The food we eat determines how we feel, and of course, nothing beats a good toast, even in moderation. As they prepare for missions to the Moon and Mars, astronauts will be happy to hear from researchers that there is a basic comfort food that is inaccessible even in space: french fries.

ESA supports research into microgravity roasting techniques to fill knowledge gaps on Earth and in space. Potatoes are fried all over the world, but involve complex physics and chemistry, and things get even more complicated in space. There was no certainty that the roast would work without gravity. Without the buoyancy to pull them up, the bubbles can cling to the potato’s surface and trap the potato in a layer of steam, which, the researchers say, can leave it undercooked and undesirable.

“Ask any chef and they will confirm that the physics and chemistry behind food is a complex and fascinating subject that extends to other scientific disciplines,” says Professor Todoris Karapantsios of the Aristotle University of Thessaloniki, a member of the research team. group. . The article was published in the journal International Food Research .

parabolic spring

To examine how microgravity affects cooking techniques such as frying, a new safe, zero-gravity carousel-type experimental device was developed. Experiments were performed on two ESA parabolic flights in which the aircraft flew in repetitive arcs to recreate brief moments of weightlessness.

The experiment filmed the frying process using a high-speed, high-resolution camera to capture bubble dynamics such as growth rate, size and distribution, as well as exit velocity, bubble velocity, and direction of movement towards the oil. The experiment measured the temperature of the boiling oil, as well as the temperature inside the potato.

Experimental equipment is automated and sealed for safety. It maintains a constant pressure in the frying chamber to prevent leaks, prevent oil spillage and consume less energy for heating.

French fries on Mars

Researchers at the University of Thessaloniki, Greece, found that shortly after the potatoes were added to the oil in low gravity, steam bubbles easily left the surface of the potatoes, just as on Earth. While more research is needed to fine-tune some parameters, this suggests that astronauts may be eating more of the diluted food on the menu when they explore new worlds.

“In addition to nutrients and convenience, studying the process of roasting in space could lead to advances in areas ranging from conventional boiling to solar hydrogen production in microgravity,” said team member John Liumbas. Source