The Influence of Postmortem Electrical Stimulation on Rigor Mortis Development, Calpastatin Activity, and Tenderness

ABSTRACT This study was conducted to evaluate the effects of electrical stimulation (ES) on rigor mortis devel-opment, calpastatin activity, and tenderness in anatomi-cally similar avian muscles composed primarily of either red or white muscle fibers. A total of 72 broilers and 72 White Pekin ducks were either treated with postmortem (PM) ES (450 mA) at the neck in a 1 % NaCl solution for 2 s on and 1 s off for a total of 15 s or were used as nonstimulated controls. Both pectoralis muscles were har-vested from the carcasses after 0.25, 1.25, and 24 h PM and analyzed for pH, inosine:adenosine ratio (R-value), sarcomere length, gravimetric fragmentation index, cal-pastatin activity, shear value, and cook loss. All data were analyzed within species for the effects of ES. Electrically stimulated ducks had a lower muscle pH at 0.25 and 1.25 h PM and higher R-values at 0.25 h PM compared with controls. Electrically stimulated broilers had a lower mus-(Key words: electrical stimulation, rigor mortis, meat, tenderness, muscle fiber types