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by
D.P. Smith |
Total Records (
7 ) for
D.P. Smith |
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D.P. Smith
and
J.K. Northcutt
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The bloody, undercooked appearance of fully cooked chicken causes complaints and product rejection by consumers. This defect has been described as a persistent problem with bone-in chicken. Many studies have addressed pink meat or bone darkening, but none have studied the red discoloration problem. Therefore, constituents found in the broiler carcass (breast meat, blood and bone marrow) were combined in an external system to determine the effect of blood and marrow on inducing red discoloration. Three replicate trials were conducted where broiler breast meat was combined with: nothing (control); blood; bone marrow; or, both. An identical set of samples was prepared with added marinade (water, salt and phosphate). Duplicates of each treatment were prepared, placed in glass tubes and cooked. CIE L* (lightness) and a* (redness) values were determined on raw preparations and on cooked meat. Blood, marrow and the combination of both produced significantly (P < 0.05) darker and redder raw and cooked breast meat. Blood contributed more to the darkness of raw meat, while marrow contributed more to the darkness of cooked meat and to the redness of both raw and cooked meat. The blood-marrow combination produced darker raw and cooked meat than either ingredient alone, but the combination did not produce redder meat than marrow alone. Marination resulted in darkened raw breast meat, but had little effect on meat darkness or redness when blood, marrow, or both were added. Marrow was determined to be the most important component for inducing red discoloration of breast meat. |
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D.P. Smith
and
J.K. Northcutt
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Consumers and customers typically reject fully-cooked chicken that has a red/bloody appearance even if the product is otherwise safe and wholesome. Unfortunately, chicken parts and whole bird products may exhibit this problem on a consistent basis. This study was conducted to intentionally induce a red/bloody appearance in fully-cooked chicken to create a model for studying methods to control this defect. Five trials were conducted using bony marrow (harvested from the interior of epiphyseal end caps) from either fresh femurs (three trials) or frozen femurs (two trials) that were prepared and placed in contact with chopped broiler breast meat. Meat and marrow were packed into glass tubes and heated to one of three endpoint temperatures (74, 79, or 85oC). Five replicate tubes were prepared for each endpoint temperature in each trial (n = 75). After cooking and immediate cooling, CIE lightness (L*) and redness (a*) was determined for both the surface of the meat adjacent to the bony marrow and the surface of the marrow. The surfaces of the meat from samples prepared with fresh marrow were darker (lower L* values) and redder (higher a* values) than control meat surface samples. Each higher endpoint cook temperature resulted in a significantly (P < 0.05) lighter and less red sample. The meat exposed to frozen marrow was affected by temperature to a lesser extent as lightness increased only at 79oC and redness values did not significantly decrease from 79 to 85oC. Lightness of the marrow surface was unaffected by freezing or endpoint cook temperature. Marrow surface redness was decreased as cook temperature increased and freezing appeared to decrease the redness of samples cooked at either 74 or 79oC. Bony marrow was effective at inducing a red, bloody discoloration in breast meat samples. Higher cook temperatures and freezing femurs (before harvesting marrow) improved meat lightness and redness values, although not to control values. |
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L.L. Young
,
D.P. Smith
,
J.A. Cason
and
J.M. Walker
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The objective of this study was to evaluate combined effects of whole carcass electrical stimulation and polyphosphates on moisture absorption and retention by marinated non-aged boneless chicken breast fillets. Breast fillets were harvested from electrically stimulated and non-stimulated carcasses immediately after chilling. Half were immediately marinated in saline solution and half in a similar solution containing sodium tripolyphosphate. Muscle pH before and after marination, marinade absorption and cooking loss were recorded. Electrical stimulation immediately depressed muscle pH, but polyphosphate marination mitigated that trend somewhat. Electrical stimulation improved marinade absorption (10.6±0.3% verses 8.8±0.3%) but did not affect cooking loss. Polyphosphates did not affect marinade absorption, but significantly reduced cooking losses (17.3±0.4% verses 14.1±0.4%). No marinade by electrical treatment interactions affecting moisture absorption or retention by the fillets were detected. |
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L.L. Young
,
D.P. Smith
,
J.A. Cason
and
J.M. Walker
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Early harvested broiler breast fillets from electrically stimulated and non-stimulated carcasses were marinated in either saline or saline containing sodium tripolyphosphate to determine whether the stimulation and phosphate interact in such a way as to affect texture or color of non-aged breast fillets. Stimulated carcasses produced fillets with lower pre-marination pH (6.1 ±0.1 verses 6.5 ±0.1) and shear values (6.4 ±0.3 kg verses 15.5 ±0.3 kg) than unstimulated carcasses. Polyphosphate increased shear values of fillets from unstimulated by almost 1 kg, but not of those from stimulated carcasses. No other stimulation by polyphosphate interactions that affect texture or color of the fillets were detected. |
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L.L. Young
,
J.A. Cason
,
D.P. Smith
,
C.E. Lyon
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J.A. Dickens
and
J.M. Walker
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This study was conducted to determine effects of carcass electrical stimulation and alternative carcass chilling methods on texture and yield of early-harvested boneless broiler-breast fillets. New York dressed broiler carcasses were electrically stimulated for 90 s immediately after defeathering. Control carcasses were held similarly for 90 s but not stimulated. After evisceration, half the stimulated and half the control carcasses were chilled for 3 h in ice-water (extended immersion chilled). Remaining carcasses were chilled in ice-water for 1 h and then stored for an additional 2 h (conventionally chilled). Breast fillets (Pectoralis major muscles) were manually harvested immediately after chilling (3.5 h post-mortem). After weighing and overnight storage, all muscles were cooked and evaluated for shear values and cooked yields.
