Effects of Electric Treatments and Wing Restraints on the Rate of Post-Mortem Biochemical Changes and Objective Texture of Broiler Pectoralis Major Muscles Deboned After Chilling

ABSTRACT The study was conducted to determine the effects of electric current and wing restraints on the rate of post-mortem biochemical changes and objective texture of broiler Pectoralis major muscles deboned after chilling. Electric treatments of stun, stun and stimulate, and electrocution were ad-ministered to a total of 12 birds in each of six replications of the study. In each replication, wing restraints were applied to two of the four birds subjected to each electric treatment. Birds were subjected to the stunning and electrocution treatments prior to bleeding for 90 s. For the stun and stimulation treatment, the birds were bled during and after the pulsed stimulation. Carcasses were subjected to the wing restraints after feather removal, then eviscerated, prechilled, and chilled. The Pectoralis major muscles were removed 75 min post-mortem and evaluated for pH, R value (ratio of adenine to inosine nucleotides), and sarcomere length. Muscles were held at 2 C for 24 h prior to cooking and objective texture evaluation. Stunning and stimulating treatments resulted in significantly higher R values and lower pH values compared with the electrocution treatment. The application of wing restraints significantly increased sarcomere lengths in raw deboned muscle. Stunning followed by pulsed stimulation in conjunction with wing restraints resulted in the lowest shear values (5.95 kg) for cooked meat of muscles deboned 75 min post-mortem. {Key words: electric stimulation, electrocution, wing restraints, sarcomere lengths, meat texture) 1993 Poultry Science 72:1577-1583 ensure ultimate texture or tenderness in the cooked meat. The use of pulsed electric current applied to the carcass shortly after death has been studied by several researchers (Thompson et al, 1987