ABSTRACT: The objective of this study was to evaluate
processing methods for frozen beef subprimals; the
effects of freezing and thawing rates on tenderness,
sensory properties, and retail display were evaluated.
There were 6 treatments: fresh, never frozen 14 d wet
aged (14D); fresh, never frozen 21 d wet aged (21D);
blast frozen–fast thawed (BF); blast frozen–slow
thawed (BS); conventionally frozen–fast thawed (CF);
and conventionally frozen–slow thawed (CS). All frozen
beef subprimals were aged for 14 d before freezing.
Three beef subprimal cuts, rib eye roll (n = 90), strip loin
(n = 90), and top sirloin butt (n = 90), were used with 3
replications of 5 samples per treatment per week (total
of 9 wk, n = 270). Blast freezing occurred by placing
spacers between the boxes of meat on pallets at −28°C
with high air velocity for 3 to 5 d. Conventional freezing
occurred with boxes of meat stacked on pallets and
placed in a −28°C freezer with minimal air movement
for at least 10 d. Fast thawing of subprimals (to an internal
temperature of −1°C to 1°C) occurred by immersion
in a circulating water bath (<12°C) for 21 h, and slow
thawing of subprimals occurred over a 2-wk period by
placing individual subprimals on tables at 0°C. Steaks
(2.5 cm thick) were cut from the longissimus thoracis
(LT), longissimus lumborum (LL), and gluteus medius
(GM) for Warner-Bratzler shear force (WBS), trained
sensory evaluation, and retail display. For LL and GM
beef steaks, frozen treatments were equal or lower in
WBS values to 14D and 21D beef steaks. No differences
were detected in WBS among the treatments applied
to GM beef steaks (P = 0.08). There were no differences
in sensory tenderness among the LL, LT, and GM (P >
0.05). All LL and LT beef steaks had approximately
4 d to 40% discoloration, and all GM steaks had over
3 d to 40% discoloration. Steaks from the LL and LT
began to discolor at about 3 d, and the GM began to
discolor after 1 d. For all beef subprimals, purge loss
during storage and thawing was signifi cantly greater
for the slow-thawed subprimals (P < 0.01), and all fastthawed
subprimals were equal or superior to 14D and
21D (P < 0.01) in storage and thawing purge. During
retail display, the greatest purge loss occurred in fastthawed
treatments (P < 0.01). Overall, freezing rate did
not affect purge loss, and neither freezing nor thawing
rates had signifi cant meaningful effects on WBS, and
sensory properties were comparable with fresh, neverfrozen
subprimals.
การแปล กรุณารอสักครู่..
