Preserved eggs are made of duck eggs. Secondly, duck eggs are big and yellow. Duck eggs contain more minerals, which can promote digestive organs and appetite. Compared with eggs, pickled preserved eggs with duck eggs have lower cost and higher profit. Preserved egg is a traditional Chinese flavor egg product, which is developed from plant ash, alkali and other raw materials. There are pine needle crystals or patterns in the protein.
Preserved egg, also known as Songhua egg and changed egg, is an egg processing food invented by Chinese Han people. It is a unique food in China. It has a special flavor and can promote appetite. It is not only a delicacy, but also has certain medicinal value.
The main chemical component of preserved eggs is another protein, which contains sulfur. Over time, the egg yolk will also decompose into amino acids and release the gas hydrogen sulfide we usually call rotten egg smell.
Egg yolk itself contains many minerals, such as iron, copper, zinc and manganese. Hydrogen sulfide can react with these minerals to form sulfide. So these sulfides are produced when the egg yolk is blue and black. Most of these sulfides are extremely insoluble in water, so they are not absorbed by the human body. Although Songhua egg is nutritious and delicious, it is too alkaline to eat more.