Biomedical subjects

D L Fletcher

Publications and source records attributed to D L Fletcher.

At least 19 recordsLinked to original sources

PubMed2005

Recovery of salmonellae following pH adjusted pre-enrichment of broiler carcasses treated with trisodium phosphate.

Trisodium phosphate (TSP) has been reported to decrease the recovery of salmonellae from processed poultry carcasses. It has been suggested that the high pH and detergent-like properties of TSP solutions are responsible for the reduction in salmonellae recovery. This project was conducted to determine if controlling pH during salmonellae pre-enrichment alters the effect of TSP on salmonellae recovery. Carcasses were obtained from a commercial processing plant immediately after the final inside-outside carcass washer, prior to any other antimicrobial treatments, and before chilling. Carcasses were assigned to 1 of 4 treatment groups: (1) TSP and alkaline pre-enrichment, (2) TSP and neutral pre-enrichment, (3) non-TSP and alkaline pre-enrichment, 4) non-TSP and neutral pre-enrichment. Carcasses were placed into plastic bags with 500 mL of buffered peptone water (with or without pH adjustment) and shaken for 1 min. Preincubation pH of the rinsate was measured. Carcasses were incubated in the rinse at 37 degrees C for 24 h, and incidence of salmonellae was determined. The pH of the preincubation rinsate was 8.4 for the TSP alkaline pre-enrichment, 7.2 for the TSP neutral pre-enrichment, 8.6 for the non-TSP alkaline pre-enrichment, and 7.1 for the non-TSP neutral pre-enrichment. Salmonellae were detected from 40% of the TSP alkaline pre-enrichment carcasses, 44% of the TSP neutral pre-enrichment carcasses, 54% of the non-TSP alkaline pre-enrichment carcasses, and 38% of the non-TSP neutral pre-enrichment carcasses. Neither TSP treatment nor pre-enrichment pH adjustment significantly influenced carcass salmonellae detection.

Animals↗

PubMed2005

Physical and functional properties of intact and ground pale broiler breast meat.

The functional and physical properties of intact and ground meat were determined during 4 replicate trials on a total of 180 pale [lightness (L*) > 53] and normal (46 < L* < 53) boneless, skinless breast fillets collected from 2 commercial processing plants. At 24 h postmortem, L*, redness (a*), yellowness (b*), and pH were determined on each fillet. The left fillet from each breast was ground and used to determine cook loss (CL) and Allo-Kramer (AK) shear on meat patties as well as moisture uptake (MU) and CL on meat slurries before and after adjustment to the normal meat pH of 5.9. The right fillet from each breast was kept intact and used to determine expressible moisture (EM), CL, and AK shear on the intact meat. Compared with normal fillets, pale fillets exhibited significantly higher L* values, lower ultimate pH (5.67 vs. 5.94), higher AK (3.5 vs. 2.9 kg/g), higher EM, lower MU, and higher CL measured on the intact fillets, ground meat patties, and meat slurries. Adjustment of the pH of the pale meat slurries to normal meat pH (5.9) resulted in a higher MU (11.05 vs. 3.69%), indicating a partial restoration of protein functionality. These results indicate that wide differences in raw broiler breast meat color, mainly due to differences in the muscle pH, are related to important variations in the water-holding and binding capacities of the meat. The effect of low meat pH can be partially ameliorated in ground meat by pH adjustment.

Animals↗

PubMed2004

Recovery of Salmonellae from trisodium phosphate-treated commercially processed broiler carcasses after chilling and after seven-day storage.

Experiments were conducted to determine the effect of prechill trisodium phosphate (TSP) treatment on reducing salmonellae recovery from broiler carcasses immediately after chilling or following 7 d of storage. Carcasses were sampled for salmonellae using whole carcass enrichment for 24 h at 37 degrees C. In each of 7 trials, 40 carcasses were obtained from a commercial processing plant. Batches of 4 carcasses were subjected to a 5-s dip in 10% TSP (treatment) or not dipped (control). Two carcasses from each batch were sampled immediately after chilling (d 0) and 2 carcasses were sampled after 7 d of storage. For trials 1 and 2, TSP treatment and control groups were chilled in separate chill tanks for 45 min. For trials 3 through 7, carcasses were rinsed with water and individually bagged with ice and water before chilling. For trials 1 and 2, 85% (17/20) of control carcasses were salmonellae-positive on d 0 compared with 45% (9/ 20) of the TSP-treated carcasses; after 7 d, 75% (15/20) of control carcasses were positive compared with 35% (7/ 20) for the TSP-treated carcasses. For trials 3 through 7, 46% (23/50) of control carcasses were salmonellae-positive on d 0 compared with 26% (13/50) of the TSP-treated carcasses; after 7 d, 20% (10/50) of control carcasses were positive compared with 4% (2/50) of the TSP-treated carcasses. TSP treatment resulted in significantly higher pH values for rinses. Salmonella recovery was decreased by refrigerated storage and treatment with TSP before immersion chilling.

