New microwave frying method could make french fries much healthier | ScienceDaily

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New microwave frying method could make french fries much healthier

Date:<br>July 29, 2026<br>Source:<br>University of Illinois College of Agricultural, Consumer and Environmental Sciences<br>Summary:<br>A new cooking method could make French fries crispier in less time while significantly limiting how much oil they absorb. Researchers propose combining microwave heating, which keeps oil out, with conventional frying, which provides the crunch consumers expect.<br>Share:

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A microwave-assisted frying method could produce faster-cooking French fries with less oil and plenty of crunch. Credit: Shutterstock

French fries and other fried foods are popular largely because of their crisp texture and rich flavor. However, they can absorb large amounts of oil during cooking, increasing their fat and calorie content. Regularly consuming foods high in fat can contribute to health problems such as obesity and hypertension.

Researchers at the University of Illinois Urbana-Champaign are investigating whether microwave energy could help produce French fries that absorb less oil without losing the qualities consumers expect. Their findings suggest that combining microwave frying with conventional frying could shorten cooking time, limit oil uptake, and still create the crisp exterior and satisfying texture associated with traditional fries.

Creating Healthier Fries Without Sacrificing Flavor

"Consumers want healthy foods, but at the time of purchase, their cravings often take over. High oil content adds flavor, but it also contains a lot of energy and calories. My research team studies frying with the aim of obtaining lower fat content without significant differences in taste and texture," said principal investigator Pawan Singh Takhar, professor of food engineering in the Department of Food Science and Human Nutrition, part of the College of Agricultural, Consumer and Environmental Sciences at U of I.

Takhar and Yash Shah, a doctoral student in FSHN, reported their results in two new publications examining the physical changes that occur when French fries are cooked with microwave energy.

For the first study, the Illinois researchers worked with scientists at Washington State University who had developed a specialized microwave fryer. The device could operate at both 2.45 gigahertz (similar to a regular microwave oven) and 5.8 gigahertz.

Gigahertz is a unit used to describe the frequency of electromagnetic waves. Different microwave frequencies can affect how energy moves through food and how quickly water molecules respond during cooking.

Tracking What Happens Inside a French Fry

The researchers rinsed and peeled potatoes before cutting them into strips. The strips were then blanched, salted, and fried in soybean oil that had been heated to 180 degrees Celsius.

Blanching briefly exposes food to hot water or steam. For potatoes, this step can begin softening the tissue and help prepare the surface for frying.

During and after cooking, the team measured temperature, internal pressure, volume, texture, moisture, and oil content. These measurements helped reveal how water escaped from the potatoes and how oil entered the spaces it left behind.

According to Takhar, one of the central challenges in frying is preventing oil from moving into food both during cooking and immediately afterward.

At the start of frying, the tiny pores inside a potato are still filled with water, leaving little room for oil. As the potato heats up, however, that water turns into vapor and escapes. Empty spaces begin to form, and negative pressure can pull oil into the potato.

"Think about a straw in a drink. If you push air into the straw, it creates positive pressure and any liquid will be pushed out. But if you suck on the straw, the liquid moves upward. Now imagine food materials have lots of tiny straws. When there is positive pressure, the oil stays out. But if there is negative pressure, the oil starts moving in," Takhar explained.

Why Pressure Determines Oil Absorption

The researchers found that as much as 90% of frying occurs while the food is under negative pressure. That creates a prolonged suction effect, allowing oil to move into the newly opened pores.

A more effective frying process would keep pressure inside the potato positive for a longer period and reduce the amount of time spent under negative pressure. This could limit the amount of oil drawn into the food.

Microwave energy may help by heating water throughout the potato rather than relying only on heat moving inward from the surface. As water molecules absorb microwave energy, they move more rapidly and generate additional vapor. That vapor raises the pressure inside the food and makes it harder for oil to enter.

"When we heat something in a conventional oven, the heat moves from outside to inside,...