Salted duck eggs will "ooze oil", where does this oil come from?

Salted duck eggs, as the name suggests, are a kind of food made from pickled duck eggs. They have a long history in my country and are very popular among the people. Medically speaking, salted duck eggs are sweet and cool in nature, and have the effects of nourishing yin, clearing the lungs, strengthening muscles, moisturizing the skin, and removing heat.

Salted duck eggs can be eaten all year round. They have high nutritional value. They contain protein, phospholipids, vitamin A, vitamin B2, vitamin B1, vitamin D, calcium, iron, potassium, phosphorus and other nutrients. They can supplement minerals such as iron and calcium for the human body, help bones develop better and prevent anemia.

Whether the salted duck eggs are oily has become a hard-core indicator for distinguishing the quality when purchasing.
Do you know why it oozes oil? In normal circumstances, the protein and fat in fresh eggs are evenly distributed in an emulsion. When fresh eggs are cooked directly, the emulsion solidifies and becomes a clot. The oil does not have time to precipitate and is still dispersed in the protein clot, so no oil is seen.

The reason why salted duck eggs are "oily" is inseparable from their composition: duck eggs are rich in protein and fat, and most of the fat in the whole duck egg is in the yolk, except for a small amount in the egg white. There is also some oil in the yolk, so the fat content in the yolk is very high. During the salting process of fresh eggs, salt invades the eggs. Salt can reduce the solubility of protein in water and cause the protein to precipitate. This process is called "salting out."

After being "salted out", the protein that acts as an emulsifier will slowly denature and solidify, causing the oil droplets that were originally dispersed into tiny drops to gather together and become large oil droplets, which become egg yolk oil.

Therefore, after the salted duck eggs are cooked, the entire egg yolk becomes oily, and because the egg yolk contains red and yellow yolk and carotene, the egg yolk oil appears red and yellow.

Salted duck eggs are produced in many places across the country, but only Gaoyou, Jiangsu is the most famous. In fact, in addition to Gaoyou, Jiangsu, there is another place where salted duck eggs are also very famous, that is, the roasted sea duck eggs in Beihai Mangrove, Guangxi. Beihai Mangrove, Guangxi has a superior geographical location and climatic conditions, which has created a unique growth environment for ducks raised on the seaside. If the ducks are well raised, the duck eggs will be good!

Ducks raised in mangroves often feed on small fish, shrimps, crabs, snails and other marine life in the water. This makes sea ducks fat and lay many eggs, and the yolks are crystal red, delicious and fragrant. Sea duck eggs are also relatively large, and common duck eggs are generally only between 52g and 70g. Eggs are rich in calcium, zinc, potassium, iron, etc., a variety of trace elements beneficial to the human body and more than 10 kinds of vitamins. The calcium content of 100g of sea duck eggs is equivalent to 3 times that of 100g of ordinary beef, and the protein content is equivalent to 5 times that of 100g of ordinary milk. It can be said that the nutritional value is very high. However, although salted duck eggs are delicious and tempting, the salt content is relatively high, so it is okay to eat them occasionally to satisfy your cravings, but you must not be greedy.