Twenty-four USDA Select strip loins
(IMPS 180) were aged (32°F) until 14 days
postmortem and fabricated into longissimus
muscle (strip loin) steaks (1-in. thick). Then,
steaks were either cooked or stored at −20°F
for an additional 17 days before they were
thawed and cooked. Cores and sensory panel
samples were removed from the medial,
center, and lateral sections of each steak and
locational identify maintained. In addition, a
random composite of cubes from an entire
steak was used for a sensory panel
evaluation. Previously frozen steaks had
lower Warner-Bratzler shear force (WBSF)
values, less cooking loss, and a shorter
cooking time than fresh (non-frozen) steaks;
however, no difference was found for
combined thawing and cooking loss. Cores
from the medial section of steaks had lower
WBSF values than cores from the center
section. A sensory panel found that the medial
section was more tender than the lateral section
and had less detectable connective tissue than the
center or lateral sections or samples taken at random.
The center and random treatments were
juicer than the lateral section. Highest
correlations between sensory panel tenderness
and WBSF were obtained when the medial and
lateral sections were averaged (r=−0.74, r=−0.69)
and when all three sections were averaged
(r=−0.70, r=−0.69) for fresh and frozen WBSF
steaks, respectively. Freezing lowered WBSF
values and the medial section of the steak
was the most tender. An awareness of these
results and potential procedural artifacts
must be considered when handling and
sampling steaks, and interpreting results.
