Detection of gluten content in both naturally and labelled gluten-free products available in Morocco

Patients with celiac disease have to rely on the safety of gluten-free foods (GFF), which are frequently contaminated by gluten. Hence, the evaluation of the gluten level in these foods is important. The aim of this study was to assess the gluten content in GFF available in Morocco. It was carried out on 84 food samples including 52 labelled gluten-free foods (L-GFF) and 32 naturally gluten-free foods (N-GFF), belonging to six categories (pasta, cookies and cakes, baker's yeast, dried vegetables, dried fruits, and cereals). To quantify their gluten content, samples were analysed using a sandwich enzyme immunosorbent assay (R5 ELISA Ridascreen ® gliadin Mendez), considering 20 mg/kg (ppm) as the contamination threshold. The overall contamination rate was 23.8% (L-GFF: 21.9%, N-GFF: 25%). Among the six analysed categories, three did not show any contamination (pasta, cookies, and baker's yeast). The contamination rate was 5.3% in dried vegetables, 25% in dried fruits, and 42.1% in cereals. All oat samples were affected. L-GFF locally manufactured were more often contaminated than those imported (28.6 vs. 16.7%). Our data show a high prevalence of gluten contamination of GFF, affecting both N-GFF and L-GFF, and oats were the most contaminated food. Therefore, regular checks of GFF by the competent authorities are necessary in order to avoid the sale of unsafe GFF for celiac patients. Likewise, manufacturers should be encouraged to adopt adequate quality management systems.