- Email: [email protected]
An Evaluation of On-Line “Reprocessing” on Visual Contamination and Microbiological Quality of Broilers
81997 Applied Poultry Science, Inc
A N EVALUATION OF ON-LINE"REPROCESSING" ON VISUAL CONTAMINATION AND MICROBIOLOGICAL QUALITY OF BROILERS
Primary Audience: Poultrv Processors. Researchers
I
reprocessing procedures include washing, DESCRIPTION OF PROBLEM vacuuming. and trimming, either individually At present, the USDA allows for the offline reprocessing of visually contaminated carcasses. These reprocessing procedures include the removal ofthe bird from the processing line, reprocessing in an approved off-line area for removal of contamination, then chlorination, and finally reinspection. Approved 1
To whom correspondence should be addressed
I .
or in combination [I]. Several studies have shown that off-line reprocessed carcasses are microbiologically indistinguishable from inspection-passed carcasses [2,3,4,5]. Waldroupet al. concluded from a large multi-state study that carcasses subjected to USDA-approved reprocessing
Downloaded from http://japr.oxfordjournals.org/ at umontanalawschool on April 8, 2015
D.L. FLETCHER' and E. W CRAIG Depamnent of Poultry Science, The University of Georgia, Athens, GA 30602 Phone: (706) 542-2476 F M : (706) 542-2475 J. W ARNOLD USDA-ART, Richard B. Russell Agricultural Research Center, Athens, GA 30613
Research Report 437
FLETCHER et al.
All bird carcasses used in this study were removed from the line as the carcasses exited the inside/outside bird washer. Samples were collected only on the night shift of a Monday, Tuesday, or Wednesday over approximately a 4-wk period until 10 replicate trials were completed. Only fully dressed, intact, and otherwise defect-free carcasses were used (to prevent secondary identification during subsequent “blind“ scoring). Water chlorine levels in the inside/outside bird washer were determined at the beginning and end of each trial. In each trial (day), carcasses were collected according to one of three experimental treatment groups of 15 carcasses each: a pretest control group (Control-1), a test group, and a post-test control group (Control-2). The Control-1 group consisted of 15 inspectionpassed carcasses removed from the line at random following the inside/outside bird washer. The test group consisted of 15 carcasses identified by the USDA line inspectors as being visually contaminated and subject to off-line reprocessing. These 15 carcasses were left on the lime, the shackle marked, and the carcasses allowed to proceed with the inspection-passed carcasses until removal from the line following the inside/outsidebird washer. The post-test Control-2 group was then collected as described for the Control-1 group. This second control group was collected to ensure against line or flock changes over time, such as bacteria accumulation along the line or sudden pockets of heavily contaminated carcasses, which would result in apparent treatment effects. As each group of 15 carcasses was being removed from the line, 5 were randomly selected, placed in pre-coded bags, double bagged, and packed on ice for transport to the lab for microbiological sampling and analyses the next day. The remaining 10 carcasses from each group were also placed in pre-coded bags but were hung by one leg on a reprocessing rack. After the three groups were collected, the carcasses were randomized across groups, the bags removed, and the carcasses subjected to individual carcass reinspection by the plant USDA Inspector-in-Charge (IIC) at the reprocessinginspection area (under adequate inspection lighting). Care was taken to prevent surface drying and cross contamination (by bagging) and temperature factors from influ-
MATERIALS AND METHODS The study was conducted in a commercial processing plant equipped with the Simmons’ Advanced System for Evisceration (SASE) [6] installed on one line running at 70 birddmin. This system includes a gizzard harvester (Model SGH-ZOO), cropper/neck breaker (Model SCR-2300), lung remover (Model SLR-8OOO), and a chlorinated inside/outside bird washer (Model SBW-3100) positioned just prior to the plant pre-chill check station.
Downloaded from http://japr.oxfordjournals.org/ at umontanalawschool on April 8, 2015
are as safe microbiologically as those that pass inspection [4]. A study conducted in Canada reported similar results [5]. Currently, many processing plants average between 2 to 5% reprocessing (20,OOO to 50,000 birddwk). A large proportion of the carcasses sent to reprocessing are contaminated with ingesta usually removed during reprocessing. It has been proposed that improvements in equipment design and on-line washing could greatly reduce the number of carcasses sent to off-line reprocessing. Under such a scheme, visually contaminated carcasses would not be removed from the line at the current inspection station but would be allowed to proceed through evisceration and a chlorinated inside/outside bird washer prior to examination for visual contamination at a checkpoint prior to entering the chiller. Carcasses still showingvisual contamination at the pre-chill checkpoint would then be removed for manual off-line reprocessing. On-line processing would have the potential advantages of reducing the number of carcasses removed from the line for minimal reprocessing as well as allowing more carcasses to enter the chiller in less time. Advances in equipment design have resulted in processing systems which reduce contamination during evisceration and which are better able to remove visual contamination through more thorough inside and outside bud washing. The purpose of this project was to evaluate one of these new systems in a commercial processing plant environment to determine if the need for off-line reprocessing could be reduced or eliminated. Carcasses showing visual contamination would be subjected to on-line processing and chlorination and then compared to inspection-passed carcasses both for the presence of visible contamination and for microbiological examination.
