title: Detection and Quantification of Gluten during the Brewing and Fermentation of Beer Using Antibody-Based Technologies.
abstract: In 2013 the U.S. Food and Drug Administration (FDA) defined the term ''gluten-free'' and identified a gap in the analytical methodology for detection and quantification of gluten in foods subjected to fermentation and hydrolysis. To ascertain the ability of current enzyme-linked immunosorbent assays (ELISAs) to detect and quantify gluten in fermented and hydrolyzed products, sorghum beer was spiked in the initial phases of production with 0, 20, and 200 μg/ml wheat gluten, and samples were collected throughout the beer production process. The samples were analyzed using five sandwich ELISAs and two competitive ELISAs and by sodium dodecyl sulfate-polyacrylamide gel electrophoresis with Western analysis employing four antibodies (MIoBS, R5, G12, and Skerritt). The sensitivity of the MIoBS ELISA (0.25 ppm) enabled the reliable detection of gluten throughout the manufacturing process, including fermentation, when the initial concentration of 20 μg/ml dropped to 2 μg/ml. The R5 antibody-based and G12 antibody-based sandwich ELISAs were unable to reliably detect gluten, initially at 20 μg/ml, after the onset of production. The Skerritt antibody-based sandwich ELISA overestimated the gluten concentration in all samples. The R5 antibody-based and G12 antibody-based competitive ELISAs were less sensitive than the sandwich ELISAs and did not provide accurate results for quantifying gluten concentration. The Western analyses were able to detect gluten at less than 5 μg/ml in the samples and confirmed the results of the ELISAs. Although further research is necessary before all problems associated with detection and quantification of hydrolyzed and fermented gluten are resolved, the analytical methods recommended by the FDA for regulatory samples can detect ≥ 20 μg/ml gluten that has undergone brewing and fermentation processes associated with the manufacture of beer.
authors.affiliation: U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Regulatory Science, Division of Bioanalytical Chemistry, College Park, Maryland 20740, USA.
authors.forename: Rakhi
authors.initials: R
authors.lastname: Panda
authors.affiliation: Department of Food Science, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: Hans F
authors.initials: HF
authors.lastname: Zoerb
authors.affiliation: U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Regulatory Science, Division of Bioanalytical Chemistry, College Park, Maryland 20740, USA.
authors.forename: Chung Y
authors.initials: CY
authors.lastname: Cho
authors.affiliation: U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Food Safety, Division of Food Processing Science and Technology, Bedford Park, Illinois 60501, USA.
authors.forename: Lauren S
authors.initials: LS
authors.lastname: Jackson
authors.affiliation: U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Regulatory Science, Division of Bioanalytical Chemistry, College Park, Maryland 20740, USA. eric.garber@fda.hhs.gov.
authors.forename: Eric A E
authors.initials: EA
authors.lastname: Garber
mesh_terms: D000906:Antibodies; D001515:Beer / Q000032:analysis*; D002523:Edible Grain / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D005285:Fermentation; D005504:Food Analysis / Q000379:methods*; D005524:Food Technology / Q000379:methods*; D005983:Glutens / Q000032:analysis*; D006868:Hydrolysis; D015203:Reproducibility of Results; D045868:Sorghum / Q000737:chemistry
chemical_list: D000906:Antibodies; D005983:Glutens