EFFECT OF AGE AND CUT ON CONSISTENCY OF TENDERNESS AND LEANNESS OF BEEF

Longissimus dorsi and Semitendinosus muscles from 180 crossbred steers , representing three age groups and grading Canada A, were evaluated f or consistency in leanness and tenderness. The majority of the carcass es graded Canada Al and received Canada A or AA marbling scores. Post- mortem pH and sarcomere lengths were normal. Percent fat in the muscle samples was not affected by age and few samples exceeded 10% fat. Twe lve month L. dorsi samples were found to be significantly more tender and less chewy than the 24 month samples, as were the 12 month Semiten dinosus samples compared to either the 17 or 24 month samples. Meat fr om 12 month animals was consistently tender but the 17 or 24 month sam ples were not. Chewiness, assessed as 'force X time to chew: identifie d more animals as tough than did tenderness, assessed as 'force to che w', early in the mastication process. Assessment during the later stag es of mastication appeared to be more important In assessing tendernes s of Semitendinosus muscle than L. dorsi.