## 3 Results and Discussion  
### Assessment of the Quality of Fresh Fillets  
The results of the visual assessment of hemorrhages in chicken fillets showed that the use of an own-construction (OC) device significantly (\(p<0.01\)) reduced the number of  
Figure 2: Visualization of the brightness of fillet color, varied by the value of the L* parameter. small hemorrhages on the external surface (2 times) and large and small hemorrhages on the internal surface of the fillet (approx. 2.5 and 3.5 times, respectively) compared to the number of hemorrhages in chicken fillets stunned using the PLC device. A much larger number of small hemorrhages (external and internal) occurring in the meat of chickens stunned with PLC may result from an inappropriate selection of the current frequency, which results in an increase in pressure in the blood vessels and capillaries in stressed birds, causing their rupture and, consequently, blood leaking into the surrounding tissues [18; 19]. A significant (\(p<0.01\)) effect of the OC device on the number of hemorrhages in fillets was also confirmed by statistical analysis (Figure 3A). The results of the assessment of fillet defects (Figure 3B) also showed that the use of the OC device allows the production of fillets without defects at a level of approximately 60%, while when using a commercial device (PLC), the production of meat without defects was only 15%. The obtained results confirm the research previously carried out by the authors on the beneficial effect of the own-construction device on the production of high-quality chicken fillets [20] and the reduction of serious and minor meat defects (approx. 50%) in commercial elements of turkey carcasses--fillet, loin, and wing [14; 15] compared to defects occurring using equipment from the Netherlands and Denmark. According to [PERSON] et al. [21; 22], at a higher current frequency (800 Hz), obtaining a smaller number of defects is the result of more effective stunning, i.e., faster and longer loss of consciousness in all birds, which consequently allows for better bleeding and the occurrence of fewer hemorrhages. The use of electric current with a frequency of 400 Hz in the stunning process results in a slightly higher defect of meat than in the case of f = 800 Hz. The results of measuring the pH of fresh meat (pH\({}_{\text{gh}}\)) revealed that the type of device (OC and PLC) and its parameters did not significantly affect the meat's pH, as their values remained at a similar level of approximately 5.90 (Table 1). Taking into account the division into meat quality classes adopted in the literature on the subject, this meat should be considered of good quality (so-called normal, pH = 5.9-6.2). Despite the lack of differences between the pH values of fresh meat, a significant (\(p<0.05\)) effect of the type of device was observed in meat tenderness, determined using the instrumental method. The results of measurements of the maximum puncture force (F\({}_{\text{p}}\)) and deformation (D\({}_{\text{p}}\)) of fillets from chickens stunned using a PLC device showed that their values were on average 27.82 N and 9.32 mm and were higher by approximately 9% and 18% than the values of F\({}_{\text{p}}\) and D\({}_{\text{p}}\) of fillets from chickens stunned using an OC device. We observed a similar relationship, albeit not statistically significant, in the case of cooking loss. As a result of using the PLC device, its average value was approximately 15% and was approximately 2% higher than the value of cooking loss from fillets from chickens stunned using OC (Table 1). This proves the better tenderness and greater juiciness of chicken fillets stunned using the OC device than meat produced using the PLC device. Figure 3: Number of hemorrhages on the external and internal surfaces (**A**) and defectiveness (**B**) of the fillets of chickens stunned using the own-construction (OC) and Polish company (PLC) devices. a–b–significant differences between devices, \(p<0.01\); a–a––no significant differences.