## 3 Results and Discussion
### Assessment of Technological Quality of Stored Meat
The a* values of the tenderloin of chickens stunned with the PLC device and stored for 7, 9, and 14 days were higher by approximately 39.94, 29.56, and 20.30%, while when stored for 12 days, they were 7.5% lower than the corresponding a* values of chicken tenderloin  
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \multirow{2}{*}{**Time of Storage [Days]**} & \multirow{2}{*}{**Type of Device**} & \multicolumn{6}{c}{**m.pectoralis major (PMj)**} & \multicolumn{6}{c}{**m.pectoralis minor (PMn)**} \\ \cline{3-10}  & & & \multicolumn{2}{c}{**Earternal Surface—ES**} & \multicolumn{2}{c}{**Internal Surface—IS**} & \\ \cline{3-10}  & & & **L* & **a* & b* & **L* & **a* & b* & **L* & **a* & b* \\ \hline \multirow{4}{*}{7} & \multirow{2}{*}{OC} & 65.25 \(\pm\) & 2.76 \(\pm\) & 15.53 \(\pm\) & 63.10 \(\pm\) & 2.63 \(\pm\) & 17.3  
stunned using the OC device. The b* values of the color of chicken tenderloin stunned using the PLC device and stored for 7 and 14 days were higher by 0.73 and 2.68%, while those stored for 9 and 12 days were lower by 8.94 and 8.51% compared to the a* value of chicken tenderloin stunned with the OC device (Table 4). Summarizing the obtained results of color parameter tests and their statistical analysis, it was found that the lightness--L* of the meat color (fillets, tenderloins) of chickens stunned using the OC device was higher than when using the PLC device, and the storage time had a significant effect (\(p<0.01\)) on its changes (Table 4). The greater lightness of the meat color may result from the decreasing water-holding capacity, especially as a result of increasing water loss during thermal processing (Table 4). According to [PERSON] et al. [30], poor water holding capacity is caused by the presence of more liquid on the surface of the meat, which enhances light reflection. Denaturation of proteins during storage causes light to pass through the meat tissue and changes the way it is scattered compared to the normal refractive behavior of proteins. Significant differences (\(p<0.01\)) between the brightness and saturation of red and yellow meat in chickens stunned with OC and PLC were observed mainly after 9 and 12 days of storage, with an inverse relationship between changes between the values of parameters a* and b*. Significant differences in changes in meat color parameters of chickens stunned using the PLC device were observed only in the case of parameters a* (ES fillet, \(p<0.05\)) and b* (IS fillet, \(p<0.01\) and tenderloin, \(p<0.01\)). The results of research by other scientists have shown that the saturation of the red color (b*) is influenced by voltage [9; 36] and current intensity [7], while the saturation of the yellow color has no significant influence: frequency [37], voltage [36], intensity [7], and the electrical stunning method [9; 38]. According to [PERSON] et al. [39], in the meat of broilers stunned with a higher current frequency (650 Hz), a higher yellowness value was obtained compared to broilers stunned with a low current frequency (300 Hz). As a result of the PROFILE analysis--multidimensional scaling and Euclidean distance, eleven features characterizing chicken meat were reduced to two dimensions. As a result of these activities, each of the examined features received two coordinates, thanks to which it was presented in the form of a two-dimensional perception map. The value of the \"Stress\" coefficient for multidimensional scaling, taking into account all features, was 0.00036; therefore, the scaling procedure was reliable. Parameters of the regression function (b\({}_{0}\), b\({}_{\text{Dim.1}}\), b\({}_{\text{Dim.2}}\)), in which the explained variable were meat parameters and the explanatory variables--the values of two dimensions for each object.