White foam is formed when egg whites dissolve when exposed to hot water.

Eggs contain a lot of protein. When the egg liquid is poured into boiling water, the vibration of water molecules will cause the protein to wrap around the water vapor, forming protein foam that floats on the water.

Extended information: There are many ways to eat eggs, including boiling, steaming, frying, stir-frying, etc.

In terms of the absorption and digestibility of egg nutrients, boiled and steamed eggs are 100%, fried eggs are 98%, scrambled eggs are 97%, poached eggs are 92.5%, fried eggs are 81.1%, and raw eggs are 30%~50%

.

From this point of view, boiled or steamed eggs should be the best way to eat them.

For children, steamed egg custard and egg drop soup are the most suitable, because these two methods can loosen protein and be easily digested and absorbed by children.

Reference: Baidu Encyclopedia-Eggs