When an animal dies suddenly, an acid substance is produced in the body. Acid excretion is eliminated by rapid freezing or other methods. Eating meat without acid excretion will have a bad influence on the human body. To be precise, acid-discharged meat should be called "cooling acid-discharged meat". It is the post-ripening process of meat advocated by modern meat hygiene and nutrition. As early as the 1960s, developed countries began to study and promote acid-discharged meat. Nowadays, the market share of acid-discharged meat in developed countries has almost reached 1 0,000%. After animals are slaughtered, certain changes will occur when muscle tissue is transformed into edible meat, including the hardness, thawing and maturity of meat. For example, lactic acid is produced by biochemical action after animal death. Lactic acid accumulated in muscle tissue will damage meat quality if it is not cooled in time. Compared with the hot fresh meat slaughtered in the early morning and put on the market in the early morning, the acid-discharged meat kept 12-24 hours at the cooling temperature (0-4), which inhibited the growth and reproduction of most microorganisms, Clostridium botulinum and Staphylococcus aureus no longer secreted toxins, and the enzyme action in the meat decomposed part of protein into amino acids, and at the same time, blood and body fluids accounting for 18-20% of the body weight were evacuated. After people eat pork, the protein in the meat will be converted into amino acids by enzymes in the human stomach, which is convenient for the human body to absorb. After artificial processing, part of protein in pork is converted into amino acids before people eat it, but only part of the conversion is completed ahead of schedule. Compared with ordinary pork, the nutritional composition of pork with acid discharge has not changed, which means that the nutritional composition of pork with acid discharge is basically the same as that of ordinary pork. Sour pork is easier to cook, rot and taste better because it does exclude some things from pork. Foods like this, which convert protein into amino acids before eating, are especially beneficial to patients after surgery. So, what exactly is cold meat? Conceptual analysis: deacidification of meat is a post-ripening process advocated by modern nutrition. The cooling and acid discharge of pork specifically refers to that pigs are strictly quarantined by animal inspectors and proved to be hygienic, and immediately enter a cold storage environment after being slaughtered in a designated slaughterhouse, and the meat is cooled with relevant equipment, and then cut, boned, packaged, processed, stored, distributed and sold in a low-temperature environment until they enter the refrigerator or kitchen of consumers, and the meat temperature is always kept between -2℃ and 4℃. In this way, after cooling at low temperature for 24-48 hours, the meat has completed the "ripening process" (also known as the acid discharge process). Amylase in meat converts animal starch and glucose into lactic acid, which can make the connective tissue of meat tender. This kind of meat that has completed the ripening process is called "cooled and acid-discharged meat". Nutritional components: Compared with ordinary meat, the manufacturing process of acid-discharged meat can not only avoid harmful substances remaining in the meat, but also avoid bacterial reproduction by immediate freezing. Moreover, the delay of time changes the fiber structure of muscle tissue, making it easy to chew and digest, with high absorption and utilization rate and better taste. In the process of acid discharge, it also increases the flavor and nutrition of meat. In addition, "cooling and acid-discharging meat" also uses a variety of processing methods to facilitate people's cooking, such as shredded pork, sliced meat, diced meat, minced meat and so on. So that consumers do not need to wash and cut in the kitchen after eating, thus reducing pollution in the production process. How to distinguish acid-discharged meat: color, non-acid-discharged meat is blood red, and the surface lacks luster; The meat quality of acid-discharged meat is slightly black and bright red; Taste: non-acid-discharged meat has fishy smell and grassy sour taste, while acid-discharged meat has no fishy smell and grassy sour taste; The meat quality of non-acid-discharged meat is firewood, which is not perishable, and the meat quality of acid-discharged meat is smooth, tender and delicious. The sour meat is naturally cooled to normal temperature after the beef is slaughtered, and then the two parts of the carcass are sent to the cooling room. Under certain temperature, humidity and wind speed, lactic acid in beef is decomposed into carbon dioxide, water and alcohol, and then volatilized. At the same time, adenosine triphosphate in the cell is decomposed into umami glycoside IMP (the main component of monosodium glutamate) under the action of enzyme. After acid removal, the taste of beef is greatly improved, fresh and tender, and the pH value of meat is changed. At present, the sour beef sold in the market mainly includes beef bone (steak), beef tenderloin (loin), sirloin (waist plate), T-bone and fat beef series. These products are mainly used for roasting, roasting, frying and fat beef hotpot series. Why is sour beef popular? First of all, the cattle slaughtered by sour beef are extremely fat and high-quality beef cattle. Shaanxi Qinchuan cattle, Shandong Luxi cattle, etc. Meat is rich in marbles, and its nutritional value is higher than that of ordinary beef. It is soft and juicy, delicious, soft in color, fat but not greasy, thin but not firewood, easy to chew and digest, and its nutrition is highly absorbed and utilized by the human body even if it is eaten raw. Secondly, beef processing needs strong technical force, first-class equipment, acid discharge warehouse with computer automatic control of temperature, humidity and wind speed, strict technological process, advanced processing technology and excellent management. The meat quality of pickled meat is soft and elastic, and the meat quality is delicate, and there is no obvious difference between hot fresh meat and frozen meat in color and meat quality. The deacidification process of deacidified meat can reduce the content of harmful substances in meat; The low-temperature production technology of acid-discharged meat can avoid microbial pollution to meat quality. The real meaning of sour meat must be the meat after slaughter. Then, the acid is cooled and discharged for 4 hours in the cooling and acid discharge bin, and then the sub-packaging is completed at 0 ~ 4℃ in the workshop. At the same time, packaging, storage, transportation and sales are also carried out under low temperature control. Some people mistakenly think that "as long as it is frozen below 4℃ for 7 hours, it is sour meat", but they ignore all the details before and after. Even we can see the sour pork distributed on the spot in the supermarket. However, it is very likely that the meat we bought only completed one or several steps, not the real meat. The real sour meat is sold in frozen vacuum packaging! Mostly beef and smoked salmon (not frozen).