438
Control-2), and 10 replicate trials (days). For the visual scoring, there were 10 carcasses per treatment and trial (total n = 300). For the microbiological data, there were 5 carcasses per treatment and trial (total n = 150). The microbiological data was corrected to an equivalent of 100 mL rinse recovery and converted to loglo units for statistical analyses. Data were analyzed using the analyses of variance option of the GLM procedure of the Statistical Analyses System (SAS) computer program for the main effects of treatment and trial [12,13].
RESULTS AND DISCUSSION Under average conditions, it took approximately 20 min to collect each of the two control samples, and about 30 min to collect the test samples. The limiting factor on the control groups was the time necessary to remove and handle each bird. The Test group took longer to sample since the inspection-failed carcasses were identified at only one of the two inspection stations. Also, as the inspection-failed carcasses were removed from the line, they were examined and confirmed to be otherwise intact and free of defects. Since normal reprocessing rates are less than 3%, it would take a minimum of approximately 21 min to obtain the required 15 carcasses. Therefore, the average sampling time for all 45 carcasses ranged from about 70 to 120 min. During this time, approximately 5000 to 8OOO carcasses will have passed down the line, meaning that the 45-bird sample represented less than 1% of the line throughput. This would also indicate that the impact of the test carcasses on the subsequent data would be negligible compared to other variables in bird, flock, and normal processing. Chlorine levels were targeted to range between 20 and 30 pprn in the inside/outside bird washer and was monitored before and after sampling. The results of the chlorine analyses appear in Table 1.Chlorine averaged 24.8 ppm at the beginning and 27.1 pprn after sampling. Chlorine never went below 20 ppm, but values did exceed 30 ppm on 3 of the sample days. The results for the reinspection scores by trial and percent summary for the combined trials appear in Table 2. In the two control groups, a total of 5 and 7% of the originally inspection-passed carcasses failed reinspec-
Downloaded from http://japr.oxfordjournals.org/ at umontanalawschool on April 8, 2015
encing the reinspection. The reinspection was conducted such that the IIC was "blind relative to treatment identification. Each carcass was individually scored for the presence or absence of visible contamination appearing as digestive tract contents, specks, or tiny smears of ingesta or feces. If carcasses were identified as being visibly contaminated, the IIC made a subjective score based on the following criteria: Score 1 - visible contamination was "lod' if only one identitiable speck or smear of ingesta or feces of any size measured 1/16 in. or less in its greatest dimension; such contamination would be visible only under close examination not possible under normal line speeds and inspection conditions; Score 2 - visual contamination was "high" or obvious if more than one identifiable speck or smear of ingesta or feces were noticed and/or if one or more speck or smear were more than 1/16 in. at its greatest dimension; such contamination would likely be detected under normal line inspection speeds and conditions. The subjective visual score did not imply any quantitative assessment of contamination,but rather the ease of visual detection. Time for off-line reinspection was not limited and normally ranged from 5 to 11min. The 15 carcasses identified for microbiological evaluation were transported on ice and held under refrigeration for approximately 10 to 12 hr prior to evaluation. Carcasses were individually weighed; carcasses were sampled by rinsing in the individual polyethylene bags with 100 mL of sterile phosphate-buffered saline and shaken for 1min according to the procedure of Dickens et al. [7l.The carcasses were removed, and the rinse volume left in the bag was measured. For total aerobes, 1mL of the rinse was plated onto aerobic plate count agar by 10-fold dilution series and incubated at 37°C for 48 hr. Total coliforms were enumerated using the 3-tube MPN with Brilliant Green Bile 2% media [a]. The presence of Salmonella was determined using the procedure of Cox et al. [9, 101. Cmpylobacter species were determined using an aliquot of the carcass rinse fluid which was centrifuged (SO00 rpm, 10 min, 4°C) and resuspended in PBS. A 100-pL sample was then plated onto Cefex media and incubated at 42°C for 24 to 32 hr [ll]. The experimental design consisted of three treatments (Control-1, Test group, and
ON-LINE, "REPROCESSING"
Research Report 439
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BEGINNING
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END
(3 @pm)
I
1
22
24
2
23
24
3
24
21
4
26
30
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24
175
6
295
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9 10
Mean
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23 2
I I I
6 225 275
24.8
365
I 1 I I I
29 27 31
31 27.1
I I I I I
tion. Of the reinspection-failed carcasses, only one of the five in Control-1 was considered obvious or "high" (Score 2), while five of the seven reinspection-failed carcasses in Control-2 were considered obvious or "high" (Score 2). These results indicate that between 5 and 7% of the carcasses originally inspection-passed on the line were either missed during inspection or picked up some
TABLE 2. Summary of inspection scores (failure occurrence/lO carcasses) by trial and percent summary of the combined trials for the Control-1, Test, and Control9 groups
*Score 1: Visible contamination was "low" if only one identifiable speck or smear of ingesta or feces of any sizc measured 1/16 in. or less in its greatest dimension; such contamination would be visible only under close examinatior not possible under normal line speeds and inspection conditions. BScore 2: Visual contamination was "high"or obvious if more than one identifiable speck or smear of ingesta or feces were noticed and/or if one or more speck or smear were more than 1/16 in. at its greatest dimension; such rnntiminntinn wniild likplv he detected under normal line insuection soeeds and conditions.
