New Microwave Frying Method Reduces Oil in French Fries

A new cooking method could make French fries crispier in less time while significantly limiting oil absorption. Researchers propose combining microwave heating with conventional frying. This method aims to reduce fat and calorie content in fried foods. High oil content contributes to health problems like obesity and hypertension.

Researchers at the University of Illinois Urbana-Champaign investigated microwave energy's role in reducing oil absorption. Their findings suggest that combining microwave frying with conventional frying shortens cooking time. It also limits oil uptake while maintaining the desired crisp exterior and texture. The research team studies frying to achieve lower fat content without sacrificing taste and texture.

The team conducted two studies on the physical changes in French fries cooked with microwave energy. They worked with scientists at Washington State University who developed a specialized microwave fryer. This device operates at 2.45 gigahertz and 5.8 gigahertz. Gigahertz describes the frequency of electromagnetic waves. Different frequencies affect how energy moves through food and how quickly water molecules respond during cooking.

Potatoes were blanched, salted, and fried in soybean oil heated to 180 degrees Celsius. Blanching softens the tissue and prepares the surface for frying. During and after cooking, the team measured temperature, internal pressure, volume, texture, moisture, and oil content. These measurements revealed how water escaped and how oil entered the empty spaces.

Microwave energy heats water throughout the potato, generating additional vapor. This vapor raises the internal pressure, making it harder for oil to enter. Microwave frying alone resulted in soft fries, lacking the desired crispness. The proposed system combines conventional frying for crispness with microwave energy to reduce oil intake. This hybrid approach could allow manufacturers to produce fries with less oil while preserving flavor and texture. Faster cooking could also improve production efficiency. Continuous fryers in food processing facilities could be modified to include microwave generators. These components are widely available and relatively inexpensive.