Comparison of Assays for Metmyoglobin Reducing Ability in Beef Inside and Outside Semimembranosus Muscle

The relationships of 6 assays for metmyoglobin (Metmb) reducing ability to color stability and the chemical differences between the inside (ISM) and outside (OSM) beef semimembranosus (SM) muscle after 5 or 14 d storage were investigated. The ISM had less (p < 0.05) color stability than the OSM regardless of time post mortem, and both muscle portions were more color‐stable when stored for 5 d rather than 14 d. Among the assays, aerobic reducing ability correlated best with visual color scores (r =−0.58) and Metmb accumulation (r =−0.61) in the SM. The ISM had less reducing ability than the OSM, which can be attributed partially to lower oxygen consumption rate and NAD concentrations (p < 0.05).