On-line real time aid to the veriwcation of CCP compliance in beef slaughter HACCP systems

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1 Food Control 18 (2007) On-line real time aid to the veriwcation of CCP compliance in beef slaughter HACCP systems J.H. Ryan Dublin Institute of Technology, School of Food Science and Environmental Health, Faculty of Tourism and Food, Ireland Received 23 October 2005; received in revised form 22 February 2006; accepted 24 February 2006 Abstract This study investigated the use of an on-line monitoring and display system in a beef slaughtering plant. The objective was to determine what information was possible and what benewts could be forthcoming that would assist compliance with HACCP requirements. The system was to be low tech, user friendly and economical. The study was carried out over eleven days, spread over 13 weeks; 75 cattle were observed each day for visible faecal, rumen and ingesta contamination over six sites per carcass side. Spinal cord presence in the exposed spinal channel was also observed. Over the course of the study the number of carcasses with visible contaminated was reduced from 76% to 33.33%; visible contamination attributed to dehiding operations was reduced from 54.67% to 24.00%, visible contamination attributed to evisceration operations was reduced from 44% to 16.67%. A signiwcant reduction in the magnitude of visible contamination per carcass was also observed. Spinal cord presence was reduced from 6% to 0%. The system facilitated the identiwcation of the most probable causative process stages, the implementation of on-line real time immediate and long term corrective action and the establishment of a single process CCP Elsevier Ltd. All rights reserved. Keywords: Beef slaughter; Carcass contamination; Food safety; HACCP; On-line monitoring 1. Introduction Carcass contamination, arising out of dehiding and evisceration operations, is of major concern to food safety due to the possible presence of human pathogens. Being enteric these pathogens are found both in the viscera and rumen contents and in the faeces of bovine animals and Wnd their way onto underlying Xesh during the dehiding and evisceration of cattle (Bell, 1997; Bolton, Doherty, & Sheridan, 2001; Gill & Mc Ginnis, 1999; Gill, Mc Ginnis, & Baldoni, 1995a; Sheridan, 1998). Similar concern is directed towards the presence of spinal cord material due to the infective hazard posed by the bovine spongiform encephalopathy prion (BSE) found in the central nervous system (spinal cord) and its association with the new variant Creutzfeldt * Address: 26 Woodside, Dodder Park Road, Rathfarnham, Dublin 14, Ireland. Tel.: address: jhryan@eircom.net Jacob disease (vcjd) (Bruce et al., 1997; Collinge, Sidle, Goodson, Savell, & AcuV, 1996) Visible versus bacterial contamination This study was undertaken with the assumption that those events which are responsible for visible contamination have a close association with those events responsible for bacterial contamination. Therefore, practices which encourage the prevention or minimisation of visible contamination will evect a similar reduction in carcass bacterial contamination thereby contributing to a reduction in meat bacterial safety hazards. IdentiWcation of visible contamination will certainly highlight inevective practices and improper process operations but a cautionary reference needs to be made with respect to any preconceived relationship between visible contamination and microbiological contamination. Schnell et al. (1995) concluded that as far as dehairing carcasses /$ - see front matter 2006 Elsevier Ltd. All rights reserved. doi: /j.foodcont

