Preserved eggs, also known as preserved eggs, preserved eggs, eggs wrapped in gray, etc., are a kind of flavor egg products, and their smooth and fragrant, fresh and smooth taste and unique color and fragrance have attracted many diners.
The process of making preserved eggs is not complicated. The main raw materials are fresh eggs, quicklime, soda ash, salt, water and plant ash. The specific production method is: put soda ash and salt into a jar, pour boiling water, and after the two are fully dissolved, add plant ash and quicklime in batches, and after the quicklime and other components are melted, the ash is finished. Then spread the ash evenly on the fresh eggs and seal them in a jar. After about two months of curing, the protein in the eggs solidified and preserved eggs were produced.
Quicklime and soda ash are the keys for fresh eggs to become elastic solids, which utilize the principle that when eggs are in alkaline solution, protein will show gel properties. Therefore, the raw material ratio of preserved eggs must be accurate. Once the dosage control of the formula is wrong, protein will be hydrolyzed in alkaline solution, and the preserved eggs denatured in protein will be inedible.
There are still a series of complex chemical reactions in the production of preserved eggs. First of all, the main component of quicklime used in raw materials is calcium oxide, which reacts with water to form hydrated lime? Calcium hydroxide; The raw material also contains soda ash, and calcium hydroxide reacts with soda ash in the solution; At the same time, plant ash contains soluble component potassium carbonate, which also reacts with calcium hydroxide.
Sodium hydroxide, potassium hydroxide and calcium carbonate produced in this chemical reaction ionize hydroxide ions, potassium ions, sodium ions and calcium ions. When the egg is immersed in the feed liquid, these ions penetrate into the eggshell and react on the protein through chemical reaction, and geometric crystals form beautiful ones. Songhua? .
Why are the yolks of preserved eggs mostly bluish-black? This is also caused by chemical reactions. Protein in egg yolk contains high sulfur. In the production of preserved eggs, egg yolk will also decompose amino acids and release a very smelly gas? Hydrogen sulfide, that's why preserved eggs smell strange and smelly. Egg yolk itself contains many minerals, such as iron, copper, zinc, manganese, etc. Hydrogen sulfide can form sulfide with these minerals. Sulfide combines with pigment in egg yolk and various metal ions in egg, which makes egg yolk produce various colors. Egg yolk turns blue-black, which is due to the action of sulfide.
In many people's minds, eating too many preserved eggs may lead to lead poisoning. In fact, the main source of lead in preserved eggs is a substance called plumbum. And people's impression that preserved eggs preserved by quicklime, lead and other substances have actually been basically preserved? Lead-free preserved eggs Instead of technology. With the maturity of lead-free technology, the lead content in preserved eggs gradually decreased. At present, the lead content of preserved eggs produced on a large scale by regular enterprises can basically be controlled at about 0. 1-0.2 mg. However, if it is preserved eggs produced by small workshops and factories, the lead content is relatively high. Therefore, preserved eggs are delicious, but you should choose a regular manufacturer when eating.