What does it mean to remove sour meat

When buying meat, people may find that there are many different types of meat, such as fresh meat, frozen meat or acid-cured meat. Fresh meat and frozen meat should not be difficult for people to understand, but people have not known about acid-cured meat before and may find it a little strange. What is acid-cured meat? What are the benefits of eating this kind of meat? Now let me give you a detailed introduction to what it means to remove acid-producing meat.

Acid-depleted meat is made by slaughtering live livestock and naturally cooling them to room temperature. The carcasses are then sent to a cooling room where the lactic acid components in the meat are decomposed into carbon dioxide, water and alcohol under a certain temperature, humidity and wind speed, and then evaporated. At the same time, the macromolecular adenosine triphosphate in the cells is decomposed into the umami substance glycoside IMP (the main component of MSG) under the action of enzymes. The taste of the meat after acid depletion is greatly improved, and it tastes tender and fresh. The acidity and alkalinity of the meat are changed, and the metabolic products are decomposed and discharged to the greatest extent, thereby rendering them harmless. At the same time, the molecular structure of the meat is changed, which is beneficial to the human body's absorption and digestion.

Chilled meat, also known as fresh meat or cooled chilled meat, is a meat post-ripening process advocated by modern meat hygiene and nutrition.

Acid-depleted meat is made by slaughtering live livestock and naturally cooling them to room temperature. The carcasses are then sent to a cooling room where the lactic acid components in the meat are decomposed into carbon dioxide, water and alcohol under a certain temperature, humidity and wind speed, and then evaporated. At the same time, the macromolecular adenosine triphosphate in the cells is decomposed into the umami substance glycoside IMP (the main component of MSG) under the action of enzymes. The taste of the meat after acid depletion is greatly improved, and it tastes tender and fresh. The acidity and alkalinity of the meat are changed, and the metabolic products are decomposed and discharged to the greatest extent, thereby rendering them harmless. At the same time, the molecular structure of the meat is changed, which is beneficial to the human body's absorption and digestion.

There are three main types of fresh meat sold on the market: hot fresh meat, frozen meat and acid-exhausted meat (also known as cold fresh meat).

Hot fresh meat is fresh meat that is slaughtered and sold immediately without any cooling treatment. It occupies a large proportion in the market. The disadvantage of this kind of meat is that the meat temperature is high after the animal is slaughtered, and it is impossible to package. The naked meat is sold and becomes a breeding ground for bacteria, contaminating the meat source. The quality of the meat is also reduced. The hardness of the meat increases by 10 to 40 times, and it becomes dry, lacks elasticity, and has a lower tenderness and flavor. Frozen meat is usually frozen at below -18℃ and then thawed when eaten. This process will cause the cells in the meat to rupture and water to be lost, affecting the taste of the meat. Chilled meat, also known as fresh meat, refers to meat that has been strictly quarantined and rapidly cooled after slaughter, so that the carcass temperature (with the center of the hind leg meat as the measurement point) drops to 0-4°C within 24 hours, and is always kept fresh at 0-4°C during subsequent processing, circulation and sales.

Fresh meat is safe, hygienic, delicious, tender and has high nutritional value. This is because fresh meat has its own unique maturation rules, that is, a series of physical and chemical changes will occur inside the meat of livestock and poultry carcasses after slaughter, and rigor mortis, thawing and softening processes will occur successively, resulting in the meat being soft and juicy, and producing a unique taste and smell. We call this series of processes that make the meat soft and juicy and improve the flavor meat maturation, and in industry it is called meat acid discharge. This process is usually carried out under low temperature conditions, also called cooling and acid discharge. The time experienced in this process varies depending on the type of livestock and poultry and the temperature. Under normal circumstances, it takes 3 to 5 hours for pork, 5 to 7 hours for mutton, and 10 to 14 hours for beef from slaughter to maturity. [1]

After the animals are slaughtered, their mental stress causes their body temperature to rise by an average of 1°C. 30°C is suitable for bacterial growth and reproduction. In order to avoid bacterial growth, it is necessary to use rapid cooling.

The transformation of muscle tissue into edible meat undergoes certain changes, including rigor mortis, thawing and maturation of the meat. For example: after an animal dies, lactic acid is produced in the body due to biochemical reactions. If it is not cooled sufficiently in time, the lactic acid accumulated in the tissues will damage the quality of the meat. Compared with the hot fresh meat that is slaughtered in the early morning and sold in the early morning, the acid-removed meat is placed at a cooling temperature (0℃-4℃) for 12-24 hours.

The growth and reproduction of most microorganisms are inhibited, and Clostridium botulinum and Staphylococcus aureus no longer secrete toxins. The enzymes in the meat take effect, breaking down some proteins into amino acids, while emptying the blood and body fluids that account for 18%-20% of body weight, thereby reducing the content of harmful substances and ensuring the safety and hygiene of the meat. Compared with frozen meat, acid-depleted meat is soft and elastic, easy to cook and rot, has a delicate taste, is delicious, and has a high nutritional value because it has undergone a more complete thawing process. [2]

Food Features

The acid removal process makes the acid-removed meat have the following characteristics:

1. Long-term cooling at 0~4℃ will inhibit the activity of enzymes and the growth and reproduction of most microorganisms. At 3.3℃, ​​pathogens (Staphylococcus, Salmonella) stop multiplying, and botulinum acid bacteria no longer secrete toxins, thus avoiding meat corruption and ensuring the safety and hygiene of meat.

2. A layer of dry oil film is formed on the surface of chilled meat in a cooling environment, which can reduce water evaporation and prevent microorganisms from invading and multiplying on the surface of the meat.

3. Delayed maturity

It changes the fiber structure of muscle tissue, making it easier to chew and digest, and also has a higher absorption rate.

4. More nutritious and tastes better. During the acid excretion process, the nucleoprotein adenosine triphosphate decomposes and eventually produces phosphate and hypoxanthine, which increases the aroma of the meat. The myosin in the protein produces glutamate under the influence of enzymes, which increases the flavor and nutrition of the meat. Therefore, fresh meat is more nutritious, the meat is soft and elastic, easy to cook and rot, has a delicate taste, and is juicy and delicious.

5. Easier to cut, and the cut surface has a special aromatic smell. [1]

Method

From live animals to the dining table, fresh meat generally goes through the following process: pigs that have passed the origin inspection are slaughtered in a slaughterhouse, and after passing the quarantine and quality inspection, they are cooled at 0~4℃ to drain the acid for 24~48 hours. The products are cut and packaged in a cooling room at 0~4℃, then transported to wholesale and retail outlets by refrigerated transport vehicles at 0~4℃, and displayed and sold in refrigerated display cabinets at 0~4℃. Finally, consumers should store it at 0~4℃ after purchase. The entire production process of fresh meat is always kept at 0~4℃, forming a cold chain system unique to fresh meat, with each chain closely connected and uninterrupted.

Take the production process of acid-drained pork of a certain enterprise as an example. The process is to bathe the pigs in warm water before slaughter.

High voltage electricity is used to stun pigs to the sound of music, and the pigs are slaughtered in a stunned state, which ensures the quality of the product. The entire production line is made of stainless steel to ensure the safety and hygiene requirements of the production equipment. [1]