Evaluation of a probe for predicting beef tenderness

A series of three experiments were conducted to evaluate the performance of the MIRINZ (Meat Industry Research Institute of New Zealand) tenderness pr obe. In the first experiment, assessments On raw samples from two different muscles (longissimus lumborum um and semimembranosus) were obtained using the tension head. Results indicated D50 values (torque at 50 degrees of rel ation) were the most highly related to both sensory (taste, olfactory, and feeling factors measured by a trained sensory panel) and consumer (hedonic ratings provided by untrained consumers) properties and were the values of choice, since all probe values were essentially measuring the same characte ristics. In the second experiment, assessments were made using both the ten sion and shear heads on raw and cooked striploin (longissimus lumborum) ste aks. Results confirmed probe values were essentially measuring the same cha racteristics, but indicated raw tension head, area 2 values (area before 50 degrees of rotation) were more highly related to both sensory and consumer properties than were D50 values. However, probe values from raw samples di d not account for a sufficient amount of variation in either sensory or con sumer properties to be useful predictors of these traits, and stepwise, lin ear regression did not improve the predictive value of raw probe values, si nce all probe values were interrelated. Probe values on cooked samples indi cated the shear head and area 3 values (area under the entire trace) were t he most related to both sensory and consumer properties and were the values of choice. Based upon the amount of variation accounted for in sensory and consumer traits, probe area 3 values using the shear head on cooked sample s provided greater predictive value for both sensory and consumer traits th an Warner-Bratzler shear values obtained from steaks cooked either fresh or after being frozen and thawed. In experiment 3, correlations with individu al, parametric character notes from the texture profiles of two different m uscles provided no clear indication as to the textural properties being ass essed by the probe. However, the MIRINZ probe appears to be a quick viable alternative to the Warner-Bratzler shear for providing an objective measure of cooked meat tenderness. (C) 2000 Elsevier Science Ltd. All rights reser ved.