Effect of some electrical stimulation variables on wing flapping, post-mortem glycolysis and eating quality characteristics of broiler Pectoralis major muscle

1. The influence of different rates of wing flapping on the rate of post-mo rtem glycolysis in the Pectoralis major (PM) muscles of commercially-proces sed broilers was investigated. This was achieved by applying 300 pulses of low voltage electrical stimulation (ES) shortly after slaughter at various frequencies and pulse widths. The rate of post-mortem glycolysis was assess ed by measuring muscle pH values at 20 min post mortem (pH(20 min)). 2. ES gave a mean pH(20 min) a value of 6.01, significantly lower than that of the control carcases which had a mean value of 6.45. Within ES treatmen ts, variation in pulse frequency between 1/s and 10/s and in pulse width fr om 5 to 20 ms had no influence on pH(20 min) values as measured by direct p robe. However; differences between mean pH(20 min) values attributable to p ulse frequency were detected when measured by the iodoacetate method. 3. A further experiment was carried out to determine how different rates of wing flapping would affect the eating quality of PM muscles from commercia lly-processed broilers stored at chill temperatures for 24 h post mortem. T his was achieved by using pulse frequencies of 1/s, 5/s and 10/s, all other ES variables being standardised. Pulse frequency had no effect on ultimate pH, sarcomere length, cooking loss or tenderness of PM muscle compared to controls. 4. We concluded that the rate of wing flapping post-slaughter has no effect , per se, on the extent of post-mortem glycolysis in broiler PM muscle or o n its subsequent meat quality assessed after holding the carcases under chi ll storage conditions for 24 h.