The strong alkali in plant ash penetrates into egg yolk and egg white through the eggshell, and a chemical reaction occurs. Neutralizing with protein and amino acids in duck eggs and solidifying to produce preserved eggs. Duck eggs are generally used as preserved eggs, because the smell of duck eggs is heavy, and ordinary eating methods can't hide the taste, so people generally eat duck eggs as preserved eggs.

The color of preserved eggs will be reddish-brown or dark brown in protein and dark green or orange-red in yolk due to protein under the action of strong alkali. Sometimes the yolk is yellow, indicating that this preserved egg may not be fresh, and it is best not to eat it.

Pay attention to eating preserved eggs

Cholesterol in any egg yolk is high, and middle-aged and elderly people and people with hyperlipidemia should eat it in moderation. People with gastric ulcer and hyperacidity should not be jealous. Ginger is a warm food, and people who get angry should not eat more. Eating preserved eggs must be a taboo for patients with cardiovascular and cerebrovascular diseases. You must eat less and pay attention to moderate consumption.

Children can't eat preserved eggs: the growth and development of children's internal organs are not very sound, and many functions are incomplete. Preserved eggs are preserved foods, which contain many harmful ingredients, such as lead with excessive heavy metals and organic chemical alkali, which makes children very sensitive to lead. This substance is very harmful to children, and it is very prone to calcium loss and hypoplasia of bones and teeth.

For the above contents, please refer to Baidu Encyclopedia-Preserved Eggs, People.com-What if you eat preserved eggs every day? Who can't eat preserved eggs?