## 3 Results and Discussion
### Physicochemical Characteristics
Under fresh conditions, CIE L* was the highest in HH3, followed by WRMD 2, WRMD 1, and CB. No marked differences (\(p>0.05\)) in CIE L* were observed between WRMD 1 and CB. In contrast, HH3 and CB exhibited the lowest red color score, whereas WRMD 1 maintained the highest redness score. The CIE a* score of WRMD 2 was higher (\(p<0.05\)) than that of CB and HH3, but was still lower than that of WRMD 1. Moreover, the CIE b* score of WRMD 1 was higher (\(p<0.05\)) than that of other breeds, either fresh or Frozen-Thawed. In contrast, under Frozen-Thawed conditions, CIE L* was the highest in CB, followed by WRMD2, which showed a similar value to HH3 and WRMD1. Frozen-Thawed WRMD 2 and HH3 meats shared similar lightness scores, which were higher (\(p<0.05\)) than that of WRMD 1 meat. Conversely, WRMD 1 maintained the highest redness score, followed by WRMD 2, which showed a similar score to HH3 and CB. All Frozen-Thawed KNC means in this study displayed a higher (\(p<0.05\)) CIE a* score than CB meat. A similar finding was also observed in CIE b*, with the following order from the highest to lowest scores: WRMD 1, WRMD 2, HH3, and CB (\(p<0.05\)). The Frozen-Thawed thigh meat from CB and HH3 maintained a notably more intense red color than the fresh counterpart. No differences in red color score were observed in either WRMD 1 or WRMD 2 meat under fresh conditions (\(p>0.05\)). The frozen-thawing process influences heme pigment homeostasis, wherein myoglobin may be exudated, thus accelerating myoglobin oxidation and consequently altering the color of meat to dull brown [9; 11]. WHC reflects the ability of muscle to retain water during storage and processing, affecting moisture, thawing, and cooking loss [30; 31; 32]. Under fresh conditions, regardless of the chicken breed, the WHC of thigh meat from KNC was lower (\(p<0.05\)) than that of CB meat. In contrast, under Frozen-Thawed conditions, WRMD 2 displayed the lowest WHC value among the KNC breeds (\(p<0.05\)). In addition, fresh chicken thigh exhibited a considerably higher (\(p<0.05\)) WHC percentage than Frozen-Thawed meat, regardless of the chicken breed. [PERSON] et al. [11] reported that the formation of ice crystals during the freezing process was the main reason for the decline in WHC percentage. The penetration  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Variables**} & \multicolumn{2}{c}{**Broiler**} & \multicolumn{2}{c}{**HH3**} & \multicolumn{2}{c}{**WRMD1**} & \multicolumn{2}{c}{**WRMD2**} \\ \cline{2-9}  & **Fresh** & **Frozen-** & **Fresh** & **Thawed** & **Frozen-** & **Fresh** & **Frozen-** & **Fresh** & **Thawed** \\ \hline pH & 6.65 \(\pm\) 0.05 \({}^{\text{Au}}\) & 6.47 \(\pm\) 0.07 \({}^{\text{B}}\) & 6.63 \(\pm\) 0.06 \({}^{\text{Au}}\) & 6.63 \(\pm\) 0.02 \({}^{\text  
of ice crystals into the intracellular environment of the muscle damages the cell membrane, causing moisture and fluid loss during the thawing process. The mean value of meat shear force under freeze-thaw conditions was strongly influenced by the chicken breed. Frozen-Thawed thigh meat from any KNC breed showed a higher (\(p<0.05\)) shear force value (22.05-23.30 N) than that CB meat (17.26 N), indicating a tougher texture. Additionally, a difference (\(p<0.05\)) between the fresh and Frozen-Thawed state was only observed in thigh meat from CB: Frozen-Thawed thigh CB meat maintained a lower (\(p<0.05\)) shear force value than fresh CB meat. Interestingly, the shear force of thigh meat from all KNC breeds under fresh conditions did not change after freezing and thawing. All KNC breeds had higher (\(p<0.05\)) collagen concentrations than CB under fresh conditions. Different slaughtering ages have a strong relationship with the formation of collagen [33]. The average slaughter age of KNC is 12-13 weeks, allowing increased formation of collagen compared to the average slaughter age of CB (5 weeks) [24]. Increased collagen concentration and actin-myosin crosslinks are major contributors to increased shear force [34].