Influence of Carcass Maturity and Marbling on the Physical and Chemical Characteristics of Beef. I. Palatability, Fiber Diameter and Proximate Analysis

Abstract

Eighty beef ribs representing four maturity levels, (A, B, C and D) and two marbling levels (slight and moderate) were used in this study. Neither maturity, marbling, nor core location had a significant effect on tenderness as determined by the Warner-Bratzler shear. Steaks from the longissimus dorsi of the more mature carcasses were generally considered less tender than those from less mature carcasses by a taste panel. The taste panel could detect no differences in tenderness due to marbling or sample location. The flavor of the steaks from the less mature carcasses was generally preferred by the panel. Steaks containing a moderate amount of marbling were significantly more juicy than those containing a slight amount. Muscle fiber diameters were significantly (P<.01) larger in the moderate marbling group than in the slight group. A trend toward larger fiber diameters was noted for the muscle fibers from the more mature carcasses. The A maturity protein percents were significantly lower than those of the B, C and D groups. The moderate marbling level had significantly (P<.01) more fat and less moisture than the slight level. The slight level had significantly more protein. Shear and taste tests were significantly correlated. Fiber diameter was not significantly correlated with tenderness.