Because boiled eggs completely retain the nutritional value of eggs, the protein structure in fried eggs is destroyed by high temperature and frying, which leads to the decrease of nutritional value.
Boiled eggs directly retain the nutritional value of eggs because they do not add a drop of oil during cooking and the cooking temperature is not high. Because of high temperature and frying, the high molecular weight protein contained in egg white will become low molecular weight amino acids, which reduces the nutritional value.
Although fried eggs are delicious, we have to admit that boiled eggs are actually more nutritious. In the process of cooking, you only need to boil eggs in hot water without adding any seasoning, so the nutrients are not destroyed and it is more nutritious to eat. Eating a boiled egg every morning can supplement the protein needed by the body.
Matters needing attention in boiling eggs
Eggshells often break when they are boiled. The basic method to avoid breaking the shell is "boiling water to cool the egg". The reason of eggshell rupture is that the volume of egg white and yolk will expand when heated, and the expansion rate of liquid is greater than that of solid eggshell. When the volume of liquid is greater than the capacity of eggshell, eggshell will break.
Put the cold eggs in a small colander and boil them in boiling water for 8 minutes, so that the eggs are thoroughly cooked (if you want to eat half-cooked eggs, you can reduce the cooking time), so as to avoid burning hands and breaking shells, and the time is easy to control. As long as you keep the water boiling, a small fire will do.
The most wrong way is to put the egg in cold water and heat it slowly, so that the heat can be transferred to the inside of the egg for enough time. The inside and outside of the egg white and yolk are heated and expanded at the same time, which causes the eggshell to burst. At this time, often before the egg white reaches the solidification temperature, the egg white will flow out of the eggshell and solidify into a white floccule.
The above contents refer to Baidu Encyclopedia-Eggs.