Post-mortem glycolytic and physical changes in turkey breast muscle

The concentration of glycolytic intermediates and co-factors in and pH values of P. superficlalis muscles from each of five 15 week-old and five 25 week-old White Cannon torn turkeys was measured at varying times between 0 and 180 min. post-mortem. Different rates of post-mortem glycolysis were evident among birds, independent of age. On the basis of ATP catabolism, pH and lactic acid accumulation, two groups categorized as "fast-" and "slow-glycolyzing" were evident. The different rates of glycolysis could not be explained by qualitative or quantitative differences in control of the glycolytic flux. The patterns of change in concentration of intermediates and co-factors expressed as mass action ratios suggested that regardless of glycolytic rate, post-mortem glycolysis in turkey breast muscle is susceptible to control at the reactions catalyzed by hexokinase, phosphofructo kinase, aldolase and triosephosphate isomerase, glyceraldehyde phosphate dehydrogenase and phosphoglycerokinase and pyruvate kinase. P. superficialis muscles from six 19 and six 27 week-old White Cannon torn turkeys were analyzed for ATP concentration at "0" and "60" min. post-mortem and muscle pH was determined during a three hour post-mortem period. The time required for excised muscle strips to achieve maximum contraction was determined by periodic measurement of strip length. Analysis of the data indicated a relationship between rate of ATP catabolism and time to maximum contraction. "Slow-" and "fast-glycolyzing" groups were evident and were independent of age. The "slow-glycolyzing" group had a higher initial ATP concentration, a larger proportion of initial ATP remaining at 60 min. and required a longer time for the muscle strips to achieve maximum contraction.Land and Food Systems, Faculty ofGraduat