Effect of the Callipyge Phenotype and Cooking Method on Tenderness of Several Major Lamb Muscles1

We conducted three experiments to determine the effects of the callipyge phenotype on the tenderness of several major lamb muscles and to determine the effect of method of cookery on the tenderness of callipyge lamb at 7 d postmortem. In Exp. 1, chops from normal (n = 23) and callipyge (n = 16) carcasses were open-hearth-broiled. Warner-Bratzler shear force values of longissimus, gluteus medius, semimembranosus, biceps femoris, semitendinosus, adductor, and quadriceps femoris were 123, 44, 28, 26, 19, 16, and 13% greater, respectively, for callipyge ( P < .05). In Exp. 2, muscles from normal (n = 18) and callipyge (n = 18) carcasses were oven-roasted. Shear force of triceps brachii was 11% greater for callipyge ( P < .001); however, phenotype did not affect shear force of supraspinatus ( P = .87) or psoas major ( P = .64). In Exp. 3, a trained sensory panel evaluated leg roasts and open-hearth-broiled leg chops from normal (n = 60) and callipyge lamb carcasses (n = 60). Callipyge chops were less tender than normal chops ( P < .05). Regardless of callipyge phenotype, muscles were more ( P < .05) tender when roasted; however, the effect of method of cookery on tenderness scores was greater for callipyge muscles than for normal muscles. Callipyge roasts and normal roasts had similar tenderness ( P = .58), and callipyge roasts were more tender than normal chops ( P < .05). Regardless of cooking method, callipyge samples were less juicy than normal samples ( P < .05). These data demonstrate that the callipyge phenotype will likely reduce consumer satisfaction due to reduced tenderness and juiciness; however, reduced tenderness in callipyge leg muscles could be prevented by ovenroasting.