The effect of high-level chlorine carcass drench on the recovery of Salmonella and enumeration of bacteria from broiler carcasses.

A study was conducted to determine the bacteriological effect of exposing processed broiler carcasses to a high (10-fold increase) concentration chlorinated drench. During each of 6 replicate trials, eviscerated prechill carcasses were obtained from a commercial processing plant and chlorine-treated carcasses were subjected to a 1-min drench in 500 mL of a 500 mg/kg chlorine solution (sodium hypochlorite). Water-drenched carcasses were treated the same way except water was used in place of chlorinated water drench. Control carcasses were not drenched. All carcasses were then subjected to a whole carcass rinse (WCR) in 450 mL of buffered peptone water, from which 50 mL of the rinsate was removed for enumeration of total aerobic bacteria (APC), Escherichia coli, and total coliforms (TC). The entire carcass was then incubated 24 h at 37°C (whole carcass enrichment, WCE) for recovery of Salmonella. Levels of bacteria recovered from WCR were lower by 0.6 log10 cfu/mL for APC, 0.8 for E. coli, and 0.9 for TC when carcasses were drenched with water compared with undrenched control levels. Similarly, the levels of bacteria recovered from WCR were further lower by 1.0 log10 cfu/mL for APC, 0.5 for E. coli, and 0.5 for TC, when carcasses were drenched with 500 mg/kg of chlorine compared with water. However, there was no significant difference (P > 0.05) in prevalence of Salmonella among the treatments (29% positive for control, 26% positive for water, 38% positive for chlorinated). These results indicate that drenching eviscerated carcasses with water or chlorinated water at 500 mg/kg significantly, but minimally, reduces the numbers of APC, E. coli, and TC bacteria recovered compared with undrenched carcasses. However, neither drenching carcasses with water or high chlorine had an effect on the prevalence of Salmonella that remain with the carcass as determined by WCE. The results of this study confirms the importance of maintaining and replenishing free chlorine for optimal antimicrobial activity, because chlorine at 500 mg/kg was rapidly used within 1 min of exposure to the carcass to <10 mg/kg.

Microbial recovery from genetically featherless broiler carcasses after forced cloacal fecal expulsion.

A study was conducted to determine external microbiology of genetically featherless broiler carcasses after forced cloacal fecal expulsion. Full-fed featherless broilers were placed into coops, transported, unloaded, shackled, stunned, suffocated, weighed, and divided into 3 treatments groups. Carcasses were transferred to a separate shackle line and passed through a machine designed to induce defecation (squeeze) and then remove external feces (wash). Treatments were obtained by turning the squeezing and washing components on or off. Treatments were as follows: S carcasses were squeezed but not washed; W carcasses were not squeezed but were washed; and SW carcasses were squeezed and washed. Concentrations of total aerobic microorganisms (AB), Escherichia coli (EC), coliforms (CF), and Campylobacter (CPY) recovered from whole carcass rinses did not vary with treatment (P > 0.05). However, counts of Salmonella (SAL) in rinses of S carcasses were 1.4 log(10) cfu/mL greater than counts of SAL found in rinses of SW carcasses (P < 0.05). The SAL prevalence was similar for S (86% positive), W (90% positive), and SW (83% positive) carcasses (P > 0.05). Populations of AB and CF recovered from wash water (water applied in the machine after fecal expulsion) for SW carcasses were significantly higher by 3.1 and 1.5 log(10) cfu/mL, respectively, than the populations of the same bacteria recovered from wash water for W carcasses (P < 0.05). Levels of EC and CPY recovered from wash water did not vary with treatment. There was no difference in CPY and SAL prevalence in water collected after washing W carcasses or SW carcasses (P > 0.05). Data from the present study show that controlled cloacal fecal expulsion followed by carcass washing immediately after slaughter can be used to minimize the numbers of carcass Salmonella and can reduce the likelihood of visible carcass fecal contamination or cross-contamination to other carcasses and processing equipment.

Proximate composition of poultry processing wastewater particulate matter from broiler slaughter plants.

