Muscle-specific effect of aging on beef tenderness

Tenderness is a muscle-specific trait critically influencing consumers’ acceptance of beef and overall eating satisfaction. Muscles in a beef carcass differ in their biochemical properties and thus may respond differentially to postmortem aging. Therefore, the objective of the current study was to examine the effect of aging time on tenderness of beef longissimus lumborum (LL), psoas major (PM), and semitendinosus (ST). The LL, PM, and ST muscles obtained from eight (n = 8) beef carcasses were subjected to aging for 0, 7, 14, or 21 days, and tenderness was evaluated instrumentally. Muscle source and aging days influenced (P < 0.05) the tenderness, with aging improving (P < 0.05) the tenderness. Moreover, a muscle x aging day interaction (P < 0.05) was observed for tenderness. Tenderness in LL improved until 21 days, whereas in PM and ST improvement was observed until 7 and 14 days, respectively. Additionally, by day 21, LL was the most (P < 0.05) tender, while ST remained the toughest (P < 0.05). Fabrication of beef sub-primals to individual muscles before aging could facilitate optimizing the duration of aging. Furthermore, beef industry may utilize muscle-specific aging strategies to improve tenderness.