Bloom Development of the Beef Semimembranosus and Triceps Brachii as Influenced by Wet-Aging

The semimembranosus (SM) and triceps brachii (TB) from USDA Select beef carcasses were used to test the effect of wet-aging period on bloom development. Inside rounds (IMPS#168) and shoulder clods (IMPS #114) were randomly allocated to 0, 7, 14, 21, 28, and 35 d wet-aging at 2°C (n = 10 subprimal cuts/aging period). Each week, two 2.54-cm-thick, non-adjacent steaks were cut from aged inside rounds and shoulder clods, and instrumental color (L*, a*, and b*) of the SM and TB was measured at 10-min intervals for 2 h after cutting. Steaks from the SM and TB became a more vivid (greater C* values; P < 0.05), redder (greater a* values; P < 0.05), and yellower (greater b* values; P < 0.05) color during the 120-min bloom period. Moreover, the calculated proportion of oxymyoglobin (OMb) in SM and TB steaks increased (linear, P < 0.001) during the first 80 min after cutting but stabilized thereafter. Redness (a* and hue angles), b*, and C* values decreased (linear, P ≤ 0.050) in SM steaks as duration of wet-aging increased from 0 to 35 d, but length of wet-aging had no (P ≥ 0.127) effect on instrumental color measures of TB steaks. Neither the percentage of calculated OMb (P = 0.580) nor OMb asymptotic point (P ≥ 0.214) for SM steaks was affected by duration of wet-aging, and, even though the proportion of OMb in TB steaks was not altered (P = 0.459) by postmortem aging, OMb asymptotic points increased (linear, P = 0.001) in TB steaks with increasing durations of wet-aging. Results of these experiments indicate that 90%, or more, of the change in color was achieved within the first 50 to 60 min after cutting, but duration of wet-aging had little to no impact on bloom development in SM and TB steaks.