An experiment was conducted to compare the proximate composition of particulate matter recovered from poultry processing wastewater (PPW) generated by broiler slaughter plants. Poultry processing wastewater is the cumulative wastewater stream generated during the processing of poultry following primary and secondary physical screening (typically to 500 mum) that removes gross offal. Composite samples of PPW from 3 broiler slaughter plants (southeast United States) were collected over 8 consecutive weeks. All 3 broiler slaughter plants process young chickens with an average live weight of 2.0 kg. At each plant, a single 72-L composite sample was collected using an automatic sampler programmed to collect 1 L of wastewater every 20 min for 24 h during one normal processing day each week. Each composite sample was thoroughly mixed, and 60 L was passed through a series of sieves (2.0 mm, 1.0 mm, 500 mum, and 53 mum). The amount of particulate solids collected on the 2.0 mm, 1.0 mm, and 500 mum sieves was insignificant. The solids recovered from the 53-mum sieve were subjected to proximate analysis to determine percent moisture, fat, protein, ash, and fiber. The average percentages of fat, protein, ash, and fiber for all samples on a dry-weight basis were 55.3, 27.1, 6.1, and 4.1, respectively. Fat made up over half of the dry-weight matter recovered, representing PPW particulate matter between 500 and 53 mum. Despite the variation in number of birds processed daily, further processing operations, and number and type of wastewater screens utilized, there were no significance differences in percentage of fat and fiber between the slaughter plants. There were significant differences in percent protein and ash between the slaughter plants.

Effects of vibratory microscreening on proximate composition and recovery of poultry processing wastewater particulate matter.

Experiments were conducted to compare the effects of tertiary microscreen gap size on the proximate composition and rate of recovery of particulate matter from poultry processing wastewater (PPW). A high-speed vibratory screen was installed within the wastewater treatment area of a southeast US broiler slaughter plant after the existing primary and secondary mechanical rotary screens. Microscreen panels with nominal gap size openings of 212, 106 and 45mum were investigated. The particulate matter samples recovered were subjected to proximate analysis to determine percent moisture, fat, protein, crude fiber and ash. The average percent wet weight moisture (%WW) content for all samples was 79.1. The average percent dry matter (%DM) fat, protein, crude fiber and ash were 63.5, 17.5, 4.8 and 1.5, respectively. The mean concentration of total solids (TS) recovered from all microscreen runs was 668mg/L, which represents a potential additional daily offal recovery rate of 12.1metric tons (MT) per 3.78 million L (1.0 million gallons US) of PPW. There was no significant difference in the performance of the three microscreen gap sizes with regard to proximate composition or mass of particulate matter recovered.

Recovery of bacteria from broiler carcasses after immersion chilling in different volumes of water, part 2.

Experiments were conducted to determine the relationship between poultry chilling water volume and carcass microbiology. In the first study, the volume of water used during immersion chilling was found to have a significant effect on the counts of bacteria recovered from broiler carcass halves; however, these volumes (2.1 and 16.8 L/kg) were extreme and did not reflect commercial levels. A second study using commercial chilling volumes was conducted with 3.3 L/kg (low) or 6.7 L/kg (high) distilled water in the chiller. Prechill broiler carcasses were removed from a commercial processing line, cut into left and right halves, and one-half of each pair was individually chilled in a bag containing low or high volume of water. Bags containing halves were submersed in a secondary chill tank containing approximately 150 L of an ice-water mix (0.6 degrees C). After 45 min, halves were removed, allowed to drip for 5 min, and rinsed with 100 mL of sterile water for 1 min. Rinses were analyzed for total aerobic bacteria, Escherichia coli, Enterobacteriaceae, and Campylobacter. When the numbers of bacteria in the half-carcass rinses (HCR) were compared, counts recovered from halves chilled in a low volume of water were the same as those recovered from the halves chilled with a high volume of water (P > 0.05). Levels found in the HCR ranged from 4.0 to 4.2 log(10) cfu/mL for aerobic bacteria, 3.3 to 3.5 log(10) cfu/mL for E. coli, 3.6 to 3.8 log(10) cfu/mL for Enterobacteriaceae, and 2.4 to 2.6 log(10) cfu/mL for Campylobacter. Data were also analyzed using a paired comparison t-test, and this analysis showed that there was no difference (P > 0.05) in the numbers of aerobic bacteria, E. coli, Enterobacteriaceae, or Campylobacter recovered from paired-halves chilled in different volumes of water. The present study shows that under the conditions outlined in this experiment, doubling the amount of water during immersion chilling (3.3 vs. 6.7 L/kg) did not improve the removal of bacteria from the surfaces of chilled carcasses.

