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

Abstract

1. The influence of different rates of wing flapping on the rate of post-mortem glycolysis in the Pectoralis major (PM) muscles of commercially-processed 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 assessed by measuring muscle pH values at 20 min post mortem (pH 20 min ). 2. ES gave a mean pH 20 min value of 6.01, significantly lower than that of the control carcases which had a mean value of 6.45. Within ES treatments, variation in pulse frequency between 1/s and 10/s and in pulse width from 5 to 20 ms had no influence on pH 20 min values as measured by direct probe. However, differences between mean pH 20 min values attributable to pulse 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 commercially-processed broilers stored at chill temperatures for 24 h post mortem . This 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 on its subsequent meat quality assessed after holding the carcases under chill storage conditions for 24 h.