2 690 J.H. Ryan / Food Control 18 (2007) were concerned the absence of visual contamination was not well-correlated with the bacterial cleanliness of beef carcasses, although the study did propose that over an extended period of time, using exclusive processing facilities for dehaired animals, it could be anticipated that removing the dirt, faeces and hair prior to hide removal should decrease carcass surface pathogens. Gill, Mc Ginnis, and Baldoni (1995b) concluded that commercial trimming and standard washing operations were not evective means of decontaminating beef carcasses. Jericho, Bradley, Gannon, and Kozub (1992) concluded that there was only a very weak correlation between carcass demerit score (visible contamination) and MPNGU/CM 2 (most probable number growth units per square centimetre) at a cluster site (bacterial contamination) on commercial beef carcasses. A study by Gill et al. (1995a) revealing a reduction of E. coli as a result of trimming and washing also showed that posterior carcass areas were still heavily contaminated post trimming and washing (a similar Wnding was identiwed for total counts with respect to the anterior carcass areas). It may therefore be proposed that once microbiological contamination occurs in the initial processing stages it s diycult to evect satisfactory bacterial reductions in later processing stages. Removal of visible carcass contamination does not erase any food safety issues which may arise from non-compliant processes and/or poor operator work practices; just because bacteria cannot be seen does not mean there not there. Additionally, attempts at removal may only lead to the spread of the contamination thereby exacerbating any associated microbiological hazards. Indeed, the uncertainty surrounding the ability of traditional carcass decontamination (trimming) to evect carcass surface bacterial reduction has led to the development of a myriad of intervention systems such as steam vacuuming e.g. Vac-San (Gill & Bryant, 1997), steam pasteurisation (Nutsch et al., 1998), hot water washing (Gill, Bryant, & Bedard, 1999), carcass surface treatment with organic acids (Smulders & Greer, 1998), etc Holistic hygienic culture Nonetheless, a decrease in visible carcass faecal contamination should be accompanied by decreasing trends in microbial counts on the basis that the system will foster a process of continuous improvement thereby reducing the risk of beef associated food-borne illness to consumers (Tergney & Bolton, 2005). Whilst not dewnitively pinpointing to lower carcass bacterial loading the absence of visible faecal contamination does rexect a greater tendency towards compliance of a more holistic hygienic process, the institutionalisation within the slaughterhouse of a more robust GHP/GMP pre-requisite program and the reduction in contamination due to aerosols, equipment and personnel [often cited as important sources of carcass bacterial contamination, Le Jeune and Christie (2004), Schnell et al. (1995)]. Certainly, Hudson, Mead, and Hinton (1996) identiwed a lowering of microbiological contamination with the implementation of a robust GHP/GMP pre-requisite program. The expected downward trend in carcass contamination should be accompanied by a similar decreasing trend in carcass surface bacterial counts. However, due to resource limitations no microbiological analysis was undertaken in this study. To ascertain whether such a link exists, reference was made to two papers involving online monitoring. The Wrst study by Bolton, Oser, Cocoma, Palumbo, and Miller (1999) on pigs indicated that there was a strong correlation between visible carcass contamination and total plate count. The second study by Tergney and Bolton (2005) on beef carcasses identiwed no correlation between visible carcass faecal contamination and TVC, E. coli, Enterobacteriaceae and total coliform counts; nonetheless the study did show signiwcant decreases for E. coli, Enterobacteriaceae and total coliform counts. Such downward trends for indicator organisms and hence for potential pathogens such as E. coli 0157:H7 (and other serotypes) and Salmonella spp. is an encouraging raison d etre for the installation of an online monitoring and display system in any abattoir HACCP To be evective a food safety management system as exempliwed by HACCP and mandatory under 2001/471/EC requires monitoring and control (of critical limits) of those process stages deemed critical to food safety. These process stages, identiwed as critical control points (CCP s), must be monitored and all non-compliances immediately corrected by removing the ovending material, by re-skilling stav and by rectifying identiwed process or equipment faults. The standard procedure of monitoring in the majority of beef abattoirs involves visual inspection by an operative who generally also trims ov the contamination. Generally there is little or no records or data generated regarding the level of non-compliance. There appears to be no immediate feed back loop to the primary causative process stage and the learning process is at best inevective and at worst non-existent. The online monitoring and display system envisaged would allow for monitoring of processed carcasses, identiwcation of non-compliances and facilitation of both immediate and long term corrective action. Centralising responsibility for food safety into a single process stage where critical limits of visual contamination can be readily monitored and correctively acted upon in real time can be accommodated. Resources can be funnelled into one area and across a relatively small number of operatives. 2. Materials and methods 2.1. Monitoring and display unit A push button station consisting of seven push buttons numbering 1 7 was attached to the inspection stand. Each

3 J.H. Ryan / Food Control 18 (2007) Table 1 Illustrates the link between beacons, carcass inspection sites, process stages and contamination types Beacon number Carcass inspection area Process stages Contamination observed as Causative category 1 and 2 H/Q leg [Dehiding] Left and Right Faecal specks and smears and stains found on leg and rump Dehiding Leg Dehide 3 Flank and brisket Flanking Faecal specks and smears and stains found along each Dehiding [Dehiding] Xank and along the brisket/pelvic mid-line 4 Shank and neck Necking and Faecal specks and smears and stains found around the Dehiding [Dehiding] Shanking foreleg and neck regions 5 Anus and rump Bunging and Larger faecal stains and patches mainly found on the rump Evisceration [Evisceration] bagging and inside region 6 Brisket and rib cage [Evisceration] Evisceration Belly Large faecal stains and patches and yellowish/brownish/greenish stains and patches on brisket and inside rib cage Evisceration 7 Spinal channel [Spinal cord] Spinal cord removal Cylindrically shaped soft material hanging within spinal bone column with possible threadlike attachments Spinal cord removal button was linked to an individual beacon sounder and a central audible visual alarm. Activation of a push button, by the in-house on-line inspector, switched on both the corresponding beacon and the central alarm and stopped any further movement of the slaughter line. If activated this central alarm and the individual beacon(s) could only be deactivated and the slaughterline remobilised by activating a central control unit; key s for this central control unit were held by the abattoir manager and the abattoir supervisor. Each push button and the beacon to which it was linked corresponded to a speciwc carcass inspection site. The beacons were positioned in close proximity to those speciwc process stages associated with known carcass surface contamination Carcass inspection sites The benewts of an on-line monitoring and display system are very much dependant upon the ability to be able to observe the contamination as well as being able to link the contamination found to a particular process stage and hence to a particular causative operative/procedure/process equipment. Only then can immediate on-line corrective action be undertaken and long term stav re-skilling, implemented. Seven carcass sites were chosen for inspection (Table 1) Interpretation of contamination types It was important to interpret contamination types and to link these with their associated causes (Table 1) Cattle Cattle were all steers, from variable and mixed breeds, with a kill out weight range of kg. Transport to the lairage involved both professional hauliers and individual farmers who transported single animals from their own farms. The Wrst eight days of observation were carried out during the four weeks of April while the last three days of observation were undertaken during the last week of June. No direct link between weather (rain) and visible carcass contamination was undertaken. In general all cattle slaughtered during the observation days would have been rested in the lairage facilities for a minimum of two hours prior to slaughter. All cattle supplies would have been pre-graded as per the Department of Agriculture s Dirty/Clean Policy prior to slaughter with grades 1, 2 or 3 been acceptable for slaughter. Such pre-grading would have Wltered out heavily soiled cattle for slaughter; nonetheless the degree of visible contamination on carcasses presented for slaughter would have been variable Format of research The study was carried out over eleven days, spread over 13 weeks, during which the carcasses of 75 cattle (150 carcass sides) were observed each day for visible faecal, rumen and ingesta contamination over six sites per carcass side. Spinal cord presence in the exposed spinal channel was also observed. Each sample of 150 carcass sides consisted of the Wrst 75 cattle presented for slaughter over the morning period from am to am within which a 15 min morning tea/covee break from am to am was undertaken. Observations were documented both by the author and by the in-house visual inspector Recording Each carcass side was monitored for faecal and ingesta contamination and for the presence of spinal cord material. The in-house on-line inspector ensured that contamination discovered resulted in the relevant beacon being activated. Activations were documented by the in-house on-line inspector. The author similarly documented all carcass contaminations. Comparison of both sets of observations (i.e. one set represented by the observations of the author and the other set represented by those observations of the in-house on-line inspector) would identify the level of convergence or divergence between both individuals. These Wgures can only be relied upon if all the corresponding observations for the

