Recently, there has been an increase in the incidence of pale soft and exudative poultry meat. Pale, soft, and exudative (PSE) meat is caused by a decline in pH early postmortem while carcass temperatures are still high. This decrease in pH leads to protein denaturation attributing to the pale color and poor water holding capacity (WHC) that is characteristic of this lesser quality meat. Pale, soft, and exudative meat has economic implications for processors with losses ranging between $2-4 million each year. Marination with salt and phosphates has been shown to improve protein functionality, thereby reducing lost meat yield and improving meat color, WHC, and texture. However, there are few studies relating marination with phosphates to improvements in PSE meat. Therefore, the purpose of this study was to determine if color, WHC, and texture improvements could be obtained in PSE meat via marination with various phosphate and NaCl treatments without altering the quality and oxidative stability of normal or PSE meat. In Experiment 1, 12 phosphates were evaluated for improvements in pH, color, and WHC of PSE meat. From these, five phosphates were chosen based on pH, color, and WHC improvements for Experiment 2. The marinades used in Experiment 2 increased the pH, decreased the L* values of the pale fillets, and improved water holding capacity. Thiobarbituric acid-reactive substances, sensory, and microbial analysis studies concluded that marination with high pH phosphates can reduce the undesirable characteristics of PSE meat without increasing the development of oxidation, altering flavor, or reducing shelf-life. / Master of Science

Comparison of pig?s stunning (by electricity or CO2) at slaughterhouse and monitoring the occurrence of quality variance PSE during 48 hours post mortem was main goal of this work. Basic indicators such as pH1, drip loss of water and meat colour (lightness) were determined to assess PSE. In addition to these indicators have been also evaluated values of pH24 and pH48. The result of those indicators is that during stunning by CO2 gas value of pH1 was higher by 0,3 degree (P < 0,001), value of pH24 was higher by 0,243 (P < 0,001) and average drip loss of water was lower by 2,16 % (P < 0,001). Changes in other evaluated indicators were statistically non-significant. Occurrence of quality variance which tends to PSE (PSEi) and PSE was evaluated at slaughterhouse which is using electricity for stunning as higher by 7,843 % at PSEi and 1,961 % at PSE based on value of pH1. As higher was evaluated also drip loss of water by 23,810 % at PSEi respectively 4,762% at PSE. Difference between occurring of PSEi and PSE based on meat colour was not observed. The highest correlation dependence was found between pH1 and drip loss of water (r = 0,586, R2 = 34,315 %).

This diploma thesis follows the bachelor thesis and it?s task is to processing analysis of the occurrence of PSE meat in a population of the Czech white breed as a pigs stress syndrome impact. General problem of congenital diseases is processed in literature review. Further, this work deals with pigs stress syndrome and stress, which causes the meat defects as an external factor. Molecular - genetic methods, which are used in the practical part, are described as well. The research focused on genotyping of loci selected panel of samples, to determine the frequency of alleles and genotypes of selected locus and the statistical relationship between genotype and expression of PSE meat. Results were statistically processed and evaluated at the end.