Effect of dry air or immersion chilling on recovery of bacteria from broiler carcasses.

A study was conducted to investigate the effect of chilling method (air or immersion) on concentration and prevalence of Escherichia coli, coliforms, Campylobacter, and Salmonella recovered from broiler chicken carcasses. For each of four replications, 60 broilers were inoculated orally and intracloacally with 1 ml of a suspension containing Campylobacter at approximately 10(8) cells per ml. After 1 day, broilers were inoculated with 1 ml of a suspension containing Salmonella at approximately 10(8) cells per ml. Broilers were processed, and carcasses were cooled with dry air (3.5 m/s at -1.1 degrees C for 150 min) or by immersion chilling in ice water (0.6 degrees C for 50 min). Concentrations of E. coli, coliforms, Campylobacter, and Salmonella recovered from prechill carcasses averaged 3.5, 3.7, 3.4, and 1.4 log CFU/ml of rinse, respectively. Overall, both chilling methods significantly reduced bacterial concentrations on the carcasses, and no difference in concentrations of bacteria was observed between the two chilling methods (P < 0.05). Both chilling methods reduced E. coli and coliforms by 0.9 to 1.0 log CFU/ml. Air and immersion chilling reduced Campylobacter by 1.4 and 1.0 log CFU/ml and reduced Salmonella by 1.0 and 0.6 log CFU/ml, respectively. Chilling method had no effect on the prevalence of Campylobacter and Salmonella recovered from carcasses. These results demonstrate that air- and immersion-chilled carcasses without chemical intervention are microbiologically comparable, and a 90% reduction in concentrations of E. coli, coliforms, and Campylobacter can be obtained by chilling.

Evaluation of carcass scraping to enumerate bacteria on prechill broiler carcasses.

Experiments were conducted to evaluate a scraping method for enumerating bacteria on broiler carcasses. In experiment 1, coliforms and Escherichia coli were determined by the whole-carcass rinse (WCR) method and by scraping the skin surface and rinsing the blade (BR). In each of 2 replicate trials, 4 prechill broiler carcasses were collected from 2 different commercial processing plants. The WCR method was conducted on each carcass, then a blunt edge blade was used to scrape an area measuring approximately 80 cm(2) of the breast (front) skin and on the back of the carcass. After scraping, each blade and adhering residue was rinsed in 30 mL of 0.1% peptone. One milliliter of rinsate each from the WCR and BR was plated to determine total coliforms and E. coli. In experiment 2, 6 carcasses were collected from a processing plant in each of 2 replicate trials. Carcasses were split, with one half scraped on all skin surfaces, and the other half remaining unscraped as a control; all halves were then subjected to half-carcass rinses using 200 mL of 0.1% peptone. Coliforms and E. coli were enumerated. Results from both experiments are reported as log cfu/mL. In experiment 1, mean coliform WCR counts (5.1) were significantly higher (P < 0.05) than back BR (2.8), which were higher than front BR (2.2). Mean E. coli WCR counts (4.5) were higher than back BR (2.4), which were higher than front BR (1.6). The counts for BR adjusted for the greater surface area sampled by WCR were still lower than the WCR counts. Experiment 2 results showed no difference between control and scraped carcass halves for coliforms (4.7) or E. coli (4.6). Overall, results showed that scraping either prior to or after rinsing did not increase enumeration of coliforms or E. coli. Scraping could be a viable method to compare the numbers of bacteria on different areas of the same carcass.

Germicidal ultraviolet light to lower numbers of Listeria monocytogenes on broiler breast fillets.

Raw broiler breast fillets were subjected to germicidal ultraviolet (UV) light (dose of 1,000 microW/cm(2) for 5 min at a wavelength of 254 nm) to evaluate its potential to reduce Listeria monocytogenes numbers on raw product before shipment to a poultry further-processing plant. Boneless, skinless breast fillets were inoculated with 4 different strains of L. monocytogenes 5 min before treatment. After the UV treatment, breast fillets were stored at 4 degrees C for 24 h. Enumeration of remaining L. monocytogenes was performed using the spread plate method on modified Oxford agar. An approximate 2-log reduction in viable L. monocytogenes was observed with all 4 strains on UV-treated breast fillets as compared with the nontreated breast fillets. The UV treatment caused only slight changes in meat color (lightness, redness, and yellowness) on day of treatment or after 7 d of storage. This study suggests that UV treatment of raw breast fillets at a slaughter plant can significantly reduce L. monocytogenes without negatively affecting meat color. This process could be used to reduce the negative effect of raw poultry as a transmission vector of L. monocytogenes into a poultry further-processing plant.

