Any Way You Fry It: University Of Arkansas Researchers Receive Grant To Study Acrylamide Presence In Fried Foods

FAYETTEVILLE, Ark. — No one ever claimed French fries, donuts or potato chips as health food, but recent studies have shown that the spuds and other fried foods may contain worrisome concentrations of the neurotoxin acrylamide. A team of University of Arkansas researchers has received a grant to study methods for detecting and quantifying acrylamide in foods. They also will design experiments that optimize frying processes to minimize acrylamide formation.

Andy Proctor, professor of food science, Jean-Francois Meullenet, associate professor of food science and Jack Lay, director of the Statewide Mass Spectrometry Facility, have received $150,000 from the Arkansas Biosciences Institute for acrylamide research. J.A. Hinson, director of the division of toxicology for the University of Arkansas for Medical Sciences, will also contribute to this investigation.

First, they will use liquid chromatography/mass spectrometry techniques to determine the acrylamide content of certain common fried foods in Arkansas. Liquid chromatography separates out different chemicals in a solution and delivers them to the mass spectrometer for analysis, one at a time. These chemicals can then be identified and quantified through mass spectrometry techniques to the parts-per-billion level.

The researchers will start by "spiking" solutions with known amounts of acrylamide and detecting them using the mass spectrometry techniques. The signal for the known amount of isotopic-tagged acrylamide will be compared to the signal for the "natural" acrylamide. Since a known amount of tagged acrylamide was added to the sample, the relative signals give the starting amount of "natural" acrylamide present in the sample, even if some was lost in the process of analysis. This technique of "isotope dilution" mass spectrometry is the gold standard method for quantitative analysis at these low levels.

They will compile the resulting acrylamide levels for the food products and post them on the Web as a public service, Meullenet said.

Past research has shown that acrylamide levels vary widely, but can reach as high as 680 micrograms/kilogram in a serving of French fries and 1,544 micrograms/kilogram in a serving of potato chips. The World Health Organization recommends that acrylamide intake in water not exceed 1 microgram a day.

Based on these findings, in 2002 the World Health Organization called for research to quantify acrylamide levels in foods and to determine the effect of the neurotoxin on human health. At the same time the U.S. Food and Drug Administration declared its intent to fund studies to evaluate acrylamide levels in various foods. The current debate about acrylamide has brought the neurotoxin into the public view, but initial reports about acrylamide content in food continue to vary. Certain brands of corn chips contained substantial amounts of acrylamide, while others contained little. And some cereals and taco shells contain the neurotoxin as well.

The complex chemnistry of frying has many variables that could affect acrylamide formation, Proctor said. The frying temperature, the type of oil used, the amount of time spent frying, the object being fried, even the food product surface may impact acrylamide formation.

Acrylamide forms during a process called the Maillard reaction, which also creates the flavor and color that make fried foods so delectable. The amino acid asparagine, found abundantly in potatoes and major cereals, participates in acrylamide formation.

The researchers will work backwards through the frying process, using a model system involving filter papers containing different concentrations of amino acids and sugars. They will use the model system to understand what variables-time, temperature, oil quality or food product surface-may impact acrylamide formation. From these results, they will design a frying experiment using actual food to try to minimize acrylamide while maintaining flavor and texture.

Current acrylamide detection relies on expensive research grade mass spectrometry equipment, but Lay will use a relatively inexpensive mass spectrometer and design a novel method to detect acrylamide formation with a spectrometer more easily integrated into food research. The researchers hope to disseminate their mass spectrometry technique to the food industry so it can be used to screen for this neurotoxin on a wider basis.

"It will be a good tool to use to understand cooking processes on small and large scales," Lay said.

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