Cook the meat with cold water is because the meat contains blood. Boiling with boiling water will make the blood in the capillaries on the surface of the meat suddenly coagulate, instead of gradually forcing the blood out, thus affecting the taste and color of the meat. If this step is used for meat, it is usually the step before stewing, which can make the protein on the surface of the meat shrink. When stewing again, the nutrients in the meat can remain in it and will not be completely integrated into the water.

In the process of ironing ribs, a layer of yellow and white foam will float on the water. This kind of floating dog is not the same as the foam that disappears when boiling water. It can carry some substances that look dirty, and with the bubbling of boiling water, it will be more and more, and it won't take long to occupy the whole pot surface. Change this pot of water before cooking soup, and the noodle soup will be much clearer.

Some people say that this kind of floating foam is full of dirty things on meat and some toxic and harmful substances. Eating in the body will make people uncomfortable and even sick.

Seeing this statement, I really want to apologize for these ingredients. How did a clean and well-cared-for pig turn into a pile of harmful things when it was cooked? You can eat it all, please don't hurt it ~

In fact, these floating foams are mainly composed of fat in meat and protein in blood. The water temperature of 100℃ destroyed the spatial structure of hemoglobin in pig blood, resulting in the exposure of polypeptide chains in protein. When these polypeptide chains combine with bubbles in boiling water, they become the dirty floating bubbles we see.

Then, since the fat and protein in these floating foams are harmless ingredients, why should we fish them out when we are in cook the meat? Is this obsessive-compulsive disorder's rude ignorance of noodle soup?

Of course not. The odor substances in pork-the source that makes you feel fishy-are rich in blood and body fluids of pigs. These substances include aliphatic amines, aldehydes and ketones, heterocyclic compounds and so on. It is more soluble in fat than in water. For a pot of soup, part of it will be dissolved in the upper grease and floating foam containing a lot of fat. If you don't get rid of these floating foam, it is equivalent to conniving at the fishy smell floating in the soup pot. There is nothing wrong with the food, just the taste, but the difference is not a little.