Broiler carcass bacterial counts after immersion chilling using either a low or high volume of water.

A study was conducted to investigate the bacteriological impact of using different volumes of water during immersion chilling of broiler carcasses. Market-aged broilers were processed, and carcasses were cut into left and right halves along the keel bone immediately after the final bird wash. One half of each carcass pair was individually chilled at 4 degrees C in a separate bag containing either 2.1 L/kg (low) or 16.8 L/kg (high) of distilled water. Carcass halves were submersed in a secondary chill tank containing approximately 150 L of an ice-water mix (0.6 degrees C). After chilling for 45 min, carcass halves were rinsed with 100 mL of sterile water for 1 min. Rinses and chill water were analyzed for total aerobic bacteria (APC), Escherichia coli, Enterobacteriaceae, and Campylobacter. After chilling with a low volume of water, counts were 3.7, 2.5, 2.6, and 2.1 log(10) cfu/mL of rinse for APC, E. coli, Enterobacteriaceae, and Campylobacter, respectively. When a high volume of chill water was used, counts were 3.2, 1.7, 1.6, and 1.8 log(10) cfu/mL of rinse for APC, E. coli, Enterobacteriaceae, and Campylobacter, respectively. There was no difference in bacterial counts per milliliter of chill water among treatments. These results show that using additional water during immersion chilling of inoculated broilers will remove more bacteria from the carcass surfaces, but numbers of bacteria per milliliter in the chiller water will remain constant. The bacteriological impact of using more water during commercial immersion chilling may not be enough to offset economic costs.

A method for estimating the relative degree of saponification of xanthophyll sources and feedstuffs.

Saponification of xanthophyll esters in various feed sources has been shown to improve pigmentation efficiency in broiler skin and egg yolks. Three trials were conducted to evaluate a rapid liquid chromatography procedure for estimating the relative degree of xanthophyll saponification using samples of yellow corn, corn gluten meal, alfalfa, and 6 commercially available marigold meal concentrates. In each trial, samples were extracted using a modification of the 1984 Association of Official Analytical Chemists hot saponification procedure with and without the addition of KOH. A comparison of the chromatography results was used to estimate percent saponification of the original sample by dividing the nonsaponified extraction values by the saponified extraction values. A comparison of the percent saponified xanthophylls for each product (mg/kg) was: yellow corn, 101; corn gluten meal, 78; alfalfa, 97.9; and marigold concentrates A through F, 99.8, 4.6, 99.0, 95.6, 96.8, and 6.6, respectively. These results indicate that a modification of the 1984 Association of Official Analytical Chemists procedure and liquid column chromatography can be used to quickly verify saponification and can be used to estimate the relative degree of saponification of an unknown xanthophyll source.

The influence of extraction and precipitation pH on the dry matter yield of broiler dark meat.

In recent years, demand for white meat products has resulted in excess supplies and depressed prices of leg meat in the United States. One approach to increasing the utilization of dark meat is to extract the pigments and fat to make the resulting product more acceptable for the production of further-processed meat products. To date, such technologies have been inefficient (low yields) or have resulted in products of limited use. Three replicate trials were conducted to determine the effects of extraction pH and precipitation pH on the wet and dry extract yields of boneless, skinless broiler leg meat. Broiler leg meat was chopped with added water and extracted by adjusting the pH to 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, 11.5, and 12.0 while mixing. After determination of extraction yields, each extraction was adjusted to pH 3.8, 4.0, 4.2, 4.4, 4.6, 4.8, 5.0, and 5.2 to determine the effect of precipitate pH on total wet and dry yields. Dry yield increased with extraction pH and precipitation pH. However, the greatest yields, over 70%, were at extraction pH values above 10.5, which have been associated with the production of potentially harmful by-products. Combinations of extraction pH values between 9 and 10.5 and precipitation pH values above 4.4 resulted in dry yields of approximately 65%. These results indicate that pH extraction and precipitation may result in economically viable yields. Further research is needed to determine the optimal conditions of yield, composition, and functionality.

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.

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.

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.

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.

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.

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.

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.

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.

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.