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I I I
1
7
contamination during viscera removal, washing, or handling prior to reinspection. Half of the reinspection-failed carcasses in the two control groups were at a level which should be obvious under normal line inspection conditions (Score 2) as opposed to off-line reinspection with no time limit. For the inspection-failed and on-line reprocessed carcasses (Test group), 33 failed reinspection, and of those 33 visually contaminated carcasses, 19 were considered obvious or ''high'' (Score 2). These results indicate that 67% of the carcasses could have been processed on-line. A comparison of the Score 1 and Score 2 results indicate that 81% of the carcasses originally inspection-failed would have been cleaned sufficiently to have passed later on-line inspection at the pre-chill check station. By comparing the visual contamination results of the two control groups with the Test group, it appears that on-lineprocessing could reduce the number of carcasses requiring offl i e reprocessing by approximately 73 to 84%. This estimate is based on the average of a 6% control failure with a 67% clean-up rate for totalvisual contamination (6 + 67 = 73%) or a 3% control failure and 81% clean-up rate based on practical ability to discern visual con-
ON-LINE "REPROCESSING"
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Control-1 group, followed by 74% in the Control-2 group, and 72% in the Test group. These results clearly demonstrate that there were no negative effects in regards to these two organisms regarding on-lineprocessing as opposed to inspection-passed carcasses. It also appears that visible contaminationhas no significant relationship to either total bacterial counts or to the presence of either Salmonella or Campylobacter. A summary of the IIC comments and observations for each trial appears in Table 6. As would be expected,variations in the visible contaminationload and plant operationvaried across trials. The only trial in which operational problems occurred was Trial 8 where maladjusted evisceration equipment and high contamination loads were combined. Since treatment was not significant for any of the parameters tested, nor were there any trial x treatment interactions,the data were analyzed across trials. However, it should be noted that the significant effect for coliforms existed in only 3 of the 10 trials, with exactly the same pattern (Le., Control-1 was si&icantly lower than either the Test group or Control-2,which were not significantly different from each other in Trials 3, 6, and 7). There were no significant differencesin any of the other seven trials. These results indicate that although the on-line processing did not remove all of the
TREATMENT
n
TRIAL (Day)
TREATMENT X TRIAL
P Carcass weight (g)
149
0.3363
0.0278
0.0705
APC
149
0.7665
0.0001
0.2560
Coliforms
149
0.0043
0.0001
0.1122
CamDvlobacter SPP.
113
0.6587
0.0001
0.0978
CONTROL-1
TREATMENT
CONTROL3
APC
5.39
Log10 5.41
5.43
Coliforms
4.19b
4.52a
4.48a
2.90
3.23
3.15
spp.
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tamination at commercial processing plant line speeds (3 + 81 = 84%). The results of the analyses of variance for carcass weight, aerobic plate count (APC), coliform count, and Campylobacter counts appear in Table 3. Treatment was not significant for carcass weight, APC, or Campylobacter, but was significant for coliforms. Trial (day) was si&icant for each of the parameters tested; however, there were no si&icant trial x treatment interactions. Table 4 lists the loglo mean counts for APC, coliforms, and Campylobacter. The coliform counts were significantly lower for the Control-1 group compared to the Test group and Control-2 group, which were not significantly different from each other. This trend was due to the same results occurring in only 3 of the 10 trials. It appears that on those 3 days, coliform counts increased during plant operation independent of the treatment group (thus no significant difference between the Test group and Control-2). Therefore, there were no significant differences in coliforms due to treatment. Table 5 notes the incidence of positive carcasses for both Salmonella and Campylobacter. The highest Salmonella incidence was 10% in the Control-1 group, followed by 2% in the Test group, and noSalmonella in the Control-2 group. Campylobacter incidence was 80% in the
Research Report 441
F‘LETCHERetal.
r
COhTROL-1 TREATMINT
CONTROL-I TREATMENT CONTROL-2
DAY
8
1
1
+ Percent + Total
I
0
I
O
I
o
I
O
1
o
1
5
1
5
I
5
1
1
1
5
2
1
1
0
5
5
S
5/50
1/50
o/so
40/SO
36/50
37/50
10
2
0
80
72
74
visual contamination, it would result in a significant reduction in the number of carcasses currently being removed for off-line processing without sacrificing microbiological quality of the carcasses. This system could be extremely valuable in the development of future HACCP applications, where the inspection process for visual contamination is moved to
the pre-chill check station. This approach would result in fewer carcassesbeing removed from the line, would enhance the good manufacturing concept of keeping the product moving faster along the processing lines, and would get the carcasses into the chiller faster without adverse effects on overall microbial quality or presence of pathogenic bacteria.
