THE BASAL TOUGHNESS OF UNAGED LAMB

Identification of the commencement of aging in relation to the rigor p rocess was determined on lamb loin muscles by injecting a zinc-TRIS so lution, which inhibits meat aging, into the muscle over the period whe n the pH was falling. Aging was evaluated by measuring the tenderness of cooked meat samples using a MIRINZ tenderometer. When zinc was inje cted into muscle above pH 6.5, the sarcomeres shortened and the cooked meat had an average shear force of 19 kgF (shear force is the force r equired to shear through at 1 cm cross-section sample). When zinc was injected into the muscle at pH values below 6.5 the sarcomers did not shorten, and down to the ultimate pH, the shear force remained at appr oximately 15 kgF. Aging did not take place pre-rigor. The same relatio nships occurred for electrically stimulated muscle. The data indicate that the basal shear-force value of lamb loin prior to aging, i.e. the basal toughness level, is 15 kgF.