People love fried foods, but they often contain a lot of fat. Too much fat can lead to weight gain and high blood pressure. Making lower‑fat versions that still taste good could help us eat healthier without missing out on flavor.
How Microwave Frying Works
Researchers at the University of Illinois Urbana‑Champaign studied a new way to make french fries. They mixed regular hot‑oil frying with microwave heating. The microwaves heat the potato from the inside, creating steam that pushes oil out of the fries.
Professor Pawan Singh Takhar explained, “We want fries that have less oil but still feel crunchy and tasty.” Together with doctoral student Yash Shah, the team ran two experiments to see how microwaves change the cooking process.
What Happens Inside a Fry
First, potatoes are peeled, cut into strips, blanched, and salted. They are then fried in soybean oil at 180 °C. During frying the scientists measured temperature, pressure, texture, moisture and oil content.
When a fry is first placed in hot oil, its tiny pores are full of water. Because there is no empty space, oil cannot get in. As the water evaporates, tiny holes appear and negative pressure pulls oil inside—much like sucking through a straw.
Microwaves Reduce Oil Uptake
Most of the oil‑drawing stage happens under negative pressure. Microwaves flip this by heating water molecules everywhere inside the fry. This creates more steam, raises internal pressure, and keeps oil from being absorbed.
In short, microwaves make the inside of the fry push oil away, while the hot oil on the surface still gives the fry a golden crust.
Faster Cooking, Less Oil
The team built math models to predict how temperature, pressure, moisture and oil change with different microwave frequencies (2.45 GHz and 5.8 GHz) and with regular frying.
Results showed three benefits:
- Moisture leaves the fry more quickly.
- Cooking time is shorter.
- Overall oil absorption drops.
Using only a microwave, however, makes the fries soggy. The researchers therefore suggest a combined unit: traditional heating for crispness and microwaves for low oil.
Practical Use for Food Factories
Existing industrial fryers could be upgraded with inexpensive microwave generators. This makes the dual‑heat method realistic for large‑scale production.
The studies were published in the Journal of Food Science and Current Research in Food Science. Funding came from the USDA National Institute of Food and Agriculture.