Blanching has many effects on meat processing.
First of all, remove blood stains and fishy mutton. This is an important step in most meats with strong flavor such as beef and sheep, and its effect is also obvious. Most chickens, ducks, geese and rabbits are also blanched, and some pork is also blanched.
There is a debate between boiling water in cold water and boiling water. I have tried both. The effect of boiling in cold water is better for removing blood stains, and both are good for removing fishy smell.
Secondly, blanch water can also remove greasiness. If you blanch water for a long time, a large layer of oil will float on the water surface, which shows its effect.
Thirdly, blanching can remove purine from meat, which many people may not know. Purines will dissolve in large amounts in boiling water (so gout patients are taught to drink less soup). When the meat is blanched, simmer it in the pot for a few more minutes, and most of the purines in the meat will dissolve.
Finally, the shape of the blanched ingredients is basically fixed, which facilitates subsequent processing and shaping, or has a good-looking appearance. For example, the beef in clear soup in restaurants is square in shape, as is the braised Dongpo pork.