RELATIONSHIP BETWEEN SHEAR FORCE AND TRAINED SENSORY PANEL TENDERNESSRATINGS OF 10 MAJOR MUSCLES FROM BOS-INDICUS AND BOS-TAURUS CATTLE

The present experiments were conducted to determine 1) the relationshi p between shear force and overall tenderness of 10 major beef muscles, 2) the effect of Bos indicus inheritance on the tenderness of various beef muscles, 3) whether differences in tenderness between genotype a re affected by method of cookery, and 4) the relationship between tend erness of the longissimus and tenderness of other muscles. To meet the first objective, shear force and trained sensory panel overall tender ness were determined for psoas major (PM), infraspinatus (IS), triceps brachii (TB), longissimus (LD), semitendinosus (ST), gluteus medius ( GM), supraspinatus (SS), biceps femoris (BF), semimembranosus (SM), an d quadriceps femoris (BF) steaks from grain-fed steer carcasses (n = 1 6). Shear force did not accurately reflect differences among muscles i n overall tenderness. To accomplish the remaining objectives, muscles were removed from grain-fed Bos taurus x Bos taurus (n = 31) and Bos i ndicus x Bos taurus (n = 18) steer carcasses and aged until 14 d postm ortem. Shear force of LD, TB, SS, BF, and QF steaks and QF, BF, TB, an d LD roasts was higher(P <.05) for progeny of Bos indicus sires than f or progeny of Bos taurus sires. Shear force differences among genotype s were reduced slightly by roasting. Shear force of LD was not highly related to shear force of other muscles. Thus, systems that accurately predict the tenderness of LD of a carcass will likely do Little to pr edict the tenderness of other muscles.