Precautionary allergen labeling (PAL) is widely used by food industries. Occurrence studies revealed that few analyzed products contained the allergen(s) present in the statement, but little is known in Canada. To improve manufacturing practices and better manage allergen cross-contamination, occurrence data is needed to determine the exposure of allergic individuals eating those products. Samples were analyzed for peanuts (n = 871) and hazelnuts (n = 863) using ELISA methods. Within samples analyzed for peanuts, 72% had a PAL (n = 628), 1% had peanuts as a minor ingredient (n = 9) and 27% were claimed “peanut-free” (n = 234). Most hazelnut samples had a PAL for tree nuts/hazelnuts (94%; n = 807) with 6% claimed “nut-free” (n = 56). Peanuts and hazelnuts were found in 4% (0.6–28.1 ppm) and 9% (0.4–2167 ppm) of all samples, respectively. Chocolates were mostly impacted; they should be treated apart from other foods and used in risk assessments scenarios to improve manufacturing practices, reducing unnecessary PAL use.

Gluten has a central role in the pathogenesis of several gluten-related disorders, with coeliac disease being one of the most well-known. A rigorous gluten-free diet is recognized as the only safe and efficient coeliac disease therapy. This study intended to use the enzyme-linked immunosorbent assay (ELISA) R5 Méndez method to determine gluten contamination in labelled gluten-free food products marketed in China and to evaluate the performance of two ELISA platforms (the Neogen Veratox^® R5 and the Romer Labs AgraQuant^® G12) for analyzing gluten, using R5 Méndez as the reference. In 2024, 119 prepackaged products labelled as gluten-free were purchased from internet suppliers. The results showed that among the 119 products, 13.4% contained gluten exceeding 20 mg/kg, and 5.0% contained over 100 mg/kg, ranging from 333.1 to 2737.4 mg/kg. When the threshold for gluten-free products was 20 mg/kg, the two ELISA platforms yielded results comparable to R5 Méndez. However, when the threshold was 10 mg/kg and 5 mg/kg, the McNemar x² test showed significant differences between the proportions of positive results of the two ELISA platforms and R5 Méndez (p-value < 0.05); using R5 Méndez as the reference, the two ELISA platforms showed 53.1% to 70.3% positive predictive values, suffering the drawback of high false-positive results. When using stricter gluten limits of ≤10 mg/kg and ≤5 mg/kg, different ELISA platforms may produce different results for the same food product. These findings highlight the need for China to accelerate the development of national standards for gluten-free foods, and for food regulatory agencies to impose requirements of production that lead to the prevention of gluten contamination, confirmed by the possible monitoring of such compliance through routine sampling and testing. Such measures will no doubt contribute to protecting and improving the health of patients with gluten-related disorders.

Celiac disease (CD) is triggered by ingestion of gluten-containing cereals such as wheat, barley, rye and in some cases oat. The only way for affected individuals to avoid symptoms of this condition is to adopt a gluten-free diet. Thus, gluten-free foodstuffs need to be monitored in order to ensure their innocuity. For this purpose, commercial immunoassays based on recognition of defined linear gluten sequences are currently used. These immunoassays are designed to detect or quantify total gluten regardless of the cereal, and often result in over or underestimation of the exact gluten content. In addition, Canadian regulations require a declaration of the source of gluten on the label of prepackaged foods, which cannot be done due to the limitations of existing methods. In this study, the development of new antibodies targeting discrimination of gluten sources was conducted using synthetic peptides as immunization strategy. Fourteen synthetic peptides selected from unique linear amino acid sequences of gluten were bioconjugated to Concholepas concholepas hemocyanin (CCH) as protein carrier, to elicit antibodies in rabbit. The resulting polyclonal antibodies (pAbs) successfully discriminated wheat, barley and oat prolamins during indirect ELISA assessments. pAbs raised against rye synthetic peptides cross-reacted evenly with wheat and rye prolamins but could still be useful to successfully discriminate gluten sources in combination with the other pAbs. Discrimination of gluten sources can be further refined and enhanced by raising monoclonal antibodies using a similar immunization strategy. A methodology capable of discriminating gluten sources, such as the one proposed in this study, could facilitate compliance with Canadian regulations on this matter. This type of discrimination could also complement current immunoassays by settling the issue of over and underestimation of gluten content, thus improving the safety of food intended to CD and wheat-allergic patients.

Background: Food-allergic reactions in restaurants often result from miscommunication between customers with allergies and staff, or from staff members’ insufficient knowledge of food allergies. This study examined the behaviors, attitudes, and risk perceptions of food-allergic consumers when dining out or ordering from foodservice establishments (FSEs) compared to consumers without food allergies. Methods: A representative pan-Canadian survey was conducted amongst three groups: one of individuals without food allergies (n = 500) and two of food-allergic individuals (allergic-convenience sample [n = 500] and allergic-general population [n = 500]). The convenience sample comprised members of Food Allergy Canada, a national patient advocacy organization. Some participants with food allergies had experienced reactions linked to an FSE (43% convenience, 27% general). Weighted responses from food-allergic groups were compared to those of non-allergic ones using chi-square (p < 0.05). Statistical comparison between allergic groups was not attempted due to inherent differences in their allergic condition. Results: In several questions, responses from the non-allergic group differed significantly from those of the allergic-convenience sample, but not from those of the allergic-general population. Food-allergic-convenience respondents were more likely to avoid ordering food or dining out than non-allergic ones, with the highest avoidance (66%) noted for third-party platforms. Cost was the main barrier for non-allergic and allergic-general populations, whereas the allergic-convenience sample prioritized allergy-related concerns. Although at a lower rate than for participants with food allergies, food allergies influenced restaurant selection for 44% of participants without food allergies when dining with individuals outside their household. Most allergic respondents perceived that FSEs underestimate the seriousness of food allergies (82% convenience, 71% general), yet they felt safe while dining out (60% convenience, 85% general), pointing at loyalty to specific FSEs as a risk mitigation strategy. Conclusions: This study highlights a potentially higher burden of disease (psychological and social strain, reduced quality of life) among a subgroup of the food-allergic population (convenience sample), as reflected in their behaviors, attitudes, and risk perceptions towards meals prepared in FSEs. Nevertheless, both allergic groups expressed shared concerns and needs related to safety (e.g., ingredient disclosure for all menu items, prevention of allergen cross-contact, ability of an FSE to offer a safe meal, establishing clear communication processes for allergy-related information), which FSEs and regulators should consider when designing risk management strategies.