Survey on the occurrence of allergens on food-contact surfaces from school canteen kitchens

According to Regulation (EU) 1169/2011, restaurants and catering services have to manage the risk of food allergens in the products they offer. One of the sources of hidden allergens in food could come from the cross-contact with surfaces or utensils. In order to gain knowledge about the current situation in such kind of establishments, the occurrence of 3 main allergen residues (milk, egg and gluten) has been evaluated in food-contact surfaces from 50 school canteens during a period of two academic years (2014-2016). The study included not only food-contact surfaces of general use but also surfaces for exclusive use in meals free of specific allergens. These food-contact surfaces were selected and analyzed in situ by using a rapid LFIA test during the visits to kitchens. Leftover sample was sent to a laboratory where an ELISA test was performed to confirm results. Out of 621 analyzed surfaces (213 samples for milk and egg and 195 samples for gluten) none of them were found to content milk with the rapid tests. However, the presence of egg and gluten was detected in 15 and 45% of the food-contact surfaces, respectively. The results obtained with ELISA showed also a low occurrence for milk (6%) but higher for egg (24%) and gluten (57%). It has to be highlighted that for some specific food-contact surfaces the occurrence reached up to 40%. These results indicate that the current cleaning procedures as well as the subsequent manipulation of surfaces are not enough suitable for the control of allergen residues in canteens. Besides, the presence of allergens in food-contact surfaces of exclusive-use to prepare allergen-free meals implies that cross-contaminations might happen, thus increasing the risk of hidden allergens in the final product.