Animals↗

PubMed2004

Survey of shell egg processing plant sanitation programs: effects on non-egg-contact surfaces.

To successfully implement a hazard analysis critical control point plan, prerequisite programs are essential. Sanitation standard operating procedures are an important part of such a plan and can reduce contamination levels so that food safety and quality are not adversely affected. Noncontact surfaces in the shell egg processing plants can serve as a reservoir of cross-contamination. The objective of this study was to assess the efficacy of sanitation programs used in a variety of shell egg processing facilities (in-line, off-line, and mixed operations). Fourteen different noncontact surfaces were sampled in nine commercial facilities across the southeastern United States. Non-egg-contact surfaces were defined as those where the shell egg does not come into direct contact with the surface or with the fluid from that surface. Gauze pads soaked in sterile phosphate-buffered saline were used for sampling at the end of a processing day (POST) and again the next morning prior to operations (PRE). Aerobic plate counts (APCs) and numbers of Enterobacteriaceae were determined. No significant differences (P > 0.05) were found between POST and PRE counts for either population recovered from the 14 sampling sites. Only samples from the floor under the farm belts, nest-run loader, washers, and packer heads were reduced by 1 log CFU/ml of rinsate for APCs or Enterobacteriaceae counts. APCs of more than 10(4) CFU/ml of rinsate were recovered from many samples. Highest APCs were found on the floor under the farm belt and on shelves of the nest-run carts. High APCs were found on the wheel surface for off-line carts and on the loading dock floor. Highest Enterobacteriaceae counts were found in samples from the floor, drain, and nest-run egg cart shelves. A lack of significant difference between POST and PRE counts indicates that current sanitation programs could be improved. These data suggest that traffic patterns for the movement of eggs and materials through the plant should be reevaluated so that cross-contamination is reduced.

Animals↗

PubMed2003

Effects of stunning and decapitation on broiler activity during bleeding, blood loss, carcass, and breast meat quality.

Four experiments were conducted to determine the effects of electrical stunning and decapitation on bird activity as well as carcass and meat quality. In Experiment 1, broilers were subjected to one of four stunning and killing methods: no stun and neck cut, stun and neck cut, no stun and decapitation, and stun and decapitation. Birds were scored for severity of physical activity on a scale of 1 to 4 with 1 being no activity and 4 being severe wing flapping and muscular contractions. Carcasses were also scored for red wing tips and broken bones. In Experiments 2 to 4, all birds were stunned prior to neck cut or decapitation. Carcasses were scored as described in Experiment 1 as well as measurements of blood loss, feather removal, and breast meat pH, color, cook loss, and tenderness. Based on carcass activity in Experiment 1, decapitation following stunning was similar to a conventional stun and unilateral neck cut, except there was almost no late activity (after 60 s) observed in the decapitated birds. Decapitation following stunning did not result in any consistent carcass quality defects compared to conventional killing in the four experiments. No differences were found in 24-h lightness values, yellowness, cook yield, tenderness, and ultimate pH between conventionally killed and decapitated birds. Blood loss and breast meat redness were inconsistent. These results indicate that high frequency stunning and decapitation may be an acceptable alternative to conventional slaughter based on carcass and meat quality and by ensuring an irreversible loss of consciousness.

Abattoirs↗

PubMed2003

Effect of broiler age, feed withdrawal, and transportation on levels of coliforms, Campylobacter, Escherichia coli and Salmonella on carcasses before and after immersion chilling.

