How did the pattern in the preserved egg come from?
Chemical reaction. The loose pattern in preserved eggs is hydrated crystals of magnesium hydroxide. During the curing process of duck eggs, alkaline components infiltrated into the eggs through the pores of the eggshell, which led to the gradual alkali solidification of egg white protein and the formation of hydrated crystals of magnesium hydroxide in the process.
Preserved eggs, also known as preserved eggs and preserved eggs, are egg processed foods invented by the Han people in China. They are unique foods in China, which have a special taste and can stimulate appetite.
Preserved eggs are not only delicious food, but also have certain medicinal value. Wang Shixiong's "Resting Diet Spectrum" said: "Preserved eggs, pungent, astringent, sweet and salty, can purge heat, sober up, purge large intestine fire, treat diarrhea and disperse astringency." Traditional Chinese medicine believes that preserved eggs are cool and can cure eye pain, toothache, hypertension, tinnitus and dizziness. Everyone can eat it: fire is the most suitable; Children, people with spleen-yang deficiency, people with cold-dampness diarrhea, patients with cardiovascular diseases and patients with liver and kidney diseases should eat less.
Note: Preserved eggs should not be eaten with soft-shelled turtle, preserved plum and brown sugar. Usage and dosage: Jiang Mo and vinegar should be used to detoxify preserved eggs; Preserved eggs are best eaten after being cooked. Preserved eggs also contain lead, so children should eat less. It should not be stored in the refrigerator for a long time.
Why is the yolk of preserved eggs bluish black?
In fact, this is also caused by a chemical reaction: the main chemical component of preserved eggs is another kind of protein, which contains sulfur in protein. After a long time, the egg yolk will also be decomposed into amino acids, releasing what we usually call rotten egg-flavored gas-hydrogen sulfide. Egg yolk itself contains many minerals, such as iron, copper, zinc and manganese. Hydrogen sulfide can react with these minerals to form sulfide. Therefore, the blue-black yolk is the source of these sulfides. Most of these sulfides are extremely insoluble in water, so they are not absorbed by the human body. In addition, because a large amount of protein in preserved egg yolk is decomposed into amino acids, the yolk of preserved egg tastes much fresher than ordinary eggs. Preserved eggs are nutritious and delicious, but they are too alkaline to eat. Suggestion: Add some old vinegar when eating preserved eggs, which can sterilize, neutralize some alkalinity of preserved eggs and taste more delicious.
How to buy preserved eggs?
Finished preserved eggs, eggshells are easy to peel and do not adhere, the protein is translucent brown solidified body, the surface of the protein has pine-like patterns, the yolk is dark green solidified, and some have sugar hearts. The cut egg pieces are colorful. The food is cool and refreshing, fragrant but not greasy, and delicious. The quality inspection and grading of preserved eggs is the last important process for manufacturers and should be carried out in accordance with relevant state regulations. Consumers should also make choices when buying goods. Preserved egg quality
Common inspection methods are: once observation, twice weighing, three shaking and four photographing.
One view: look at whether the packaging material is moldy, whether the eggshell is complete, and whether the shell color is normal (the green cylinder color is better).
Second, put the egg in your hand, gently throw it up and throw it several times in a row. If you feel elastic and trembling, the heavier egg is a good egg, otherwise it is a poor egg.
Three shakes: hold both ends of the egg with your thumb and middle finger, shake it up and down in your ear, and hear the sound of water or impact. If you can't hear the sound, it's a good egg.
Photo 4: If most eggs are black or dark brown and a few are yellow or light red, they are high-quality eggs. If most of them are yellow-brown transparent body, they are immature preserved eggs.
Taboos for eating preserved eggs:
1, son: Some preserved eggs contain heavy metals such as zinc and mercury in addition to lead. After being absorbed by children, these heavy metals may remain in the body, leading to calcium loss in the body, affecting growth and development, easily causing children to have symptoms such as loss of appetite and even affecting intelligence. Therefore, children are not advised to eat preserved eggs.
2. Pregnant women: Pregnant women absorb more lead in preserved eggs than ordinary people, so the blood lead level in the body will increase after eating preserved eggs, which may affect the growth and development of the fetus. So pregnant women should be careful when eating preserved eggs.
3. Nephropathy patients: This kind of people should not eat preserved eggs, because the content of protein, salt and phosphorus in preserved eggs is high. If they eat too much, it may increase the burden on the kidneys, which is manifested by an increase in glomerular filtration rate.
4. Patients with liver disease: The liver is an important metabolic organ and detoxification organ in the body. Heavy metals such as lead need to be metabolized by the liver. Therefore, if patients with liver disease eat preserved eggs containing heavy metals, they will not be able to metabolize well and may even aggravate their condition.
5, other people: Chinese medicine believes that preserved eggs are cold, people with spleen and stomach deficiency should be careful to eat, so as not to aggravate diarrhea, abdominal pain and other physical discomfort symptoms.