TABLE 6. Comments and observations by trial
TRIAL
IIC COMMENTS
1
Machines working better than normal
2
Machines working better than normal Today’s “highs”better than yesterday’s “highs”
3
No contamination deep inside bird “Best”davvet
ADDITIONAL OBSERVATIONS
4
Good performance overall
Contamination primarily around vent
S
Higher plant contamination level
High upper GI tract contents
High contamination, problems with air
Contamination in upper GI tract Line stonnages and slow downs
6
sacs
7
Moderate contamination
Contamination in upper GI tract Problem associated with “runnyguts,” not feed
8
Moderate to slightly high contamination
Contamination with coarse ingesta in upper GI tract, Large bird size variation Problems with machine maladjustments
9
Light contamination
Contamination located in upper GI tract
10
Light contamination
Contamination located in upper GI tract
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9
10
1
CO\’OI.-2
JAPR ON-LINE "REPROCESSING
442
CONCLUSIONS AND APPLICATIONS 1. On-line processing with improved inside/outsidebird washers can efficiently clean visibly-
REFERENCES AND NOTES 1. CFR, 1989. Code of Federal Regulations, Animal and Animal Products. FSISNSDA, 9 CFRCh. I11 (1-1-89 Ed.). Washington, DC.
2. Blankenship, LC., N.A. Cox, S . E Craven, AJ. Mecwi, and R.L. Wilson, 1975. Comparison of the microbiolo@cal quality of inspection-passed and fecal contamination-condemned broiler carcasses. J. Food Sci. 40:123&1238.
9. Cox, N.A., J.E. Thomson, and J.S. Bailey, 1983. Procedure for isolation and identification of Salmonella from oultry carcasses. Pages 1-18 in: USDA Agncultural Randbook No. 603. USDA, Washington, DC. 10. An aliquot of the carcass rinse fluid was added to
IT Broth Hajna and incubated at 42°C for 18-24 hr.
3. Blankenship, LC., J.S. Bailey, N.A. Cox, M.T. Musgrove, M.E Berrang, RL Wilson, M.J. Rose, and S.K. Dua, 1993. Broiler carcass re rocessing, a further evaluation. J. Food Prot. 56:983-9&.
cultures were streaked to Brilliant Samples of the Green Sulfa and Modified Lysine Iron Agar plates with 15 ppm Novobiocin. Resulting colonies with morphological characteristics of salmonellae were inoculated into Triple Sugar Iron and Lysine Iron agarslants. The identity isolates was confirmed by poly 0 of suspect -5 and poly H serology.
4. Waldroup, AL,B.M. Rathgeber, RE Hierholzer, L Smoof, S.F. Bilgul D.L Fletcher, T.C. Chen, and CJ. Wabeck, 1993. Effects of reprocessing on the microbiological condition of commercial broilers. J. Appl. Poultry Res. 2111-116.
11. Musgrove, M.T.,J.A. Cason, D.L Fletcher, NJ. Stern, N.A. Cox, and J.S. Bailey, 1993. Effect of cloacal plugging on microbial quality of partially processed broilers. Poultv Sci. 72398.
5. Powell, C., G. Blank, A. Hydamaka, and S. Dzogen, 1995. Microbiological comparison of inspection-passed and reprocessed broiler carcasses. J. Appl. Poultry Res. 4:W-31.
6. Simmons Engneering Company, P.O. Box 546, Dallas, G A 30132.
7. Dickens, J.A., N.A. Cox,J.S. Bailey, and J . E Thomson, 1985.Automated microbiologicalsampling ofbroiler
carcasses. Poultry Sci. 64:11161120. 8.Whilkmore, AD., 1993. A modified most probable number technique to enumerate total aerobes, poultry carcasses merobactena- e and -on after the whole carcass nnse procedure. PoultIy Sci. 72:2353-2357.
12. SAS Institute, 1988. SAS User's Guide for Personal Computers. Release 6.03. SAS Institute, Inc., Cary, NC. 13. Since there were no treatment X trial interactions, the treatment effects were tested using residual error. Means were separated using the Tukey test within the means option of GLM (SAS). For GmDvIobacter data, only positive carcasses were included in the analyses (negative carcasses were not included as 0 values).
ACKNOWLEDGEMENT This study was supported in part by state and Hatch funds allocated to the Georgia Agricultural Experiment Station.
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contaminated carcasses sufficiently to reduce the need for off-line reprocessingby approximately 73 to 84%. 2. On-line processing resulted in carcasses that were statistically indistinguishable from inspection-passed carcasses for mean total aerobic plate counts, total coliform counts, and Campylobacter spp. counts. 3. On-line processing did not result in any significant differences in the occurrence of Salmonella- or Campylobacter-positivecarcasses. 4. There does not appear to be any significant correlation between visible contamination and subsequent total plate counts or pathogen number. 5. On-line processing may be most applicable to the development of future HACCP-based processing and inspection programs.