A study was conducted to determine effects of bird age at slaughter, feed withdrawal, and transportation on levels of coliforms, Campylobacter, Escherichia coli, and Salmonella on carcasses before and after immersion chilling. Broilers were processed at 42, 49, and 56 d of age after a 12-h feed withdrawal period or a 0-h feed withdrawal period (full fed). At each age, broilers were processed from two commercial farms previously identified as Campylobacter positive. One week before slaughter, broilers were gavaged with nalidixic acid-resistant Salmonella. During bleeding, cotton plugs were inserted into the cloaca of each carcass. Whole-carcass rinses (WCR) were performed before and after immersion chilling with 20 ppm sodium hypochlorite, and rinses were analyzed for coliforms, Campylobacter, E. coli and Salmonella. Log10 counts for coliforms, Campylobacter, and E. coli were (P < 0.05) affected by bird age at slaughter. Feed withdrawal (FW) affected only Campylobacter on carcasses of older broilers (56 d of age). Chilling with sodium hypochlorite resulted in log10 reductions of 1.2, 1.3, 1.4, and 0.5 for coliforms, Campylobacter, E. coli, and Salmonella, respectively. Under the conditions of this experiment, it appears that contamination on the exterior of birds entering the processing facility is critical to carcass bacterial counts. Moreover, carcass bacterial counts did not vary when microbial counts of broilers were comparable. FW may increase prechill carcass counts for E. coli and Campylobacter, but it appears to have no effect on postchill carcass counts when sodium hypochlorite is used in the chilling operation.

Aging↗

PubMed2003

Effects of replacement finisher feed and length of feed withdrawal on broiler carcass yield and bacteria recovery.

A study was conducted to determine the effects of a replacement finisher feed (RF) on carcass yield and carcass bacteria recovery. RF is a commercial formulation of a D-glucose polymer (maltodextrin) with added salts and vitamins. Commercial male broilers (41 d of age) were given either RF or control-feed (traditional starter feed) for 8 h, followed by feed withdrawal for 0, 4, 8, or 12 h before processing. During processing, whole carcass rinses (WCR) of pre-eviscerated (feathers, feet, and heads removed) and eviscerated carcasses were analyzed for recovery of bacteria. Body weight at initiation of feed withdrawal (catch weight) or at slaughter (dock weight) did not differ significantly due to type of feed. Live shrink, as a percentage of live weight, increased significantly with time off feed. Birds fed RF exhibited significantly lower live shrink than the birds fed the control feed at 8 and 12 h after feed withdrawal. This difference between types of feed, RF or control, was approximately 0.1% per hour of feed withdrawal. Type of feed or length of feed withdrawal did not affect Campylobacter, coliform, or Escherichia coli counts recovered from WCR of pre-eviscerated or eviscerated carcasses. These data demonstrate that feeding RF to broilers for 8 h before initiation of feed withdrawal may reduce live shrink without affecting carcass Campylobacter, coliforms, or E. coli recovered.

Animal Feed↗

PubMed2003

Effects of high frequency electrical stunning and decapitation on early rigor development and meat quality of broiler breast meat.

Three independent trials were conducted to determine the effects of high frequency electrical stunning followed by decapitation on broiler breast meat rigor development and meat quality. All birds were stunned and half of the birds were killed using a conventional unilateral neck cut, half were killed by decapitation, and both groups were allowed to bleed for 90 s prior to scalding and picking. New York dressed carcasses were chilled in a static ice-water bath for 90 min and held at 2 degrees C prior to deboning. Breast fillets were removed from the carcasses at 2, 4, and 24 h postmortem. From the right breast fillet, R-values and pH were determined at time of deboning. The left fillet was wrapped in plastic and held for 24 h at 2 degrees C prior to determining lightness (L*), redness (a*), yellowness (b*), cook yield, and Allo-Kramer shear. Deboning time affected raw meat pH, R-value, cook loss, and shear value but had no effect on color. The breast meat from the decapitated birds had significantly higher pH values at 2 and 24 h postmortem than the conventionally killed birds. Other than for the effect on breast meat pH, decapitation had no effect on rigor development, R-value, meat color, or meat quality as measured by cooked-meat yield and Allo-Kramer shear.

Adenine Nucleotides↗

PubMed2003

Comparison of sampling methods for the detection of Salmonella on whole broiler carcasses purchased from retail outlets.

