Biochemical and histological considerations of age-related traits affecting bovine muscle tenderness

Biochemical and histological considerations of age-related traits which affect bovine muscle tenderness were assessed from muscles obtained form 40 carcasses from cattle of known chronological age. These cattle ranged in age from 12 months to 27 years of age at the time of slaughter. All cattle were stratified into three groups based on chronological age at slaughter: Group I = 305-1033 days; Group II = 1332-2927 days; and Group III = 3635-9828 days. The palatability of the cooked longissimus muscle was evaluated by a trained sensory panel and shear force requirements were determined for the longissimus, biceps femoris and semiembranosus muscles. No significant differences among samples form carcasses in the three age groups were observed for juiciness ratings, tenderness ratings or shear force values. Samples from animals in age group I possessed significantly higher percentages of moisture and soluble collagen than those from animals in either age group II or III. Juiciness ratings were not significantly associated with chronological age at slaughter or to any of the measures of tenderness (subjective or objective). Initial tenderness ratings were closely related to sensory panel ratings for muscle fiber tenderness and amount of connective tissue in all of the groups studied. ..