Nickel levels in convenience and fast foods: In vitro study of the dialyzable fraction

Nickel presence was determined in 170 samples of 43 different convenience and fast foods widely consumed in Spain. Electrothermal atomic absorption spectrometry was used as analytical technique. Reliability of the procedure was checked. Ni levels ranged from 18.50 to 95.00 ng g− 1 (fresh weight of edible portion). The most elevated Ni concentrations were found in egg- and pork-based foods and in sauces but there is a high variability inside of each one of these foods. Ni content increases in products that contain spices and aromatic herbs, whole cereals, dry fruits, cheese and mushrooms. Mean Ni dialyzable fraction estimated by in vitro assays ranged from 4.50 to 7.75%. This study shows that the probability of exposure to health risks from these foods is overall small. However, the present findings are of potential use in food composition tables and to estimate the Ni dietary intake and tolerable intake levels in accordance with the current dietary habits.

Research highlights
► Ni levels in convenience and fast food range from 18.50 to 95.00 ng/g.
► Ni content increases in products that contain spices and aromatic herbs, whole cereals, dry fruits, cheese and mushrooms.
► Mean Ni dialyzable fraction estimated by in vitro assays ranges from 4.50 to 7.75%.
► The probability of exposure to health risks from convenience and fast food is overall small.