Is the green yolk poisonous? Avoid these 3 common mistakes when eating eggs

Many people eat boiled eggs every morning, and the first dish many people learn to cook is scrambled eggs with tomatoes.

From this perspective, it is really very common, but its nutrition is extraordinary. It is a good source of high-quality protein, and the quality of this protein is not just good, it is super good. It is used as a reference to judge the quality of protein in other ingredients.

Even though this is such a common but super nutritious food, people have many misunderstandings when eating it. These misunderstandings make eggs not nutritious enough or safe enough. Here are the 3 most common misunderstandings about eating eggs.

1. Is egg yolk less nutritious than egg white?

Some people think that egg yolks have little nutritional value and are full of fat, so they are not as good as egg whites.

In fact, egg yolk is more nutritious than egg white. Where is the nutrition?

First, the protein content of egg yolk is higher than that of egg white. Egg white contains about 11.6% protein, while egg yolk contains 15.2%. [1]

Second: In addition to protein, almost all minerals and vitamins are found in egg yolks. Nutrients such as lutein and zeaxanthin, which are beneficial to vision development, are also found in egg yolks.

Some people don't eat egg yolks because they are high in energy. Compared with egg white, egg yolks do have high energy, and the energy of egg yolks is 5.5 times that of egg whites. However, according to the recommendations of the Chinese Dietary Guidelines, if you eat one 50g egg a day, your calorie intake is only about 70kcal.

Some people are also worried that egg yolks will increase blood cholesterol. This is not a big concern, as studies have shown that consuming 3 to 4 egg yolks per week has little effect on serum cholesterol levels. [2] If you are worried about the impact on blood cholesterol, you can limit your intake to 4 egg yolks per week. Ordinary people can follow the Chinese Dietary Guidelines to eat 50 grams per day, or about 1 egg yolk.

2. Is boiling eggs in water more nutritious?

If you search online, you will find many folk remedies about curing diseases by mixing eggs with boiling water. Some people also firmly believe that mixing eggs with boiling water is more nutritious, so many people eat it this way.

A 2003 survey on egg hygiene conducted by the Jining Municipal Health and Epidemic Prevention Station showed that 21% of the more than 300 consumers surveyed had the habit of mixing eggs with boiling water. [3]

However, eggs are easily contaminated with Salmonella, which can only be killed when heated to 80°C for more than 12 minutes. [4]

However, even if the eggs are taken out of the refrigerator and boiled with water, the temperature may not reach 80 degrees Celsius. If the water used is not freshly boiled, the temperature may be even lower. In addition, most people just stir the water and drink it, so the time is less than 12 minutes. This cannot guarantee that all Salmonella will be killed, which will increase the risk of food poisoning.

Therefore, it is not recommended to boil eggs in boiling water, especially for people whose immunity may be weaker, such as the elderly, pregnant women, and children; if you like the taste of egg drops, you can make egg drop soup.

In addition, it is not recommended to eat soft-boiled eggs because the yolk will not solidify and there is no guarantee that all Salmonella will be killed.

3. If the egg yolk turns green, it is poisonous and cannot be eaten?

Normally we will find that the yolks of boiled eggs will turn green, especially the tea eggs sold in breakfast shops, where the yolks will turn green particularly seriously.

Some health programs also mentioned that if you boil eggs for more than 10 minutes, the yolk will turn blue, which will affect iron absorption.

In fact, it is normal for the surface of the yolk to turn dark green after boiling eggs for a long time.

This is because eggs contain cysteine ​​and iron. If heated for a long time, cysteine ​​will decompose into hydrogen sulfide. Hydrogen sulfide reacts with the iron in the egg yolk to produce dark green iron sulfide, so the surface of the egg yolk turns dark green.

As for the impact on iron absorption, there is no need to worry. The iron content in eggs is only 2 mg/100 g, which is about half of the iron content in pork. In addition, the iron in eggs is also affected by phosvitin in the yolk, and the absorption rate is only about 3%. [5]

Therefore, if you want to supplement iron, you can't rely on eggs. It is more reliable to eat red meat, animal liver, animal blood and shellfish.

Eggs are a good ingredient. They are not only nutritious but also easy to cook. Stay away from these 3 misunderstandings about eggs and eat eggs safely and nutritiously.