Comparison of Postmortem Handling Methods for Effects on Quality Characteristics of Mature Beef

The longissimus, semitendinosus and semimembranosus muscles from 60 U.S. Utility beef carcasses were used to investigate the effects of electrical stimulation (ES), different postmortem boning times, blade tenderization coupled with enzyme dip, and storage conditions on the quality, appearance, cooking and sensory properties of cooked beef muscle. Muscles were removed from stimulated and nonstimulated sides at 1, 3 or 24-h Postmortem, wrapped in PVC film and either immediately frozen at -40°C or stored at 2 to 3 C for 24 h and then frozen at -40°C. Before freezing, part of the muscles was allocated to blade tenderization and/or enzyme dip treatments while the remainder served as controls. Electrical stimulation increased tenderness in muscles excised at 1 h postmortem; however, as boning time increased, the effects of ES on tenderness decreased. It was concluded that electrical stimulation increased tenderness sufficiently to allow boning at 1 or 3-h postmortem. Blade tenderization and/or enzyme dip treatments did not significantly improve tenderness of any of the muscles over the effects of ES. With the exception of the semitendinosus, muscles chilled 24 h before freezing were significantly (P<.05) more tender than those frozen immediately.