Are French fries a risk to celiac consumers? A study in burger restaurants from Goiânia/Brazil

This study assessed the occurrence of gluten cross-contamination in French fries produced in burger restaurants where fried breaded-products are also handled. This cross-sectional exploratory quantitative study was conducted in five steps: (i) identification of burger restaurants selling French fries and gluten-containing foods; (ii) acquisition of French fries' samples; (iii) questionnaire application regarding: the number of fried foods sold in addition to French fries, sharing the same oil for frying French fries and other breaded products, sharing the same fryer basket for frying French fries and other breaded products, and the frequency of oil change; (iv) sample processing and analysis of gluten in the samples; (v) data statistical analysis. 81 French fries’ samples were analyzed and 4.9% (n = 4) presented gluten contamination above 20 ppm. Regarding the variables of interest, such as the quantity of fried foods sold in addition to French fries, sharing the same oil for frying French fries and other breaded products, sharing the same fryer basket for frying French fries and other breaded products, and the frequency of oil change, there were no statistically significant associations. Further studies are necessary to assess other scenarios concerning contamination risks due to other commonly used cooking procedures. • 4.9% of French fries from burger places presented gluten above 20 ppm. • 4.9% of French fries presented gluten between 5.32 and 12.96 ppm. • Number of gluten-fried products was not associated with gluten contamination. • Sharing oil was not associated with gluten contamination. • No significant associations between gluten contamination and frequency of oil change.