Tenderization of Early-Harvested Broiler Breast Fillets by High-Voltage Post-Mortem Electrical Stimulation and Muscle Tensioning,

Abstract Three experiments, each composed of two 96-bird trials, were conducted to determine the effects of electrical stimulation (ES) and muscle tensioning (MT) on tenderness, sarcomere length, and pH of broiler Pectoralis fillets harvested from chilled carcasses 1 h post-mortem (chill-boned). Shear values of fillets from ES carcasses were significantly lower than unstimulated controls, with no significant difference for ES duration. There were no significant differences between the sarcomere lengths of raw fillets from any of the ES treatments, but all had significantly longer sarcomeres than did the unstimulated controls. Muscle tensioning significantly improved the tenderness of chill-boned breast fillets compared with that of nontensioned carcasses, with no significant differences between any of the MT initiation times. Sarcomeres of all tensioned carcasses were significantly longer than nontensioned controls, with no significant difference between any of the MT treatments. When ES and MT were applied in combination, their interaction resulted in significantly lower shear values compared with either individual treatment. The mean sarcomere length for the combined ES and MT treatment was significantly longer than that of untreated control carcasses or those receiving either treatment. Electrical stimulation, but not MT, increased the rate of post-mortem pH decline. The combined ES and MT treatment increased the percentage of fillets harvested at 1 h post-mortem that would be considered tender by consumers.