Sammel, L.M.Hunt, Melvin C.Kropf, Donald H.2010-08-062010-08-062010-08-06http://hdl.handle.net/2097/4519The beef inside round muscle, especially the deep portion, has poor color stability, a troublesome condition for the meat industry. We examined influences of pre-rigor temperature and pH decline on chemistry of the inside (deep) semimembranosus (ISM) and outside (surface) semimembranosus (OSM) in relation to initial color and stability. Cold-boned ISM had a slower chill rate; faster pH decline; more denatured protein; less metmyoglobin reducing ability, oxygen consumption, and water holding capacity; and a lighter, less stable color than the OSM. Cold-boned steaks were two-toned in color and discolored by day 3 of display. Hotboned ISM and OSM chilled at the same rate, had similar pH declines, similar chemical characteristics, and acceptable color traits up to day 5 of display. Techniques that chill the entire beef SM faster produced a more uniform stable color, extended the color life of the ISM, and minimized rework and discounting.BeefSemimembranosusColor stabilityMetmyoglobinReducing activityConference paper