A N EVALUATION OF ON-LINE"REPROCESSING" ON VISUAL CONTAMINATION AND MICROBIOLOGICAL QUALITY OF BROILERS
Primary Audience: Poultrv Processors. Researchers
I
reprocessing procedures include washing, DESCRIPTION OF PROBLEM vacuuming. and trimming, either individually At present, the USDA allows for the offline reprocessing of visually contaminated carcasses. These reprocessing procedures include the removal ofthe bird from the processing line, reprocessing in an approved off-line area for removal of contamination, then chlorination, and finally reinspection. Approved 1
To whom correspondence should be addressed
I .
or in combination [I]. Several studies have shown that off-line reprocessed carcasses are microbiologically indistinguishable from inspection-passed carcasses [2,3,4,5]. Waldroupet al. concluded from a large multi-state study that carcasses subjected to USDA-approved reprocessing
Downloaded from http://japr.oxfordjournals.org/ at umontanalawschool on April 8, 2015
D.L. FLETCHER' and E. W CRAIG Depamnent of Poultry Science, The University of Georgia, Athens, GA 30602 Phone: (706) 542-2476 F M : (706) 542-2475 J. W ARNOLD USDA-ART, Richard B. Russell Agricultural Research Center, Athens, GA 30613
Research Report 437
FLETCHER et al.
All bird carcasses used in this study were removed from the line as the carcasses exited the inside/outside bird washer. Samples were collected only on the night shift of a Monday, Tuesday, or Wednesday over approximately a 4-wk period until 10 replicate trials were completed. Only fully dressed, intact, and otherwise defect-free carcasses were used (to prevent secondary identification during subsequent “blind“ scoring). Water chlorine levels in the inside/outside bird washer were determined at the beginning and end of each trial. In each trial (day), carcasses were collected according to one of three experimental treatment groups of 15 carcasses each: a pretest control group (Control-1), a test group, and a post-test control group (Control-2). The Control-1 group consisted of 15 inspectionpassed carcasses removed from the line at random following the inside/outside bird washer. The test group consisted of 15 carcasses identified by the USDA line inspectors as being visually contaminated and subject to off-line reprocessing. These 15 carcasses were left on the lime, the shackle marked, and the carcasses allowed to proceed with the inspection-passed carcasses until removal from the line following the inside/outsidebird washer. The post-test Control-2 group was then collected as described for the Control-1 group. This second control group was collected to ensure against line or flock changes over time, such as bacteria accumulation along the line or sudden pockets of heavily contaminated carcasses, which would result in apparent treatment effects. As each group of 15 carcasses was being removed from the line, 5 were randomly selected, placed in pre-coded bags, double bagged, and packed on ice for transport to the lab for microbiological sampling and analyses the next day. The remaining 10 carcasses from each group were also placed in pre-coded bags but were hung by one leg on a reprocessing rack. After the three groups were collected, the carcasses were randomized across groups, the bags removed, and the carcasses subjected to individual carcass reinspection by the plant USDA Inspector-in-Charge (IIC) at the reprocessinginspection area (under adequate inspection lighting). Care was taken to prevent surface drying and cross contamination (by bagging) and temperature factors from influ-
MATERIALS AND METHODS The study was conducted in a commercial processing plant equipped with the Simmons’ Advanced System for Evisceration (SASE) [6] installed on one line running at 70 birddmin. This system includes a gizzard harvester (Model SGH-ZOO), cropper/neck breaker (Model SCR-2300), lung remover (Model SLR-8OOO), and a chlorinated inside/outside bird washer (Model SBW-3100) positioned just prior to the plant pre-chill check station.
Downloaded from http://japr.oxfordjournals.org/ at umontanalawschool on April 8, 2015
are as safe microbiologically as those that pass inspection [4]. A study conducted in Canada reported similar results [5]. Currently, many processing plants average between 2 to 5% reprocessing (20,OOO to 50,000 birddwk). A large proportion of the carcasses sent to reprocessing are contaminated with ingesta usually removed during reprocessing. It has been proposed that improvements in equipment design and on-line washing could greatly reduce the number of carcasses sent to off-line reprocessing. Under such a scheme, visually contaminated carcasses would not be removed from the line at the current inspection station but would be allowed to proceed through evisceration and a chlorinated inside/outside bird washer prior to examination for visual contamination at a checkpoint prior to entering the chiller. Carcasses still showingvisual contamination at the pre-chill checkpoint would then be removed for manual off-line reprocessing. On-line processing would have the potential advantages of reducing the number of carcasses removed from the line for minimal reprocessing as well as allowing more carcasses to enter the chiller in less time. Advances in equipment design have resulted in processing systems which reduce contamination during evisceration and which are better able to remove visual contamination through more thorough inside and outside bud washing. The purpose of this project was to evaluate one of these new systems in a commercial processing plant environment to determine if the need for off-line reprocessing could be reduced or eliminated. Carcasses showing visual contamination would be subjected to on-line processing and chlorination and then compared to inspection-passed carcasses both for the presence of visible contamination and for microbiological examination.
