Influence of Hot-Boning, Cooking and Method of Reheating on Product Attributes of Lamb Roast ¹

Ten lamb carcasses were used to evaluate the effects of hot-boning (HB), cooking, freezing and method of reheating upon cooking and palatability attributes of lamb roast. After slaughtering, the leg and loin were removed (30 min post-exsanguination) from the right side and cooked immediately (HB), while the left side was fabricated 5 d later (cold boned, CB) and cooked until the internal temperature reached 68°C. The roasts were frozen and stored for about 45 d. Roasts were thawed (2°C), and pre-cooked roasts were divided into similar portions and assigned to three reheating methods: (a) conventional electric oven (b) microwave oven and (c) a combination method where the first half of the cooking time was by conventional roasting and the second half by microwave oven. Results indicate HB roasts had higher (P<.05) cooking losses, thaw losses and reheating losses (3%) than CB roasts. HB leg roasts required less (P<.05) time to cook than CB, but no difference (P>.05) was found for the loin roasts. Conventional oven reheating resulted in higher thaw and reheating losses, and a longer reheating time than microwave reheating or the combination method. The shear values for HB muscles of the leg were lower, in most instances, than those for CB muscles of the leg. Panel tenderness scores indicated that pre-cooked, conventional reheated HB, semimembranosus (SM) and CB, SM, were more tender than the SM reheated with a microwave oven. All the precooked, reheated products were of acceptable palatability.