High and low rigor temperature effects on sheep meat tenderness and ageing

• Published in: Meat science Vol. 60; no. 2; pp. 141 - 146
• Main Authors: Devine, Carrick E, Payne, Steven R, Peachey, Bridget M, Lowe, Timothy E, Ingram, John R, Cook, Christian J
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-02-2002; Elsevier
• Subjects: Biological and medical sciences; Food industries; Fundamental and applied biological sciences. Psychology; Meat and meat product industries; Muscle restraint; Rigor temperature ageing tenderness; Rigor temperature ageing tenderness; Muscle restraint; Ripening; Cadaveric rigidity; Temperature; Quality; Tenderness; Meat product; Environmental factor; Mutton; Carcass
• DOI: 10.1016/S0309-1740(01)00115-2
• EISSN: 1873-4138
• ISSN: 0309-1740

Immediately after electrical stimulation, the paired
m. longissimus thoracis et lumborum (LT) of 40 sheep were boned out and wrapped tightly with a polyethylene cling film. One of the paired LT's was chilled in 15°C air to reach a
rigor mortis (rigor) temperature of 18°C and the other side was placed in a water bath at 35°C and achieved
rigor at this temperature. Wrapping reduced
rigor shortening and mimicked meat left on the carcass. After
rigor, the meat was aged at 15°C for 0, 8, 26 and 72 h and then frozen. The frozen meat was cooked to 75°C in an 85°C water bath and shear force values obtained from a 1×1 cm cross-section. The shear force values of meat for 18 and 35°C
rigor were similar at zero ageing, but as ageing progressed, the 18
rigor meat aged faster and became more tender than meat that went into
rigor at 35°C (
P<0.001). The mean sarcomere length values of meat samples for 18 and 35°C
rigor at each ageing time were significantly different (
P<0.001), the samples at 35°C being shorter. When the short sarcomere length values and corresponding shear force values were removed for further data analysis, the shear force values for the 35°C
rigor were still significantly greater. Thus the toughness of 35°C meat was not a consequence of muscle shortening and appears to be due to both a faster rate of tenderisation and the meat tenderising to a greater extent at the lower temperature. The cook loss at 35°C
rigor (30.5%) was greater than that at 18°C
rigor (28.4%) (
P<0.01) and the colour Hunter
L values were higher at 35°C (
P<0.01) compared with 18°C, but there were no significant differences in
a or
b values.