Influence of beef carcass stretching and chilling rate on tenderness of m.longissimus dorsi

Sides of 31 non-stimulated carcasses of young bulls were subjected to the m uscle stretching methods Tenderstretch (TS) by pelvic bone suspension or Te ndercut (TC) with two skeletal cuts or served as controls by traditional Ac hilles tendon suspension. The sides were chilled at fast and medium rates, resulting in temperatures of 4-5 and 9 degreesC in the in. longissimus dors i (LD) at 10 h post mortem. The LDs were examined for sarcomere length, War ner-Bratzler peak shear force and sensory properties after 8 days of ageing at 4 degreesC. At the fast chilling rate, TS and TC increased sarcomere le ngths, reduced shear force and improved sensory tenderness of the LDs compa red to the controls (P < 0.05). At the medium chilling rate, sarcomere leng ths increased (P < 0.05), but no significant differences were found in shea r force or sensory tenderness (P > 0.05) of the muscles due to stretching. However, the medium chilling rate was efficient in producing tender LDs wit hout applying muscle stretching methods. TS and TC are feasible alternative s for improving overall tenderness and reducing variation in tenderness of beef LD at cold shortening chilling conditions. (C) 2000 Elsevier Science L td. All rights reserved.