After boiling for more than seven minutes, the yolk becomes hard and the edge is gray, and the longer it takes, the more obvious it is.

Generally speaking, the best state of boiled eggs is that the egg white has solidified, while the yolk has just solidified, and the texture is soft and tender, and the color is golden. Egg white and yolk solidified, indicating that the central temperature can reach about 70℃ at this time, salmonella has been killed and anti-nutritional substances can be removed; The egg yolk has just solidified slightly, which means that the cooking time will not be too long, and the oxidation degree of nutrients is relatively low at this time.

The following is a timetable for boiling eggs, for your reference:

1, boil for two minutes, at this time, the egg yolk is orange, and it is a little sticky at first, and it is not ripe.

2. Boil for four minutes. The yolk is bright yellow and soft. The center is still not semi-solid and just cooked.

3. After boiling for five minutes, the yolk is still not bright yellow, and the center is congealed and medium-cooked.

4. Boil for six minutes, the center of the yolk solidifies, and the periphery has begun to dry and fully cooked.

5. After boiling for more than seven minutes, the yolk becomes hard and the edge becomes gray, and the longer it takes, the more obvious it becomes.

Extended data:

It is not appropriate to boil eggs too long or too short;

1, eggs cooked for too long will destroy their nutrients. Boiling eggs for too long will not only lead to the destruction of nutrients such as B vitamins and vitamin E, but also lead to the oxidation of fatty acids and cholesterol.

Unsaturated fatty acids contained in eggs, such as linoleic acid, arachidonic acid and DHA, are easily oxidized. In the heating process, with the increase of temperature, the rate of oxidation reaction is accelerated, and the oxidized unsaturated fatty acids become "demons" like a "good citizen". When they enter the human body, they will increase the production of free radicals and even destroy DHA and cell structure.

2, the egg cooking time is too short and there are security risks. If heating is not enough, it can not only effectively kill harmful bacteria such as Salmonella, but also destroy anti-nutritional substances such as biotin-binding protein of eggs.

People's Daily Online-Cooking eggs pays attention to the fact that if eggs are cooked for too long, good fat will "go bad"