## 3 Results and Discussion
### Assessment of Technological Quality of Stored Meat  
Chilled meat will be the basic form of selling meat products in the future, so it is important to guarantee high-quality meat already at the stage of slaughtering animals and then during storage [29]. The ability to manage the quality of chilled meat in segments of the processing chain and customer deliveries [11] will allow for sustainable management of the production of packaged meat. Therefore, the study aimed to assess the technological suitability of refrigerated meat storage, considering changes in pH, tenderness, cooking loss, and color. The results of meat pH measurements during storage revealed that the use of the OC device had an insignificant effect on the meat's pH values, which varied in the range of 5.90-6.00. When the PLC device was used, significant changes (\(p<0.05\)) in the pH of the meat during storage were observed. For 12 days of storage, the pH values increased in the range of 5.90-6.08, then on the 14 th day they decreased to 5.88. An analysis of the impact of the type of appliance used revealed that this factor differentially affects the pH of meat in the final storage period (12 and 14 days). The observed trends testify to the beneficial effect of the OC device on the quality of meat, while a decrease in the pH value to 5.88 in the final period of its storage (Table 3), in the case of the use of the PLC device, may indicate the process of protein denaturation already taking place in meat [30]. To identify the direction of changes occurring in the meat during storage, an instrumental fragility assessment was carried out, which is a function of the biochemical properties of the muscles in the time after slaughter and the rate and severity of the development of post-mortem concentration [31]. The meat tenderness tests showed that the maximum puncture force (F\({}_{\text{P}}\)) of the fillets of chickens stunned using the OC device dropped to about 23 N after 7 days of storage \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multicolumn{2}{c}{**Time of Storage**} & \multirow{2}{*}{**Type of Device**} & \multirow{2}{*}{**pH**} & \multirow{2}{*}{**F\({}_{\text{P}}\)[N]**} & \multirow{2}{*}{**D\({}_{\text{P}}\)[mm]**} & **Cooking Loss [\%]** \\ \hline \multirow{3}{*}{7} & OC & 5.86 \(\pm\) 0.02 & 22.96 \(\pm\) 5.21 \({}^{\text{A}}\) & 8.50 \(\pm\) 0.58 \({}^{\text{a}}\) & 12.91 \(\pm\) 0.68 \\ \cline{2-6}  & PLC & 5.81 \(\pm\) 0.06 & 27.82 \(\pm\) 7.28 \({}^{\text{B}}\) & 9.92 \(\pm\) 1.14 \({}^{\text{b}}\) & 13.44 \(\pm\) 0.11 \\ \hline \multirow{3}{*}{9} & OC & 5.92 \(\pm\) 0.12 & 21.94 \(\pm\) 2.95 & 8.02 \(\pm\) 1.28 & 17.76 \(\pm\) 3.64 \\ \cline{2-6}  & PLC & 6.08 \(\pm\) 0.10 & 20.95 \(\pm\) 3.51 & 7.55 \(\pm\) 1.29 & 17.13 \(\pm\) 1.42 \\ \hline \multirow{3}{*}{12} & OC & 5.92 \(\pm\) 0.10 \({}^{\text{a}}\) & 22.65 \(\pm\) 3.24 & 8.26 \(\pm\) 1.05 & 17.69 \(\pm\) 2.85 \\ \cline{2-6}  & PLC & 6.16 \(\pm\) 0.13 \({}^{\text{b}}\) & 22.55 \(\pm\) 2.68 & 8.50 \(\pm\) 0.98 & 19.83 \(\pm\) 0.48 \\ \hline \multirow{3}{*}{14} & OC & 6.00 \(\pm\) 0.06 \({}^{\text{b}}\) & 22.89 \(\pm\) 3.27 & 8.19 \(\pm\) 1.26 & 17.43 \(\pm\) 0.55 \\ \cline{2-6}  & PLC & 5.88 \(\pm\) 0.09 \({}^{\text{a}}\) & 22.75 \(\pm\) 2.93 & 8.20 \(\pm\) 1.04 & 14.95 \(\pm\) 1.84 \\ \hline \multirow{3}{*}{Analysis of variance, variable storage time} & OC & NS & NS & NS & NS \\ \cline{2-6}  & PLC & * & ** & ** & * \\ \hline \hline \end{tabular}  
* \({}^{\text{a}}\)–significant differences between rows (devices), \(p<0.01\), \({}^{\text{A}}\)–significant differences between rows, \(p<0.05\); \({}^{\text{**}}\)–significant differences, \(p<0.01\); \({}^{\text{a}}\)—significant differences, \(p<0.05\), NS—no significant differences.
* \({}^{\text{b}}\)–significant differences, \(p<0.01\); \({}^{\text{a}}\)—significant differences, \(p<0.05\), NS—no significant differences.  
\end{table}