|Institution:||Texas A&M University|
|Full text PDF:||http://hdl.handle.net/1969.1/5873|
Biomechanical compression studies at different temperatures were conducted to correlate the biomechanical response of raw bovine Longissimus dorsi muscles varying in USDA Quality Grade with overall sensory tenderness scores. Phase 1 assessed the biomechanical properties of raw 2.54 cm3 samples obtained with a Texture Analyzer fitted with a 10 cm diameter platen which applied a constant strain of 3% for four minutes. Muscle specimens were arranged with fibers in parallel and perpendicular orientations to the applied force and tested at 0, 2, 4, 6, 8 and 10????C. Initial stiffness, final stiffness and energy dissipated of raw steak cubes with fiber orientation in parallel and perpendicular fiber orientations were calculated using the models and technique of Spadaro (1996) and correlated to overall sensory tenderness scores for each compression temperature. All compression values had higher correlation coefficients with overall sensory tenderness than did Warner-Bratzler Shear Force (WBSF). Of the prediction equations developed, it was concluded that samples compressed perpendicularly at 2????C were better predictors of overall sensory tenderness (R2 = 0.77) than WBSF (R2 = 0.11). Phase 2 assessed the biomechanical properties of raw steaks (2.54 cm thick) using a 2 mm diameter stainless steel probe in lieu of the platen and compressing samples 0.635 cm for 0.25 sec at -6.6, 4.4 or 10????C. Initial stiffness (ISTFPR), final stiffness (FSTFPR) and energy dissipated (EDPR) of raw intact steaks were calculated using a modification of the models and technique of Spadaro (1996) and correlated to overall sensory tenderness scores for each compression temperature. ISTFPR, FSTPF and EDPR values regressed against overall sensory tenderness produced higher R-square values (R2 = 0.71 at 4.4????C and R2 = 0.70 at 10????C) than prediction equations using WBSF (R2 = 0.65). The significance of this study was that sensory tenderness could be predicted rapidly and more accurately on intact raw loin samples using a nondestructive probe measurement than could be predicted with WBSF. This innovative technique could potentially be used as a selection tool to ensure beef tenderness, be integrated into an on-line USDA Quality Grading system and be utilized as a powerful non-destructive research technique.