Why can pigs be eaten in rural areas, and pork in supermarkets should be acidic?

What effect does acid discharge have on meat?

This is a mature technology in modern nutrition and meat science. The freshly slaughtered meat is cooled, so that the temperature of the meat drops to about 0 degrees within 1 day, and the humidity is kept at 90% for about 8-20 hours. In this process, enzymes in meat will decompose part of protein into amino acids, at the same time, it will empty blood and part of body fluids, inhibit the growth of most bacteria, thus changing the fiber structure of meat, greatly reducing the content of harmful substances and making it more edible. How to distinguish sour meat?

Acid-free meat is blood red in color, with poor surface gloss and the smell of meat and oxalic acid.

The color of acid-discharged meat is bright red and slightly dark, and it doesn't smell like meat or oxalic acid.

Sour meat increases flavor and nutrition, and it is easier to cook thoroughly and tastes more delicate.