438
Control-2), and 10 replicate trials (days). For the visual scoring, there were 10 carcasses per treatment and trial (total n = 300). For the microbiological data, there were 5 carcasses per treatment and trial (total n = 150). The microbiological data was corrected to an equivalent of 100 mL rinse recovery and converted to loglo units for statistical analyses. Data were analyzed using the analyses of variance option of the GLM procedure of the Statistical Analyses System (SAS) computer program for the main effects of treatment and trial [12,13].
RESULTS AND DISCUSSION Under average conditions, it took approximately 20 min to collect each of the two control samples, and about 30 min to collect the test samples. The limiting factor on the control groups was the time necessary to remove and handle each bird. The Test group took longer to sample since the inspection-failed carcasses were identified at only one of the two inspection stations. Also, as the inspection-failed carcasses were removed from the line, they were examined and confirmed to be otherwise intact and free of defects. Since normal reprocessing rates are less than 3%, it would take a minimum of approximately 21 min to obtain the required 15 carcasses. Therefore, the average sampling time for all 45 carcasses ranged from about 70 to 120 min. During this time, approximately 5000 to 8OOO carcasses will have passed down the line, meaning that the 45-bird sample represented less than 1% of the line throughput. This would also indicate that the impact of the test carcasses on the subsequent data would be negligible compared to other variables in bird, flock, and normal processing. Chlorine levels were targeted to range between 20 and 30 pprn in the inside/outside bird washer and was monitored before and after sampling. The results of the chlorine analyses appear in Table 1.Chlorine averaged 24.8 ppm at the beginning and 27.1 pprn after sampling. Chlorine never went below 20 ppm, but values did exceed 30 ppm on 3 of the sample days. The results for the reinspection scores by trial and percent summary for the combined trials appear in Table 2. In the two control groups, a total of 5 and 7% of the originally inspection-passed carcasses failed reinspec-
Downloaded from http://japr.oxfordjournals.org/ at umontanalawschool on April 8, 2015
encing the reinspection. The reinspection was conducted such that the IIC was "blind relative to treatment identification. Each carcass was individually scored for the presence or absence of visible contamination appearing as digestive tract contents, specks, or tiny smears of ingesta or feces. If carcasses were identified as being visibly contaminated, the IIC made a subjective score based on the following criteria: Score 1 - visible contamination was "lod' if only one identitiable speck or smear of ingesta or feces of any size measured 1/16 in. or less in its greatest dimension; such contamination would be visible only under close examination not possible under normal line speeds and inspection conditions; Score 2 - visual contamination was "high" or obvious if more than one identifiable speck or smear of ingesta or feces were noticed and/or if one or more speck or smear were more than 1/16 in. at its greatest dimension; such contamination would likely be detected under normal line inspection speeds and conditions. The subjective visual score did not imply any quantitative assessment of contamination,but rather the ease of visual detection. Time for off-line reinspection was not limited and normally ranged from 5 to 11min. The 15 carcasses identified for microbiological evaluation were transported on ice and held under refrigeration for approximately 10 to 12 hr prior to evaluation. Carcasses were individually weighed; carcasses were sampled by rinsing in the individual polyethylene bags with 100 mL of sterile phosphate-buffered saline and shaken for 1min according to the procedure of Dickens et al. [7l.The carcasses were removed, and the rinse volume left in the bag was measured. For total aerobes, 1mL of the rinse was plated onto aerobic plate count agar by 10-fold dilution series and incubated at 37°C for 48 hr. Total coliforms were enumerated using the 3-tube MPN with Brilliant Green Bile 2% media [a]. The presence of Salmonella was determined using the procedure of Cox et al. [9, 101. Cmpylobacter species were determined using an aliquot of the carcass rinse fluid which was centrifuged (SO00 rpm, 10 min, 4°C) and resuspended in PBS. A 100-pL sample was then plated onto Cefex media and incubated at 42°C for 24 to 32 hr [ll]. The experimental design consisted of three treatments (Control-1, Test group, and
ON-LINE, "REPROCESSING"
Research Report 439
FLETCHER et al.
BEGINNING
DAY
END
(3 @pm)
I
1
22
24
2
23
24
3
24
21
4
26
30
5
24
175
6
295
8
I
9 10
Mean
1
23 2
I I I
6 225 275
24.8
365
I 1 I I I
29 27 31
31 27.1
I I I I I
tion. Of the reinspection-failed carcasses, only one of the five in Control-1 was considered obvious or "high" (Score 2), while five of the seven reinspection-failed carcasses in Control-2 were considered obvious or "high" (Score 2). These results indicate that between 5 and 7% of the carcasses originally inspection-passed on the line were either missed during inspection or picked up some
TABLE 2. Summary of inspection scores (failure occurrence/lO carcasses) by trial and percent summary of the combined trials for the Control-1, Test, and Control9 groups
*Score 1: Visible contamination was "low" if only one identifiable speck or smear of ingesta or feces of any sizc measured 1/16 in. or less in its greatest dimension; such contamination would be visible only under close examinatior not possible under normal line speeds and inspection conditions. BScore 2: Visual contamination was "high"or obvious if more than one identifiable speck or smear of ingesta or feces were noticed and/or if one or more speck or smear were more than 1/16 in. at its greatest dimension; such rnntiminntinn wniild likplv he detected under normal line insuection soeeds and conditions.
