they have shown limitations in certain foods and beverages in which gluten proteins are hydrolyzed. Methods based on G12/A1 moAbs detect the sequences of gluten immunogenic peptides (GIP), which are the main contributors to the immune response of celiac disease (CD). Immunogenic sequences with tandem epitopes for G12/A1 have been found in beers with <20 mg/kg gluten, which could be consumed by CD patients according to the Codex Alimentarius. Therefore, an accurate method for the estimation of the immunogenicity of a beer is to use two moAbs that can recognize celiac T cell epitopes comprising most of the immunogenic response. Here, a specific and sensitive method based on G12/A1 LFIA was developed to detect GIP in beers labeled gluten-free or with low gluten content, with an LOD of 0.5 mg/kg. A total of 107 beers were analyzed, of those 6.5% showed levels higher than 20 mg/kg gluten and 29% showed levels above the LOD. In addition, G12/A1 LFIA detected gluten in 15 more beer samples than competitive ELISA with another antibody. Despite their labeling, these beers contained GIP which may cause symptoms and/or intestinal damage in CD patients.

Characteristics and Immunogenicity of Gluten Peptides in Enzyme-Treated and -Untreated Beers for Celiac Patients

“…The use of MS, untargeted and certainly targeted, is not at all obvious due to the need for complex instruments, expensive equipment, high operating costs and specialised personnel, as well as due to the complexity of the beer sample containing many different peptides [45]. The developed method by Segura et al [22] based on G12/A1 LFIA offers good opportunities to measure the low gluten-immunogenic peptide level in gluten-free beers. Mass spectrometric analysis may then become redundant.…”

“…A highly sensitive and easy-to-use method based on G12/A1 monoclonal antibody lateral flow immunochromatographic assay (LFIA) was developed by Segura et al [22] (2022) that requires no extraction and has an LOD of 0.5 ppm gluten. In addition, the method can measure the level of bioavailable gluten-immunogenic peptides in hydrolysed foods.…”

“…In addition, the method can measure the level of bioavailable gluten-immunogenic peptides in hydrolysed foods. Their results showed that, although regulations allow beer products to contain less than 20 ppm of gluten to be considered gluten-free, they still contain gluten-immunogenic peptides, which should not be consumed by patients with CD [22].…”

Comprehensive Epitope Analysis of Monoclonal Antibodies Binding to Hen Egg Ovalbumin Using a Peptide Array

“…Enzymelinked immunosorbent assay (ELISA), being recognized as a powerful tool, is considered the gold standard in many countries, including the aforementioned ones, for food allergen detection [5,7,8]. Lateral flow immunoassay (LFI) is widely employed as a simple allergen detection method [9,10]. It is extremely useful for quality control in food production sites as it enables quick and easy visualization of allergen test results without requiring expensive equipment.…”