Relationship between objective measurements and taste panel assessment of beef quality

Abstract

The relationship between objective measurements (shear force, compression, drip loss, cooking loss) and sensory evaluation of tenderness and juiciness of samples of M. longissimus thoracis et lumborum was examined using data from 2 experiments which imposed different electrical stimulation and aging treatments post mortem, with resultant differences in sensory and objective measures of tenderness. The relationships were tested first in separate models for each objective measurement, and then in multiple regressions containing all measurements. These models were then repeated with the inclusion of stimulation and aging treatments and their interactions with each objective measurement. Shear force by itself was a useful predictor of sensory tenderness score, with which it had a quadratic relationship. Compression and cooking loss, when used by themselves, accounted for substantially less variation in sensory tenderness scores than did shear force, with larger residual standard deviations (r.s.d.). Drip loss had no significant relationship with sensory tenderness scores. Inclusion of post-slaughter treatment in the analyses increased the amount of variation in sensory tenderness scores accounted for by only a small amount in the case of shear force, with a substantial increase in the case of compression and cooking loss. Use of all objective measurements in the 1 model had a similar predictive ability (r² , r.s.d.) as the use of shear force plus treatment variables. Aging affected the sensory tenderness scores given by taste panellists, in that they gave 14-day aged meat higher tenderness scores (more tender) than they gave 1-day aged meat with the same shear force, compression or cooking loss values. Electrical stimulation did not affect the relationship between sensory tenderness scores and shear force, but did affect that between sensory scores and compression. The effect was similar to that seen for aged meat, with stimulated meat being scored as more tender by a taste panel than non-stimulated meat, at the same compression values. Post-slaughter treatment did not affect the slope of these relationships. When all objective measurements were analysed together, aging period affected the relationship between tenderness scores and objective measures, with tenderness scores being lower in 1-day aged samples than 14-day aged samples at the same combination of objective measures. There was only a poor relationship between shear force, compression, drip loss, cooking loss and sensory juiciness scores.