Food Engineering

From the frying pan into the fryer

June 1, 2005
Are allergens an issue for fried foods? Experts discussed these and other topics at the 5th International Symposium on Deep-Fat Frying.

Richard F. Stier
Despite the latest health news about fried foods, trans fats and obesity, Americans hunger for the crispy, greasy and sometimes salty flavor of deep-fried foods, often frying up everything from vegetables to Thanksgiving turkeys.



Deep-fat frying is used throughout the world as means of cooking not only because it tastes good but also due to its efficient means of heat transfer. It cooks foods quickly-another appeal in a world often crushed for time. Yet, how healthy-and safe-is the frying process?

In Germany in the early 1970s, experts examined a number of foodservice and restaurant operations throughout the country. Their research underscored the fact that the quality of the frying oil had a direct effect on the quality of the food being fried. In response, the German Society for Fat Science (also known as DGF) organized a symposium to address the issue in 1973. During this and subsequent symposiums, the DGF considered ways by which oil quality could be determined.

At the 3rd International Symposium on Deep-Fat Frying in 2000, DGF delegates published eight recommendations for safe frying. Among them was the suggestion that two tests-one for total polar materials and one for polymeric triglycerides-be performed to evaluate frying oil. The group further concluded that there were no health concerns associated with the consumption of frying fats and oils that were not abused under normal frying conditions.

Studies on fried foods continued with Swedish scientists announcing in 2002 that many foods, including fried foods, contained acrylamides, a known mutagen. A wave of research followed, focusing on six key areas: occurrence in foods and analytical methodology; mechanism(s) of formation; methods for potential reduction/mitigation; exposure and biomarkers; toxicological and metabolic consequences; and risk communication. Scientists have determined that certain foods contain acrylamides but modification of the production process can reduce these levels. Whether or not the compound is a dietary concern is still unknown.



At the recent 5th International Symposium on Deep-Fat Frying held in San Francisco, delegates discussed the relationship between acrylamide and frying as well as the latest hot topic in frying-allergens. In some foodservice operations, multiple foods (such as shrimp, fish, potatoes and jalapeno poppers) may be fried in a single fryer. These products could include wheat, shellfish, fin fish, dairy and possibly egg, soy and even peanuts. Each of those allergens could potentially be transferred from the foods into the oil and then onto another food.

To determine the relationship between fried foods and allergens, scientists are currently researching answers to the following questions:

  • Does frying alter potential food allergens?
  • Does frying different foods that contain different potential allergens in one fryer pose a health risk?
  • Can potential allergens from fried foods be transferred to other foods?
  • Does frying in cold-pressed oils pose a potential health risk?
  • Does oil filtration or treatment remove potential allergens from the cooking oil?

Ultimately, the safety of fried foods remains to be seen. Like so many things in food processing, it is probably dependent on the type of operation, the products fried, the type of fryer and even the type of oil. Yet, these are questions that our industry must answer as the pressure to push the envelope on food safety continues.