Changes in meat after slaughter of pigs and during storage

After the slaughter of an animal, complex enzymatic, biochemical and physicochemical processes take place in the meat, which largely determine its quality and technological properties. In the first 2-3 hours after slaughter, the meat has a tender texture, high water-holding capacity and swelling. Then these indicators worsen. However, with further aging under certain conditions for several days, the meat becomes tender and fragrant, acquires good taste, meat juice is released from it, i.e., meat ripens.

The process of maturation of meat is conventionally divided into rigor mortis and softening (actual maturation). Characteristic signs of ripe meat: the appearance of a “dry crust” on the surface of the carcass, a specific slightly sour smell, an elastic texture and an acidic environment inside the muscles. To determine the degree of maturation of meat, histological and physico-chemical indicators can be used. In the meat of sick and lean animals there is little glycogen, lactic acid, all maturation processes proceed superficially. Such meat has low taste and culinary qualities, is worse absorbed by the body, and is poorly stored.

During long-term storage of ripe meat in an unfrozen state, deep autolytic processes occur in it, under the influence of which proteins and fats break down into simpler substances, as a result of which the texture, taste, smell and color of meat change. With deep autolysis, the color of the meat becomes brown, the texture becomes flabby, a musty smell appears, and watery meat juice is released from it. The surface of the meat becomes wet, it accumulates a lot of protein breakdown products. As a result of the development of putrefactive microflora, meat quickly deteriorates.

Changes in meat during storage occur due to the vital activity of microorganisms that have penetrated into it. Its contamination can occur in vivo in case of slaughter of sick animals, violation of the conditions of pre-slaughter exposure, as well as in the process of cutting, storing and transporting carcasses. Of the defects of meat, mucus, mold, souring, sunburn, and rotting should be noted.

Sliming meat

Occurs when storage conditions are violated, sharp fluctuations in temperature and humidity, insufficient cooling of carcasses. This defect is caused by mucus-forming microorganisms resistant to low temperatures (micrococci, lactic acid bacteria, yeast, etc.), which develop well even at a temperature of 0 °C. They are not dangerous to humans. The surface of the meat becomes sticky, gray-white in color, sometimes with an unpleasant sour musty smell.

Meat with such a defect cannot be stored, it is washed with water or a 15-20% salt solution, dried and ventilated, and used as quickly as possible.

Mold of meat

Occurs when mold fungi appear on the surface, which is facilitated by high humidity of meat, poor air ventilation in the storage. On the surface, colonies of various shapes and colors are formed (white, gray or dark green, black, etc.). Mold creates conditions for the development of putrefactive microflora. If the meat is superficially affected by mold, it is washed with a 20-25% solution of table salt or 3-5% acetic acid, ventilated and dried.

Heavily affected meat in the presence of a musty smell that does not disappear when aired is not allowed to be eaten.

Soured meat

They cause acid-forming bacteria if the meat is poorly bled, damp, or stored at high temperatures. It softens, acquires a gray color with an unpleasant sour smell. On such meat, mold and mucus-forming bacteria intensively develop. Correction of this defect is achieved by washing with water.

Tan meat

It occurs in the first hours after slaughter when meat is stored in a stuffy room with a temperature above 18-20 ° C, when cooling or freezing conditions are violated, as well as when fresh meat is stored in a dense airtight container. At the same time, it becomes brown-red or grayish with a greenish tint, a strong sour smell appears. To eliminate this defect, the meat is cut into small pieces and well ventilated in the air.

rotting meat

The process of protein breakdown due to the vital activity of putrefactive microorganisms in conditions of high temperature, humidity and oxygen access.

In the initial stage of spoilage, meat is more dangerous than in the later one, since the accumulated putrefactive substances, amines and bacterial toxins, turn into less poisonous as the process of decay deepens. Rotting proceeds in steps, accompanied by a change in the structure of tissues and physico-chemical parameters.

Anna Evans

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