An experiment was conducted to compare the effectiveness levels of two methods in recovering Salmonella from the same carcass. One hundred fresh whole broiler chickens were purchased from retail outlets over a 5-week period (20 carcasses per week). After carcasses had been aseptically removed from the packages and giblets had been removed, the carcasses were placed in sterile bags containing 400 ml of 1% buffered peptone water, the bags were shaken for 60 s, and a 30-ml aliquot was removed and incubated for 24 h at 37 degrees C (aliquot sample). Then, an additional 130 ml of 1% buffered peptone water was immediately added to the bag with the carcass (bringing the volume to 500 ml), the bag was reshaken, and the carcass and rinse were incubated for 24 h at 37 degrees C (whole-carcass enrichment sample). Following incubation, 0.5-ml samples for the two methods were placed into 10 ml of Rappaport-Vassiliadis broth and into 10 ml of tetrathionate (Hajna) broth and incubated at 42 degrees C for 24 h. Each broth was then streaked onto BG Sulfa agar and modified lysine iron agar and incubated for 24 h at 35 degrees C. Suspected Salmonella colonies were inoculated onto triple sugar iron and lysine iron agar slants and incubated at 35 degrees C for 24 h. Presumptive positive results were confirmed by Poly O and Poly H agglutination tests. Over the 5-week period, 13% of the aliquot samples tested positive for Salmonella, compared with 38% of the whole-carcass enrichment samples from the same carcasses. Recovery rates ranged from 0 of 20 samples to 4 of 20 samples for aliquot method and from 4 of 20 samples to 10 of 20 samples for the whole-carcass enrichment method over the 5-week period. These results indicate that when small numbers of Salmonella are expected, the sampling method has a major influence on the identification of Salmonella-positive carcasses.

Animals↗

PubMed2003

Recovery of Salmonella from retail broilers by a whole-carcass enrichment procedure.

Fresh whole broiler carcasses were purchased from grocery stores over a 20-week period. Carcasses were selected on the basis of their having intact packages and unique U.S. Department of Agriculture (USDA) plant numbers and sell-by dates, such that each bird represented a single processing plant-processing day combination. Carcasses were tested for Salmonella with a rinse aliquot obtained after whole-bird incubation in the rinse media for 24 h. On the basis of the number of unique processing plants (USDA plant numbers) and expiration dates involved, the number of birds available each week ranged from 6 to 17. Over the 20-week period, 251 independent carcasses from 14 processing plants were tested. The percentages of carcasses testing positive for Salmonella ranged from 0 (for 1 week) to >60% (for 3 weeks). For only 4 of the 20 weeks was an incidence of Salmonella-positive carcasses of <20% found. For the entire 20-week study, 85 (33.9%) of the 251 carcasses tested were found to be Salmonella positive. For those processing plants from which >10 carcasses were obtained, the percentages of carcasses testing positive for Salmonella ranged from <20 (two plants) to >40% (four plants). These results indicate that a whole-carcass enrichment may be more sensitive for the detection of Salmonella-positive carcasses than the traditional whole-carcass rinse followed by immediate testing of a subsample aliquot when small numbers of Salmonella are expected.

Animals↗

PubMed2003

Survey of shell egg processing plant sanitation programs: effects on egg contact surfaces.

Sanitation standard operating procedures (SSOPs) are an integral component of process control and are often the first step in the implementation of food safety regulations. The objective of this study was to assess and compare the efficacies of sanitation programs used in a variety of shell egg processing facilities. In-line, off-line, and mixed operations were evaluated. Sixteen direct or indirect egg contact surfaces were sampled in various shell egg processing facilities in the southeast United States. Samples were collected at the end of a processing day (POST) and again the next morning before operations began (PRE). Total aerobic plate counts (APCs) were obtained and Enterobacteriacae were enumerated. No significant differences (P > 0.05) between POST and PRE bacterial counts were found for the 16 sampling sites. In general, high APCs were found on the wall of the recirculating water tank both POST and PRE. The APCs for the rewash belt were considerably high for all plants sampled. APCs were also high for the vacuum loaders. APCs for washers and washer brushes were relatively low for most plants sampled. PRE and POST levels of plant sanitation, as determined by direct microbial plating, did not differ significantly. At this point, it is difficult to draw definitive conclusions about how rigid SSOPs should be for the shell egg processing industry.

Animals↗

PubMed2002

Variations in levels of acid phosphatase present in chicken whole leg meat.

