The effect of transportation and pre-slaughter detention on quality of pig meat

            This research aimed to determine the influence of stress of various etiologies in pigs caused by transportation and pre-slaughter conditions on meat quality. For this purpose, pigs were divided into 11 groups within two meat processing enterprises, depending on the duration of transportation (short, long without breaks and long with breaks) and the conditions of keeping animals before slaughter. Also, within the two groups were created two subgroups with pigs of different breeds. A total of 156 pigs were studied. Blood was collected from all pigs to determine cortisol and lactate levels, and a sample of meat from the longest back muscle. The pH of the meat was determined at different stages of its maturation, and the weight loss of the sample was determined. As a result of the research, it was found that the highest quality pork was obtained from pigs that experienced lower levels of stress before slaughter. Keeping pigs for 10 – 14 hours before slaughter without access to water and food resulted in higher stress levels, which were probably expressed in higher blood concentrations of cortisol and lactate. Pigs’ access to food and water during pre-slaughter retention allows for high-quality meat by reducing the influence of stress. Pigs’ access to water before pre-slaughter does not affect the stress level but positively affects the loss of meat weight during maturation. The higher the concentration of lactate in pigs’ blood, the faster the pH of the meat decreases after slaughter, which negatively affects its quality and moisture retention. If there is a long-term transport of pigs, there is no rest stop that can significantly reduce stress levels in pigs. Duration of transportation of pigs does not correlate with stress levels, as the conditions before slaughter content.

Veterinary and sanitary assessment and disinfection of refrigerator chambers of meat processing enterprises

The results of microbiological studies of air samples of refrigerating chambers of meat processing enterprises are presented. The quantitative composition of the air microbiota of the chambers of the refrigerating shop was studied. It has been established that the technological regimes for cooling meat in cooled chambers (t = +4 °C) and deep freezing chambers (t = -18 °C and -22 °C) have no bacteriostatic effect on the life activity of mold fungi. The developed disinfecting preparation (hydrogen peroxide (8.0 - 10%), acetic acid (10%), peracetic acid (5.0 - 7.0%), stabilizing additives, water) ensures the destruction of sanitary-indicative microorganisms in cold rooms meat processing plants when applied at a concentration of 0.05% - 60 minutes, 0.1% - 30 minutes, 0.15% - 10 minutes and does not have a toxic effect on meat raw materials that are stored in chambers of the refrigeration shop after disinfection.

Evaluation of storage methods of beef by microbiological and chemical indicators

Meat and meat products are a major part of a person's ration. However, due to their high nutritional value, they are a favorable environment for the development of microorganisms and require refrigerated storage. The purpose of this work was to evaluate the storage methods for refrigerated and frozen beef by microbiological and chemical parameters and to suggest criteria for evaluating beef by the content of psychrotrophic microorganisms. It was found out that the storage of beef meat with an initial mesophilic bacterial content of about 4.88 log CFU.cm-2 of surface and psychrotrophic bacteria 3.79 log CFU.cm-2 at temperature 0 °C is only possible for 8 days, further, the microbiological indices exceed the acceptable standards. Investigation of the dynamics of microflora reproduction during the storage of beef in the frozen state at temperature -2 to -3 °C for 20 days established a decrease in 1.3 times the number of mesophilic bacteria in 10 days of storage. At the same time, the number of psychrotrophic microorganisms during this storage time was increased in 4.5 times, and 20 days in 7.9 times and amounted to 5.3 log CFU.cm-2 of surface area. This indicates that the storage of meat in the frozen state inhibits or completely stops the development of mesophilic microorganisms for 20 days. It was found out that storing of beef in the cooled state at a temperature of 0 ±0.5 °C for more than eight days is impractical, as its biochemical indices are worsening and signs of spoilage are appearing. At the same time, storing of beef in the frozen state at a temperature of -2 to -3 °C for 20 days does not cause such significant biochemical changes as in beef stored in the cooled state at a temperature of 0 ±0.5 °C for 16 days. Therefore, we have experimentally substantiated the quantitative indicators of the content of psychrotrophic microorganisms on the surface of beef intended for storage in a cooled or frozen state. The proposed microbiological criteria will improve the safety of beef.