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 (PMI) 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.

Acompanhamento das alterações post-mortem (Glicólise) no músculo do jacaré do pantanal (Caiman crocodilus yacare)

“…As medidas de pH foram realizadas pelo método de iodoacetato, como no presente trabalho com o jacaré. Os resultados obtidos mostraram que a variação da intensidade elétrica no atordamento não teve nenhum efeito na glicólise e na qualidade da carne estocada sob refrigeração [7].…”

Effect of Electrical Stimulation on Qualitative Characteristics of Aged Chicken Carcasses: A Comprehensive Review

“…Stimulation of electrically slaughtered boiler meat with a voltage of 50 didn't improved tenderness of flanged muscles when cuts values as well as values of tenderness and juiciness were measured (Lyon et al, 1989). Gault et al (2000) came to point that stimulation of electrically slaughtered boiler meat with a low voltage (100) decreased the pH for chest muscles with an amount of 0.5 units following 20 minutes of slaughter, whether pH was measured by using Iodoacetate or direct connection of an electrode to the muscle .…”

“…It was shown by the pH values that the electrical stimulation accelerated the development of rigor mortis by lowering the pH due to the accumulation of lactic acid in the muscles as a result of the process of diabetic decomposition. Most researchers noted that there was a significant fall in pH values when electrical stimulation was applied to laying hens (Gault et al, 2000), turkeys (Kannan et al, 1991) and broiler and ducks (Alvarado & Sams, 2000).…”

“…Pectoralis major from broilers subjected to the 350 V stimulation treatment exhibited the lowest cooked yield and the greatest percentage of fluids and solids lost during heating than samples from broilers subjected to 50 V stimulation. There was no significant difference in cooked yield or percentage loss of fluids and solids for breast meat from carcasses subjected to the 50 or 200 V. Gault et al (2000) investigated the influence of different rates of wing flapping on the rate of post-mortem glycolysis in the pectoralis major of commercially-processed broilers. Broiler carcasses were treated with 300 pulses of low voltage electrical stimulation shortly after slaughter at various frequencies and pulse widths.…”

Gas composition in controlled atmosphere stunning affects turkey meat quality traits

“…In CAS, increasing the amount of inert gas at the expense of CO 2 has been shown to cause more severe muscle convulsions during stunning and bleeding (Gerritzen et al, 2000;McKeegan et al, 2007b), as was also the case in the present study (unpublished results). A connection between severe wing flapping during anoxic stunning and rapid pH decrease has been proposed in many (Raj et al, 1990b;Poole and Fletcher, 1995) but not all (Gault et al, 2000) studies. Furthermore, the results of Papinaho et al (1995) and Northcutt et al (1998) suggest that the delay to early post mortem pH decrease caused by electrical stunning or CO 2 stunning is primarily a function of the elimination of peri-mortem struggle.…”