Acid phosphatase (ACP) has been identified as a potential biomarker for endpoint temperature determination in further-processed poultry. Multiple analyses of the same sample for ACP have produced consistent results. The degree of variation in ACP levels present in different production lots has not been identified. This study was conducted utilizing a single flock of broilers. Birds were slaughtered on four separate days (replications), and whole leg, without skin, was homogenized. Proximate composition was analyzed for each replication. Water-soluble proteins were extracted from raw meat and assessed for initial ACP levels. Samples of meat were cooked to an internal temperature of 71.1 C. There were differences (P < 0.05) between replications for both moisture and fat content. When dry fat content was analyzed, no significant differences occurred between replicates. Initial ACP levels were different (P < 0.0001) between replicates (500.33 to 348.97 units of activity/kg). Levels of ACP activity after cooking were also different (P < 0.0001) between replicates (17.61 to 10.82 units of activity/kg). Percentage degradation of activity during cooking was similar (96.98 to 95.89%) between replicates. ACP levels were consistently measured within a replicate. Differences between replicates for both initial and cooked levels indicate a threshold level for determination of thermal endpoint would be difficult to establish. ACP may not be a sensitive measure to estimate the degree of doneness of meat samples in which initial ACP concentration is unknown. Identical raw sample required for such a comparison would be difficult for the processing industry to maintain.

Acid Phosphatase↗

PubMed2002

Broiler skin and meat color changes during storage.

The importance of poultry skin and meat color (both absolute and variations in color) in the market place have been well established. It has also been reported that these colors change over time. With the development of computer-assisted vision grading systems, the changes in skin and meat color during and after processing have become important, based on calibrations and assessment values based on color. Four independent experiments were conducted to determine the pattern of color change in broiler skin and meat during processing and storage. Skin color change was measured on subscald (57 C) and semiscald (50 C) breast skin surfaces and on breast and leg meat, on the carcass and following deboning and packaging. A reflectance colorimeter was used to determine lightness (L*), redness (a*), and yellowness (b*) at 20-min intervals for the first 3 h, at 30-min intervals between 3 and 8 h, hourly between 8 and 12 h, and daily up to 8 d postmortem. Results clearly show that color values for both skin and meat changed dramatically for the first 6 h postmortem, after which the changes were less pronounced. The skin from semiscalded birds showed less change than the skin from subscalded birds. These results indicate that on-line vision systems need to take into account the dramatic changes in skin and meat color during the first 6 h postmortem, after which the color changes may be less important.

Animals↗

PubMed2002

Effects of broiler breast meat thickness and background on color measurements.

Experiments were conducted to determine the influence of broiler and turkey breast meat thickness and background on breast meat color measurements. Broiler breast fillets were sliced into two 1 cm thick slices and the turkey breast fillets into three 1 cm slices. Color values for lightness (L*), redness (a*), and yellowness (b*) were measured on the same top slice singly or while placed over the corresponding broiler and turkey slices. Color was measured in triplicate while the fillets were placed on the following backgrounds: plastic-coated white paper, white nylon, aluminum foil, black plastic, and a yellow commercial packaging tray (broiler only). Sample thickness significantly affected L*, a*, and b* values of turkey and chicken. Increased breast meat thickness resulted in lower L*, a*, and b5 values. Increased turkey meat thickness from 1 to 2 cm resulted in lower a* and b* values; however, only lower L* values were observed, with sample thickness increased from 1 to 3 cm. No differences in meat color were found when increasing turkey meat sample thickness from 2 to 3 cm. Background had a significant effect on single (1 cm) broiler and turkey meat color measurements but did not influence the color readings of the thicker multiple slice samples. These results indicate that the application of machine vision or in-line color measurement systems may have to take into account breast meat thickness, and in thinner samples, background color.

Animals↗

PubMed2002

Effects of raw broiler breast meat color variation on marination and cooked meat quality.

Three replicate trials were conducted to determine the effect of raw broiler breast meat color on marinated and cooked meat quality. In each trial, 90 fillets were collected from a commercial processing plant based on lightness (L*) values of breast meat as follows: light, L* > 53; normal, 48 < L* < 51; and, dark, L* < 46. For each fillet the color, pH, and weight were determined, and the fillets were marinated in three lots of 10 fillets from each color group (20% wt:wt of 5% salt and 2.5% sodium tripolyphosphate in a vacuum tumbler). Marination uptake was determined; the samples were held for 24 h at 2 C, and color, pH, and weight again were determined. Next, the samples were cooked, and the meat was subjected to color, pH, cooked yield, shear force, and moisture analyses. Results showed that absolute color values changed with marination and cooking, but that L* and pH differences by color group were maintained through marination and cooking. There were also significant differences in marinade absorption, cooked yield, and shear value, particularly among the extremes of light and dark meats. There was no significant difference in final cooked meat moisture. As expected, there were significant negative correlations between meat lightness and pH; however, raw muscle pH was not correlated to final product moisture or shear but was positively correlated to cooked meat yield and negatively correlated to marinade absorption. These results indicate that the pH variation associated with extreme raw breast meat color variation can affect breast meat marination and cooked meat quality.

