Recovering value from beef carcasses classified as dark cutters by USDA graders

¹ Department of Animal Sciences, Colorado State University, Fort Collins, CO 80523
² Department of Statistics, Colorado State University, Fort Collins, CO 80523

^* To whom correspondence should be addressed. E-mail: Keith.Belk{at}Colostate.edu.

	Abstract

Effects of the dark-cutting condition was examined on commercially harvested beef carcass sides which were classified into groups exhibiting 1/3, 1/2, and full degrees of the dark-cutting (DEGDC) condition as evaluated by a USDA-AMS grader (n = 20 per group). Twenty-nine muscles of each carcass side were evaluated to determine ultimate pH and color (L*, a*, and b*). Fourteen beef muscles (biceps femoris, deep pectoral, chuck complexus, gluteus medius, infraspinatus, latissimus dorsi, psoas major, longissimus thoracis, longissimus lumborum, semimembranosus, semitendinosus, triceps brachii long head, tensor fasciae latae, and vastus lateralis) were evaluated using Warner-Bratzler Shear force (WBSF) and a trained sensory panel. The muscle x DEGDC interaction was significant for ultimate pH, L*, a*, and b* values (P < 0.05). When ultimate pH values of individual muscles were compared to the same muscles evaluated in a previous study, the 1/3, 1/2, and full DEGDC had 7, 9 and 5 muscles, respectively, that fell within a computed 95% prediction limit of what would be considered "normal" pH, but were more variable as measured by within class CV's. Color values (L*, a*, and b*) of the muscles from dark-cutting carcasses were numerically lower than those from "normal" carcasses. A survey designed to determine the ideal color range of beef lean for retail meat merchandisers (n = 34) and foodservice chefs (n = 33) across the United States resulted in data analyzed using principle components analysis of L*, a*, and b* values for muscles dissected in the study to estimate true values for dark-cutting carcasses. Muscles that were within an acceptable color value range for foodservice chefs had potential to add between $42.29 to $26.44 and $14.71 to $8.11 per side when valued at Choice and Select prices, respectively. Muscles that were within an acceptable color value range had potential to add between $30.39 to $16.74 and $10.37 to $5.03 per side for retail meat merchandisers when acceptable muscles were valued at Choice and Select prices, respectively. No muscle x DEGDC interactions were detected for WBSF and sensory panel scores (P > 0.05), but differences were detected among muscles (P < 0.05). Several muscles were considered salvageable from the dark-cutting carcasses evaluated and no significant differences in sensory scores or WBSF between DEGDC classes suggested equal sensory expectations for muscles from dark-cutting carcasses.

Key Words: beef, color, pH, value, quality