Physical, Chemical and Palatability Traits of Electrically Stimulated, Hot-boned, Vacuum-packaged Beef

The right sides of six beef carcasses were electrically stimulated, whereas the left sides were not so treated. Sections of longissimus and semimembranosus muscles were removed from electrically stimulated sides at 1 h postmortem (hot-boned) and from sides which were not electrically stimulated at 24 h postmortem (conventionally boned); these muscles were vacuum-packaged immediately after removal and aged for 2 weeks at 1 ± 1 C. After aging, steaks were removed and used for determinations of palatability, cooking loss, pH, sarcomere length and protein solubility. Further evaluation included purification and electrophoresis of myofibrillar proteins. Longissimus muscles from electrically stimulated, hot-boned beef had lower (P < .05) juiciness ratings than those from conventionally handled sides; semimembranosus muscles from electrically stimulated, hot-boned sides sustained lower (P < .05) weight losses during storage but higher (P < .05) cooking losses than muscles from conventionally handled sides. Hot-boning of electrically stimulated beef had no effect (P > .05) on tenderness, flavor desirability, pH, sarcomere length, amount of non-protein nitrogen or percentage of soluble myofibrillar proteins; slight alterations were noted in the electrophoretic banding patterns, on SDS gels, of myofibrillar proteins from electrically stimulated. hot-boned sides. Hot-boned beef was as palatable as conventionally handled beef if sides were electrically stimulated on the kill floor before hot-boning and if beef from both treatments was vacuum packaged and aged for 2 weeks at 1 ± 1 C.