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I I I
1
7
contamination during viscera removal, washing, or handling prior to reinspection. Half of the reinspection-failed carcasses in the two control groups were at a level which should be obvious under normal line inspection conditions (Score 2) as opposed to off-line reinspection with no time limit. For the inspection-failed and on-line reprocessed carcasses (Test group), 33 failed reinspection, and of those 33 visually contaminated carcasses, 19 were considered obvious or ''high'' (Score 2). These results indicate that 67% of the carcasses could have been processed on-line. A comparison of the Score 1 and Score 2 results indicate that 81% of the carcasses originally inspection-failed would have been cleaned sufficiently to have passed later on-line inspection at the pre-chill check station. By comparing the visual contamination results of the two control groups with the Test group, it appears that on-lineprocessing could reduce the number of carcasses requiring offl i e reprocessing by approximately 73 to 84%. This estimate is based on the average of a 6% control failure with a 67% clean-up rate for totalvisual contamination (6 + 67 = 73%) or a 3% control failure and 81% clean-up rate based on practical ability to discern visual con-
ON-LINE "REPROCESSING"
440
Control-1 group, followed by 74% in the Control-2 group, and 72% in the Test group. These results clearly demonstrate that there were no negative effects in regards to these two organisms regarding on-lineprocessing as opposed to inspection-passed carcasses. It also appears that visible contaminationhas no significant relationship to either total bacterial counts or to the presence of either Salmonella or Campylobacter. A summary of the IIC comments and observations for each trial appears in Table 6. As would be expected,variations in the visible contaminationload and plant operationvaried across trials. The only trial in which operational problems occurred was Trial 8 where maladjusted evisceration equipment and high contamination loads were combined. Since treatment was not significant for any of the parameters tested, nor were there any trial x treatment interactions,the data were analyzed across trials. However, it should be noted that the significant effect for coliforms existed in only 3 of the 10 trials, with exactly the same pattern (Le., Control-1 was si&icantly lower than either the Test group or Control-2,which were not significantly different from each other in Trials 3, 6, and 7). There were no significant differencesin any of the other seven trials. These results indicate that although the on-line processing did not remove all of the
TREATMENT
n
TRIAL (Day)
TREATMENT X TRIAL
P Carcass weight (g)
149
0.3363
0.0278
0.0705
APC
149
0.7665
0.0001
0.2560
Coliforms
149
0.0043
0.0001
0.1122
CamDvlobacter SPP.
113
0.6587
0.0001
0.0978
CONTROL-1
TREATMENT
CONTROL3
APC
5.39
Log10 5.41
5.43
Coliforms
4.19b
4.52a
4.48a
2.90
3.23
3.15
spp.
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tamination at commercial processing plant line speeds (3 + 81 = 84%). The results of the analyses of variance for carcass weight, aerobic plate count (APC), coliform count, and Campylobacter counts appear in Table 3. Treatment was not significant for carcass weight, APC, or Campylobacter, but was significant for coliforms. Trial (day) was si&icant for each of the parameters tested; however, there were no si&icant trial x treatment interactions. Table 4 lists the loglo mean counts for APC, coliforms, and Campylobacter. The coliform counts were significantly lower for the Control-1 group compared to the Test group and Control-2 group, which were not significantly different from each other. This trend was due to the same results occurring in only 3 of the 10 trials. It appears that on those 3 days, coliform counts increased during plant operation independent of the treatment group (thus no significant difference between the Test group and Control-2). Therefore, there were no significant differences in coliforms due to treatment. Table 5 notes the incidence of positive carcasses for both Salmonella and Campylobacter. The highest Salmonella incidence was 10% in the Control-1 group, followed by 2% in the Test group, and noSalmonella in the Control-2 group. Campylobacter incidence was 80% in the
Research Report 441
F‘LETCHERetal.
r
COhTROL-1 TREATMINT
CONTROL-I TREATMENT CONTROL-2
DAY
8
1
1
+ Percent + Total
I
0
I
O
I
o
I
O
1
o
1
5
1
5
I
5
1
1
1
5
2
1
1
0
5
5
S
5/50
1/50
o/so
40/SO
36/50
37/50
10
2
0
80
72
74
visual contamination, it would result in a significant reduction in the number of carcasses currently being removed for off-line processing without sacrificing microbiological quality of the carcasses. This system could be extremely valuable in the development of future HACCP applications, where the inspection process for visual contamination is moved to
the pre-chill check station. This approach would result in fewer carcassesbeing removed from the line, would enhance the good manufacturing concept of keeping the product moving faster along the processing lines, and would get the carcasses into the chiller faster without adverse effects on overall microbial quality or presence of pathogenic bacteria.