Fillets from stimulated carcasses required significantly less force to shear and exhibited greater cooked yields than those from non-stimulated carcasses. Fillets from conventionally chilled carcasses exhibited greater yield than those from extended chilled carcasses, but chilling method did not affect shear values. |
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W.R. Windham
,
D.P. Smith
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M.E. Berrang
,
K.C. Lawrence
and
P.W. Feldner
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Broiler processing may result
in fecal contamination of the surfaces of carcasses. Fecal contaminants
on broiler carcasses are prohibited due to the potential presence of
bacterial pathogens. The objective of this study was to determine the
effectiveness of the hyperspectral imaging system to detect cecal contamination
of known mass. On each of three replicate sample days, twenty-four eviscerated,
pre-chilled broiler carcasses were collected from a commercial processing
plant. Broiler carcasses were cut longitudinally into contra-lateral
halves using a sanitized saw. Cecal contents from the same flock were
also collected and used to contaminate carcass. Contents of multiple
cecal were combined, homogenized and used to contaminate carcass. Carcass
halves were imaged uncontaminated and cecal contents (10, 50, or 100
mg) were applied to the carcass half, and then re-imaged. Cecal detection
results varied due to contaminate detection threshold. The imaging system
correctly identified 100% cecal mass applied at a threshold of 1.00
and 1.05 but also incorrectly identified 252 and 65 carcass features,
respectively that were not contaminates (false positives). False negative
were only associated with the 10mg mass and a detection threshold of
1.10. The percentage of true positive cecal pixels (ie. ground truth)
detected also varied due to the detection threshold. Averaged across
cecal mass, the percentage of the cecal ground truth detected was 74,
55 and 35% for the 1.00, 1.05 and 1.10 threshold, respectively. The
percentage of contaminated pixels not detected were a spectral mixture
of cecal and uncontaminated skin. Detection of mixed pixels in small
contaminants (ie. 10mg and less) or an aggregate of several single-pixels
is essential for contaminant identification. Detection of mixed pixels
in large contaminants is not significant to overall contaminant identification. |
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D.P. Smith
,
J.K. Northcutt
and
M.T. Musgrove
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Processors are washing carcasses
with one or more inside-outside bird washers (IOBW) to comply with the
zero tolerance for visible feces regulation mandated by the USDA Food
Safety Inspection Service. A study was conducted to determine the effect
of an IOBW on total aerobic bacteria, E. coli, Campylobacter,
and Salmonella recovered from uncontaminated (control), contaminated,
and possibly cross contaminated broiler carcasses at two different IOBW
water pressure settings. In each of three trials, 12 commercially processed
carcasses, divided into two groups each containing two control carcasses,
two carcasses contaminated with 0.1g cecal contents (inoculated with
Campylobacter and Salmonella), and two carcasses uncontaminated
and placed adjacent to contaminated birds during washing (to determine
cross contamination) were prepared (n=36). Whole carcass rinses were
conducted on carcasses before contamination and washing, then again
after washing. Carcasses were washed with an in-line commercial IOBW
set at 140 birds per minute for a 5 sec dwell time and either 276 or
552 kPa (40 or 80 PSI) water pressure. Counts of total bacteria, E.
coli, Campylobacter, or Salmonella were not significantly
affected (P< 0.05) by contamination with feces, by cross-contamination,
or by IOBW pressure. The overall effect of washing was a slight but
significant reduction in total aerobic bacteria (4.9 to 4.8) and E.
coli (3.2 to 3.0) log cfu/ml rinsate. The IOBW decreased the incidence
of Campylobacter from 22/36 positive carcasses (14 positive incoming
carcasses plus 8 inoculated carcasses) to 1/36 positives, while Salmonella
incidence decreased from 12/36 contaminated (inoculated) carcasses to
3/36 positive carcasses after washing. The IOBW removed carcass contamination
to levels equivalent with uncontaminated controls without cross contaminating
other carcasses. The incidence of Campylobacter was decreased,
as was Salmonella to a lesser extent. Small reductions of bacterial
numbers were noted for total bacteria and E. coli. |
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