Animals↗

PubMed2002

The relationship between raw broiler breast meat color and composition.

Experiments were conducted to compare the chemical composition of broiler breast meat that was naturally lighter than normal, normal, and darker than normal. In each of three separate replicated trials (wk), fillets were obtained from three commercial processing plants. Approximately 25 fillets of each color group were selected based on International Commission on Illumination (CIE) lightness values as follows: lighter than normal (L* > 53), normal (48 < L* < 51), and darker than normal (L* < 46). The fillets from each replicate, plant, and color group were ground and mixed together, and samples for the 27 treatment groups subjected to color, pH, and chemical analyses (protein, ash, moisture, total lipids, iron, glycogen, and fatty acids profile). The whole fillets had significantly different color values for the three color groups at 0 and 24 h prior to grinding. Of the ground meat samples, there were significant treatment and plant differences in composition. There were no color treatment effects on moisture, lipid, glycogen, iron, ash, or fatty acid ratios. Meat from the light group had significantly lower protein values than the normal or dark meat and lower ash than the dark group. The light group also had significantly higher levels of C16:1 and lower levels of C18:0 and C20:4 fatty acids than the dark group. Among the three plants, there were significant effects for breast meat color and composition. Results indicated that, although plant had more effect on composition, differences by color group might indicate that extreme variation in color may be due to long-term genetic factors as well as short-term antemortem stress.

Animals↗

PubMed2002

Effect of a short-term feed outage on broiler performance, live shrink, and processing yields.

This study was conducted to investigate the effect of a 12-h feed outage at various times prior to slaughter on subsequent broiler performance, live shrink, and processing yields. Broilers were full-fed or subjected to a 12-h feed outage followed by a refeeding period of 12, 24, or 48 h. Bird live weights or feed consumption was monitored during the outage and recovery periods. Birds were subjected to a 10-h feed withdrawal period and were slaughtered using simulated commercial conditions. Carcass weights were recorded through processing for yield determinations. The 12-h feed outage affected female broilers more than male broilers. Although all birds lost weight during their respective feed outage periods, birds were able to consume enough feed upon refeeding such that no significant differences in final live weight were detected at the initiation of feed withdrawal. Female broilers processed after a 12-h refeeding period had significantly larger gall bladders (by weight) as compared to the gall bladders of birds in the other treatments. Other processing parameters were not significantly affected by treatment. A 12-h feed outage and feed replacement prior to normal preslaughter feed withdrawal does not significantly affect processing yields, provided sufficient feed is replaced for at least 12 h prior to feed withdrawal. Because total feed consumption did not change following feed outage replacement, feed must be sufficient to compensate for that not consumed during the outage.

Agriculture↗

PubMed2001

The effect of holding temperature on live shrink, processing yield, and breast meat quality of broiler chickens.

The effects of antemortem holding temperatures on live shrink, processing yields, and breast meat quality of broiler chickens were evaluated. A total of 462 broilers was reared to 45 d of age using conventional husbandry practices, removed from feed and water, and cooped 12 h prior to slaughter. During the 12-h feed withdrawal and holding time, the birds were held at 25, 29.5, or 34 C. Birds were individually weighed at cooping, prior to slaughter, and during processing to determine live shrink and processed carcass yields. The breast meat was removed at 2 or 24 h postmortem and was used to determine hot and cold boned meat pH, R-value, sarcomere length, meat color (lightness, redness, and yellowness), cooked yield, and shear value. The birds held at 34 C showed the significantly greatest live shrink, 5.7%, compared to those held at 29.5 or 25 C with 3.9 and 3.2% shrink, respectively. Birds held at 34 C exhibited significantly lower processed carcass yields based on initial catch weight, but when calculated using postshrink weights, there were no significant differences between treatment groups. For breast meat harvested at 2 h postmortem, the birds held at 25 C had higher R-values, redness, and yellowness values and lower cooked meat yield and shear values. For breast meat harvested at 24 h postmortem, the birds held at 25 C had higher pH, R-values, and redness. These results support earlier reports that holding conditions may dramatically effect live bird shrink and apparent yields (based on calculation denominator) but have relatively little effect on subsequent breast meat quality, regardless of postmortem deboning time.

Animals↗