Association of Serum Glucose, Serotonin, Aspartate Aminotransferase, and Calcium Levels with Meat Quality and Palatability Characteristics of Broiler Pectoralis Major Muscle

SIMPLE SUMMARY: Apoptosis is a critical and highly regulated cell death process after exsanguination, and serum apoptosis-related molecules are associated with apoptotic and glycolytic potentials. Thus, the activities and production of these molecules can directly and/or indirectly affect variation in meat quality characteristics. However, there is limited information on the complex relationship between serum biochemical molecules and their effects on the meat and eating quality of broilers. In the present study, the activity of aspartate aminotransferase, a cytoprotective molecule, was found to be associated with other apoptosis-related molecules, including blood glucose, serotonin, and calcium levels, at exsanguination. All serum parameters analyzed in this study were related to the early postmortem and ultimate muscle pH. Thus, apoptosis-related molecules may affect the glycolytic rate in broiler pectoralis major muscle. Additionally, our results demonstrated that the variations in the sensory quality traits of broilers could be somewhat explained by the levels of apoptosis-related serum parameters at exsanguination. ABSTRACT: This study investigated the correlations between apoptosis-related blood biochemical parameters measured at exsanguination and the meat and sensory quality characteristics of broiler pectoralis major muscle. The concentration of serotonin showed a positive correlation with aspartate aminotransferase (AST) activity (p < 0.001) and a negative correlation with calcium content (p < 0.01). All serum parameters showed relationships with muscle pH at 15 min and/or 24 h postmortem (p < 0.05). Serum AST activity, which had a negative correlation with calcium content (p < 0.01), was positively related with muscle pH and negatively correlated with Warner–Bratzler shear force values (WBS, p < 0.05). Principal component analysis results revealed the associations between AST activity and meat quality traits, including pH(24h), lightness, and WBS. Furthermore, cooked breast with higher AST activity and lower calcium level tended to exhibit higher scores of tenderness and overall acceptability than that with lower AST activity and higher calcium level (p < 0.05).