TABLE 6. Comments and observations by trial
TRIAL
IIC COMMENTS
1
Machines working better than normal
2
Machines working better than normal Today’s “highs”better than yesterday’s “highs”
3
No contamination deep inside bird “Best”davvet
ADDITIONAL OBSERVATIONS
4
Good performance overall
Contamination primarily around vent
S
Higher plant contamination level
High upper GI tract contents
High contamination, problems with air
Contamination in upper GI tract Line stonnages and slow downs
6
sacs
7
Moderate contamination
Contamination in upper GI tract Problem associated with “runnyguts,” not feed
8
Moderate to slightly high contamination
Contamination with coarse ingesta in upper GI tract, Large bird size variation Problems with machine maladjustments
9
Light contamination
Contamination located in upper GI tract
10
Light contamination
Contamination located in upper GI tract
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9
10
1
CO\’OI.-2
JAPR ON-LINE "REPROCESSING
442
CONCLUSIONS AND APPLICATIONS 1. On-line processing with improved inside/outsidebird washers can efficiently clean visibly-
REFERENCES AND NOTES 1. CFR, 1989. Code of Federal Regulations, Animal and Animal Products. FSISNSDA, 9 CFRCh. I11 (1-1-89 Ed.). Washington, DC.
2. Blankenship, LC., N.A. Cox, S . E Craven, AJ. Mecwi, and R.L. Wilson, 1975. Comparison of the microbiolo@cal quality of inspection-passed and fecal contamination-condemned broiler carcasses. J. Food Sci. 40:123&1238.
9. Cox, N.A., J.E. Thomson, and J.S. Bailey, 1983. Procedure for isolation and identification of Salmonella from oultry carcasses. Pages 1-18 in: USDA Agncultural Randbook No. 603. USDA, Washington, DC. 10. An aliquot of the carcass rinse fluid was added to
IT Broth Hajna and incubated at 42°C for 18-24 hr.
3. Blankenship, LC., J.S. Bailey, N.A. Cox, M.T. Musgrove, M.E Berrang, RL Wilson, M.J. Rose, and S.K. Dua, 1993. Broiler carcass re rocessing, a further evaluation. J. Food Prot. 56:983-9&.
cultures were streaked to Brilliant Samples of the Green Sulfa and Modified Lysine Iron Agar plates with 15 ppm Novobiocin. Resulting colonies with morphological characteristics of salmonellae were inoculated into Triple Sugar Iron and Lysine Iron agarslants. The identity isolates was confirmed by poly 0 of suspect -5 and poly H serology.
4. Waldroup, AL,B.M. Rathgeber, RE Hierholzer, L Smoof, S.F. Bilgul D.L Fletcher, T.C. Chen, and CJ. Wabeck, 1993. Effects of reprocessing on the microbiological condition of commercial broilers. J. Appl. Poultry Res. 2111-116.
11. Musgrove, M.T.,J.A. Cason, D.L Fletcher, NJ. Stern, N.A. Cox, and J.S. Bailey, 1993. Effect of cloacal plugging on microbial quality of partially processed broilers. Poultv Sci. 72398.
5. Powell, C., G. Blank, A. Hydamaka, and S. Dzogen, 1995. Microbiological comparison of inspection-passed and reprocessed broiler carcasses. J. Appl. Poultry Res. 4:W-31.
6. Simmons Engneering Company, P.O. Box 546, Dallas, G A 30132.
7. Dickens, J.A., N.A. Cox,J.S. Bailey, and J . E Thomson, 1985.Automated microbiologicalsampling ofbroiler
carcasses. Poultry Sci. 64:11161120. 8.Whilkmore, AD., 1993. A modified most probable number technique to enumerate total aerobes, poultry carcasses merobactena- e and -on after the whole carcass nnse procedure. PoultIy Sci. 72:2353-2357.
12. SAS Institute, 1988. SAS User's Guide for Personal Computers. Release 6.03. SAS Institute, Inc., Cary, NC. 13. Since there were no treatment X trial interactions, the treatment effects were tested using residual error. Means were separated using the Tukey test within the means option of GLM (SAS). For GmDvIobacter data, only positive carcasses were included in the analyses (negative carcasses were not included as 0 values).
ACKNOWLEDGEMENT This study was supported in part by state and Hatch funds allocated to the Georgia Agricultural Experiment Station.
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contaminated carcasses sufficiently to reduce the need for off-line reprocessingby approximately 73 to 84%. 2. On-line processing resulted in carcasses that were statistically indistinguishable from inspection-passed carcasses for mean total aerobic plate counts, total coliform counts, and Campylobacter spp. counts. 3. On-line processing did not result in any significant differences in the occurrence of Salmonella- or Campylobacter-positivecarcasses. 4. There does not appear to be any significant correlation between visible contamination and subsequent total plate counts or pathogen number. 5. On-line processing may be most applicable to the development of future HACCP-based processing and inspection programs.