title: Gluten contamination in foods labeled as "gluten free" in the United States.
abstract: Gluten is the main storage protein in grains and consists of gliadin and glutenin occurring in the same ratio. Persons suffering from intolerances, including celiac disease, must avoid foods containing gluten or products containing wheat, barley, and rye. Accordingly, gluten detection is of high interest for the food safety of celiac patients. This study was designed to determine the concentrations of gluten in foods labeled "gluten free" available in the United States. Seventy-eight samples labeled gluten free were collected and analyzed using a gliadin competitive enzyme-linked immunosorbent assay. The gluten content was calculated based on the assumption of the same ratio between gliadin and glutenin. Forty-eight (61.5%) of the 78 samples contained less than the limit of quantification of 10 mg/kg for gluten. In addition, 14 (17.9%) of the 78 samples labeled gluten free contained less gluten than the guidelines established by the Codex Alimentarius for gluten-free labeling (20 mg/kg). However, 16 samples (20.5%) did contain gluten levels of ≥20 mg/kg, ranging from 20.3 to 60.3 mg/kg. In particular, five of eight breakfast cereal samples showed gluten contents higher than 20 mg/kg. These results may be of concern, as gluten sensitivity is known to vary among celiac disease patients.
authors.affiliation: School of Food Science, University of Idaho, 875 Perimeter Drive MS 2312, Moscow, Idaho 83844-2312, USA.
authors.forename: Hyun Jung
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: School of Food Science, Washington State University, P.O. Box 646376, Pullman, Washington 99164-6376, USA.
authors.forename: Zach
authors.initials: Z
authors.lastname: Anderson
authors.affiliation: School of Food Science, University of Idaho, 875 Perimeter Drive MS 2312, Moscow, Idaho 83844-2312, USA. dryu@uidaho.edu.
authors.forename: Dojin
authors.initials: D
authors.lastname: Ryu
mesh_terms: D003257:Consumer Product Safety; D002523:Edible Grain; D004797:Enzyme-Linked Immunosorbent Assay; D005506:Food Contamination / Q000032:analysis*; D005515:Food Labeling; D005903:Gliadin / Q000032:analysis; D005983:Glutens / Q000032:analysis*; D001467:Hordeum; D015203:Reproducibility of Results; D014908:Triticum; D014481:United States; D014486:United States Food and Drug Administration
chemical_list: D005983:Glutens; D005903:Gliadin; C037302:glutenin