The perfect breakfast egg with fluid mechanics

A research team from the University of Naples has published a new method for the optimal preparation of eggs that cooks both the yolk and the egg white evenly. This “periodic cooking” is said to produce eggs with a higher nutrient content than conventional cooking methods. The egg is switched back and forth between a pot of hot water and one of cold water. The team published their results in the journal “Communications Engineering”.

Conventional methods of cooking eggs often have the problem that either the yolk or the egg white is not cooked optimally. While the egg white coagulates completely at 85 degrees Celsius, the yolk only needs 65 degrees Celsius. The innovative cooking technique developed by the team led by Pellegrino Musto and Ernesto Di Maio makes it possible to cook both parts of the egg simultaneously at their optimum temperatures without separating them.

They found their method by first simulating the process in computational fluid dynamics software. The simulations suggested alternately placing the egg in a pot of boiling water at 100 degrees Celsius and in a bowl at 30 degrees Celsius, alternating every two minutes for a total of 32 minutes. They call their method “periodic cooking”.

Between soft and sous-vide

In initial tests, the egg yolk retained a creamy consistency similar to that of sous-vide eggs, while the egg white had a texture between sous-vide and soft-boiled. Sous-vide refers to the method of cooking eggs for a long time at a low temperature, approximately between 60 and 70 degrees Celsius, for up to an hour. The temperatures in the egg white of the periodically cooked egg fluctuated between 35 and 100 degrees Celsius during cooking, while the yolk had a constant temperature of 67 degrees Celsius.

The researchers then examined the texture and sensory qualities of the fully cooked eggs. They evaluated their chemical properties using nuclear magnetic resonance and high-resolution mass spectrometry. The chemical analysis revealed that the yolk of the periodically boiled eggs had a higher content of polyphenols, which are known for their health-promoting properties. These nutrients could help to improve the egg dish not only in terms of taste, but also nutritionally.

In addition, this novel cooking method could also have applications outside the kitchen. The researchers suspect that the principle of periodic cooking could be useful in material processing, for example in the hardening and crystallization of materials.

(mack)