This edition of the Red Folder comes from the kitchen.

Cooking with infrared light is becoming increasingly popular because it can cook some foods quickly and evenly – often using less energy than more conventional techniques. Now, Majid Javanmard and colleagues at the Iranian Research Organization for Science & Technology have taken a close look at popcorn that was popped using infrared light.

In “Continuous Infrared Popping: Effect on Key Physicochemical Attributes of Popcorn”, the trio look at the popping properties and energy consumption of an infrared system as well as the “sensory properties” and colour of the popcorn. For their study, the researchers created an infrared popping system with a rotating chamber that held corn kernels close to two infrared lamps. The team used three different power levels (600, 700 and 800 W) and found that the 700 W popcorn was superior. The researchers conclude that their infrared system can make tasty popcorn in a more energy-efficient way than traditional methods.

Shock waves

Researchers in Germany have calculated that washing dishes using super-heated steam is more effective and more environmentally friendly than conventional dishwashers. Natalie Germann at the University of Dortmund and Laila Abu-Farah at the Technical University of Munich did simulations which suggested that the technique could kill 99% of bacteria on a plate in just 25 s. What is more, the duo says that the shock waves created as the high-velocity steam is reflected off the internal surfaces of a dishwasher would be very good at removing food from dishes.

“Our study helps determine the strength of the shocks, the position of the shocks and the vortices that are created inside the dishwasher,” says Abu-Farah. “These things are very important for arranging the items or objects inside the dishwasher, and the placement and orientation of the nozzles.”

Although a super-heated dishwasher would cost more than a conventional unit, the researchers say that users would benefit from using less water, detergent and electricity. They also point out that the high level of hygiene achieved by super-heated steam would be attractive to commercial users such as restaurants and hospitals.

The research is described in Physics of Fluids.