Effect of frying process on furan content in foods and assessment of furan exposure of Spanish population

• We evaluate furan content in fried bread-coated frozen foods and vegetables.
• Deep frying increases furan levels in bread-coated frozen foods (up to 172 ng g−1).
• There is a furan increase tendency when reheated olive oil is used.
• Furan was found in griddled vegetables at low levels, but not in raw and fried ones.
• Furan could be a possible health risk in people with high consumption of fried foods.

Furan content in eight bread-coated frozen foods (ham croquettes, squid rings, tuna pasties, churros, nuggets, fish fingers, onion rings and san jacobos) deep-fried in fresh and reheated olive oil, and in five cooked vegetables was evaluated. Deep fried foods showed the highest levels of furan between 12 μg kg−1 (tuna pasties) and 172 μg kg−1 (onion rings), with a furan increase tendency when reheated oil was used. In vegetables, furan was only found at low level in griddled onion (3.5 μg kg−1). The lower temperature applied (<150 °C) in comparison to that of the deep-fried foods (190 °C), the furan volatilization during longer time cooking (15 min vs 6 min) together with the food composition differences might explain the low furan content in vegetables. As a preliminary approach for risk assessment, the margin of exposure (MOE) was calculated. The total daily intake of furan by Spanish population (239–4372 ng/kg bw/day) with MOEs below 10,000 indicates a human public health concern. However, MOEs for fried foods showed that furan could suppose a possible health risk only in people with a high consumption of these products. Nevertheless, further studies should be developed to provide furan exposure data of other fried foods.