Food production and service practices to reduce gluten exposure in celiac disease

Abstract

Consumer demand for gluten-free foods continues to rise, driven in part by the increasing prevalence of celiac disease (CD) and other gluten-related disorders, which collectively affect between 1–13% of the population. CD is an autoimmune disorder triggered by dietary gluten, and the only known treatment is strict, lifelong exclusion of gluten from the diet. Although the popularity of gluten-free products has expanded their availability, regulatory oversight surrounding their production remains limited. A major concern is gluten cross-contact, the unintended transfer of gluten to gluten-free products during food preparation or handling, which poses a risk of contamination in retail and foodservice establishments. Current international labeling standards, as defined by the WHO/FAO Codex Alimentarius Commission, specify that foods labeled "gluten-free" must contain less than 20 parts per million (ppm) of gluten. However, some individuals with CD may react to levels below this threshold, and compliance with these standards is largely voluntary. While the Codex endorses the use of the R5 enzyme-linked immunosorbent assay (ELISA) for gluten quantification, testing is not mandated and is left to the manufacturer's discretion. This creates inconsistencies in compliance and consumer protection. Certifying agencies such as the National Celiac Organization provide testing requirements and often enforce stricter gluten thresholds, but these certifications are also optional. In the US, the Food and Drug Administration (FDA) adopted the Codex rule for gluten-free labeling in 2013. Supplemental guidance is provided by the Food Allergen Labeling and Consumer Protection Act (FALCPA) and the Food Safety Preventive Controls Alliance (FSPCA), which support manufacturers in implementing safe allergen-handling practices. However, these guidelines primarily apply to packaged goods. For unpackaged foods, the FDA's Food Code provides definitions and recommendations for gluten-free labeling and encourages retail establishments to adopt preventive measures to minimize cross-contact risk. Despite these resources, education and training gaps remain, particularly among small-scale and artisanal bakers. In Colorado, many of these producers lack comprehensive understanding of gluten as immunostimulatory protein, celiac disease, and the risks of cross-contact during food production. To address this gap, the present study investigated production practices and potential gluten contamination in gluten-free baked goods sourced cafes, bakeries, and restaurants across Colorado's Front Range. Establishments were observed for adherence to safe food handling practices, and gluten content was measured using the RIDASCREEN® Gliadin ELISA and absorbance was quantified via UV-Vis spectrophotometry. Establishments visited include cafés, bakeries, and restaurants. More than half of the samples were served from shared storage cases, and although five samples contained gluten, all fell below the limit of 20 ppm. Notably, three originated from facilities where food debris on surfaces and inconsistent handling practices were observed. The absence of standardized protocols and testing requirements presents an ongoing challenge for consumers seeking assurance that products labeled "gluten-free" are truly safe for consumption. Therefore, this thesis provides (1) an overview of gluten as an immunostimulatory protein, (2) a discussion of CD pathogenesis and its distinction from other gluten sensitivities, (3) a review of current and emerging treatment approaches, (4) an outline of existing regulations governing gluten-free labeling and production, and (5) strategies to improve cross-contact prevention and consumer protection in retail establishments. The specific objective of this study was to evaluate the frequency of gluten cross-contact in artisanal gluten-free baked goods produced along Colorado's Front Range. We hypothesized that a subset of the marketed gluten-free baked goods purchased from producers across Colorado's Front Range would test positive for gluten concentrations exceeding the legal limit of 20 ppm. We further expected that cross-contact would be associated with environmental observations related to food handling practices (such as mode of delivery, employee hygiene, shared storage spaces, etc.).