The relationships between sensory traits (tenderness, juiciness, flavour and overall liking) and objective measures, such as shear force, intramuscular fat, cooking loss, pH and animal age, were derived for M. longissimus thoracis et lumborum (LL) from 471 lamb and sheep carcasses. Tenderness could be predicted with the most accuracy (R2 = 0.24) and flavour with the highest precision (r.s.d. = 7.5 units) when using the objective measures, which may be in part due to the small variation in the range of shear force values of the samples (all carcasses electrically stimulated and meat aged for 5 days) and the use of consumer panels for the assessment of sensory traits. The ultimate pH of the LL, the rate of decline in pH in the LL or the predicted temperature at pH 6.0 were not significant predictors of the sensory traits when tested on a subsample of the carcasses. The model coefficients indicated that all sensory traits (tenderness, flavour, juiciness and overall liking) declined as shear force and age increased, and as intramuscular fat percentage decreased. This translated into a decline of 16 points on average for tenderness and 13 points for overall liking when LL samples from 68.5-month-old sheep were compared with those from unweaned lambs, when adjusted to the same level of intramuscular fat and shear force. Predictions of the sensory traits at varying levels of shear force were made and show that at 49 Newtons (N), the overall liking score would be 51 and the tenderness score 48. Derived relationships between objective meat quality measures and sensory traits suggest that to achieve a failure rate of no more than 10% for loin meat when eaten, it must have a shear force of about 27 N or less.

The magnetoresistance of semimetallic InAs͞GaSb superlattices has been measured in parallel magnetic fields. The temperature dependence reveals for the first time the existence of a minigap at the anticrossing points between the electron and hole dispersion relations. At high magnetic fields, samples which are close to intrinsic show surprisingly large decreases in resistance of up to 70%. The magnetoresistance also depends on crystal orientation. We present a theoretical model which explains the experimental observations and estimates the minigap to be of order 7 meV.

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