Dark green boiled egg yolk, should you eat it?

According to the HuffingtonPost, boiled eggs are nutritious, quick to prepare, easy on the stomach, and help you feel full longer. The typical color of chicken and duck egg yolks is bright yellow or dark yellow if boiled soft-boiled. However, in many cases, you will see that the outer layer of the yolk is green, even very dark (if you cut a boiled egg in half, you will see a thin green rim surrounding the yolk).

Many people feel worried about this phenomenon, even wondering whether they should eat it or not, and whether eating it is harmful.

Actually, the reason is that the person who boiled the egg boiled it for too long, changing the ingredients in the egg. Under the influence of heat, when enough time has passed, the hydrogen sulfide (H2S) in the egg white will react with the iron in the egg yolk, forming blue-black iron sulfide FeS. That is why the blue color only appears on the outer edge, where it comes into contact with the egg white.

This green color is not harmful to the health of the eater, nor does it affect the taste, it only reduces aesthetics.

If you don't want a green ring on your hard-boiled egg yolk, just don't boil it too long. If you like the rich taste of hard-boiled eggs, stop at 11 minutes and turn off the heat.

If you want your eggs hard-boiled, boil them for only 9 minutes. For soft-boiled eggs, 3 minutes is a good amount of time. You can wait 5 minutes if you want the yolk to start to thicken, or 7 minutes if you want it to be hard-boiled but still pink in the middle.

How to prepare nutritious and safe eggs

Because there are so many ways to prepare eggs, many people wonder how to eat eggs to retain the most nutrients and safety. From an expert's perspective, you should prioritize the following two types of preparation:

Hard boiled eggs

Many people mistakenly believe that eating raw eggs is more nutritious, but based on the absorption and digestion after eating eggs, boiled eggs (with shell) retain up to 99% of their nutrients.

It should be noted that eggs need to be boiled at the right temperature, just cooked, eaten slowly, chewed thoroughly and swallowed slowly for better digestion. The best way to boil eggs is to put cold water in the pot, wash the eggs and boil over low heat until the water gradually heats up. After the water boils, continue to simmer for 2 minutes, turn off the heat and continue to soak the eggs in the pot for another 5 minutes.

Steamed eggs without shell

In addition to boiling, steaming eggs is also a way to cook eggs that ensures nutrition and safety. Science has proven that cooking at high temperatures, using a lot of oil or spices will change and reduce the protein, minerals, and nutrients in eggs.

Remember to remove the eggshell before steaming, steam instead of putting it in a rice cooker or steaming with other foods. Steam on low heat for about 7-10 minutes and then eat hot. Although some substances such as riboflavin, lutein and other water-soluble vitamins are slightly reduced, this cooking method still retains 97% of the nutrition of the egg.

Nguyen Mai (synthesis)

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