Influence of Marbling and Animal Age on Factors Associated with Beef Quality4

The longissimus dorsi muscle from the loins of 24 Hereford steers and females, 18, 42, and 90-month of age, was studied. The marbling of each carcass was or closely approached either a “slight amount” or “slightly abundant” level. Tenderness of the longissimus dorsi steaks, as measured by the Warner-Bratzler shear and panel tenderness, decreased significantly with increasing animal age. The greatest difference in tenderness was observed between the 18- and 42-month-old animals. The association between marbling and tenderness varied with animal age. “slightly abundant” marbling, as compared to a “slight amount” of marbling, did not enhance the tenderness of steaks from the 18-month-old animals. The more tender steaks from the 42- and 90-month-old animals, however, were associated with the “slightly abundant” marbling level. The effect of aging 14-days varied with animal age, marbling level, and the method of measuring tenderness. Steaks from the 18-month-old animals were influenced little by aging, while those from the 42- and 90-month-old animals were scored more tender by the taste panel after aging 14-days. Measured by the Warner-Bratzler shear, this tenderizing effect of 14-days aging was non-significant. A significant increase in Ph, predominantly in the “slight amount” level marbled cattle 42- and 90-months of age, was noted upon aging 14-days. Taste panel flavor and juiciness scores did not appear to be related to animal age, marbling level, or aging 14-days. Marbling in the steaks did not significantly influence any of the three dimensions of color.