Effect of blade tenderization, aging time, and aging temperature on tenderness of beef longissimus lumborum and gluteus medius.

Purveyors are concerned about the po- tential food safety risk of nonintact meat products and are seeking strategies to ensure adequate meat tender- ness without blade tenderization. This study was con- ducted to determine the effects of blade tenderization and time and temperature of aging on beef longissimus lumborum (LL) and gluteus medius (GM) tenderness. Beef strip loins (n = 300) and top sirloin butts (n = 300) were assigned to storage at −0.5 or 3.3°C for 12, 26, or 40 d. Cuts were blade tenderized (BT) or not blade tenderized (NBT) before steak cutting. One 2.54- cm steak from each subprimal was used for slice shear force determination and Western blotting of desmin. Desmin degradation was less (P 0.05) slice shear force values of BT LL steaks (10.4, 9.9, and 9.4 kg for 12, 26, and 40 d aging, respectively), but reduced (P 0.05) slice shear force values of BT LL steaks (10.2 and 9.6 kg for steaks aged at −0.5 and 3.3°C, respectively), but improved (P < 0.05) slice shear force of NBT LL steaks (15.1 and 12.4, respectively). Aging at 3.3°C increased (P < 0.05) proteolysis in GM steaks (43 and 54% for −0.5 and 3.3°C, respectively). Longer aging times increased (P < 0.05) proteolysis (40, 46, and 60% for 12, 26, and 40 d aging, respectively) in GM steaks. Blade-tenderized GM steaks had dramatically less (P < 0.05) slice shear force values than NBT steaks (13.7 and 19.9 kg, respec- tively). Raising aging temperature from −0.5 to 3.3°C reduced (17.6 vs. 16.0 kg; P < 0.05) and increasing ag- ing time from 12 d to 40 d improved (17.9 vs. 15.2 kg; P < 0.05) slice shear force values of GM steaks. Blade tenderization and increased aging time and tempera- ture all improved tenderness of beef LL and GM steaks, though blade tenderization provided greater improve- ments than increased aging time and temperature. Lon- ger aging could potentially be used to replace blade tenderization for LL steaks, but not in GM steaks.