1. Preserved eggs become preserved eggs. They are made by hand. Preserved eggs are the traditional food of our people. Because of its unique flavor, excellent taste, long shelf life and convenient carrying, it is favored by people. The process of processing fresh eggs into preserved eggs is essentially a complex chemical reaction process. Although there are many formulas and techniques for processing preserved eggs, the main raw materials generally include: calcium oxide (CaO), soda ash (Na2CO3), plant ash (mainly K2CO3), salt, tea and so on. Based on the actual situation of students, this paper takes two preserved eggs as examples to explain how to process preserved eggs in the laboratory and the chemical principle: L. The preserved eggs on the table with gray formula are very delicious to eat, but they are covered with an ugly "coat". Don't underestimate it, it is the key to making preserved eggs, and this is the gray material. The formula of the ash material is: 50g of quicklime, 3g of soda ash, 2g of plant ash 1 g, 2g of salt, 20g of water and trace of tea. 2. Ash preparation According to the requirements of the ash formula, put the required ash into a container (just a big beaker) and prepare it with water. Quicklime first reacts with water to produce hydrated lime, which then reacts with potassium carbonate, the main component of soda ash and peat, to produce sodium hydroxide and potassium hydroxide respectively. The chemical equation of the reaction is as follows: Cao+H2O = Ca (OH) 2 Ca (OH) 2+Na2CO3 = CaCO3 ↓+2 NaOH Ca (OH) 2+K2CO3 = CaCO3 ↓+2kOH. In order to make the substances in the hair fully react, it can only be used after 24 hours. 3. preserved egg processing: roll fresh eggs in the prepared ash several times to evenly coat the surface of the eggshell with a layer of ash powder, take them out, and then roll them in rice bran or sawdust several times to stick a layer of rice bran or sawdust on the ash. Squeeze it gently by hand to make it tight, and put it into a container prepared in advance. The second fresh egg is also treated in this way. The container is sealed and placed at ambient temperature 18 ~ 24℃. /kloc-you can eat it in 0/0 days. On the day of 10, the inside of the egg is not as calm as a deep pool. The strong alkali (NaOH, KOH) in the ash penetrates into the egg white and egg yolk through the eggshell, and reacts with protein in the egg white and egg yolk, so that protein decomposes and solidifies, and a small amount of hydrogen sulfide (H2S) gas is released. At the same time, the infiltrated alkali will further neutralize the amino acids decomposed by protein, and the crystals of the generated salt will precipitate in the preserved egg protein of the gel peptide, resulting in a white "pine flower" (which is also the reason for the name of preserved egg). However, hydrogen sulfide gas reacts with minerals in egg white and egg yolk to generate various sulfides, so the colors of egg white and egg yolk have changed, with egg white showing a special dark brown color and egg yolk showing a dark green color. Salt can make preserved eggs shrink out of the shell and add flavor. Tannin and aromatic oil in tea can color the solidified protein and increase the flavor of preserved eggs. And why don't preserved eggs go bad for half a month or even months? First, because there is salt in it, salt has antiseptic effect; First, alkaline substances kill bacteria in fresh eggs that may lead to protein's spoilage. 10 days later. When you sit at the table and taste this delicious preserved egg, your heart will be filled with joy, and you will think about when to cook more. But next time you are ready for mass production, don't forget to change the formula of ash in proportion.