4 692 J.H. Ryan / Food Control 18 (2007) seven carcass sites from each set are an identical match. To ascertain what the actual diverences were between both sets of observations a match/mismatch analysis was undertaken for all corresponding observations from both sets (Fig. 4) Magnitude of contamination The magnitude of visible contamination per carcass was quantiwed by documenting visible contamination as occurring at one, two, or three or more sites on the carcass (Table 2) Analysis of results Using Excel Regression Analysis and SPSS signiwcance is taken at the 5% level (p <0.05). 3. Results and discussion 3.1. Contamination Visible carcass contamination Over the course of the study the number of carcasses contaminated with visual faecal and ingesta contamination was signiwcantly reduced (p < 0.05) from 76% on observation day 1 to 33.33% on the Wnal day; visible contamination attributed to dehiding operations was signiwcantly reduced (p < 0.05) from 54.67% to 24.00%, while visible contamination attributed to evisceration operations was signiwcantly reduced (p < 0.05) from 44% to 16.67% over the same period (Fig. 1). Spinal cord presence was signiwcantly reduced (p < 0.05) from 6% to 0% over the same period (Fig. 1). The number of carcasses visibly contaminated before intervention and implementation of the on-line monitoring and display system was 73.3% (mean: day 1 and 2), this dropped, as a result of the intervention system, to 42.7% (mean: day 3 11); this reduction was signiwcant at the 5% level (Fig. 2). Final visible contamination levels due to evisceration were fairly stable from day to day whereas Wnal visible contamination levels due to dehiding Xuctuated from day to day and indeed appear to have inxuenced a similar variable pattern in the overall total visible carcass contamination values. This may be due to the fact that whilst visible carcass contamination due to both evisceration and dehiding is inxuenced by operator capabilities, visible carcass contamination due to dehiding may be more directly inxuenced by hide contamination which by its very nature is very variable and inconsistent. It would appear that hide contamination pre slaughter has an important inxuence on post slaughter visible carcass contamination both directly and indirectly via aerosols, equipment and operatives and reinforces the importance of clean cattle supplies; once visible contamination occurs in the initial processing stages its diycult to evect a satisfactory visible contamination level in later processing stages (Gill et al., 1995; Gill and Mc Ginnis, 1999). Table 2 Illustrates the reduction in carcasses contaminated and the magnitude of that contamination Observation dates Carcass contamination Total (%) % with 7 3 Sites % with 2 Sites % with 1 Sites 1 (04/04/2005) (05/04/2005) (11/04/2005) (12/04/2005) (18/04/2005) (19/04/2005) (25/04/2005) (26/04/2005) (27/06/2005) (28/06/2005) (29/06/2005) % Carcasses Contaminated 80% 70% 60% 50% 40% 30% 20% 10% 0% Carcasses Contaminated Observation Days Total Carcasses Contaminated Contamination from Dehiding Contamination from Evisceration Contamination from Spinal Cord Fig. 1. Illustrates the reduction in carcasses contaminated.

5 J.H. Ryan / Food Control 18 (2007) % Before & After Implementation of Intervention System % Contamination 60.0% 40.0% 20.0% 0.0% Carcass Sides H/Q Leg Flank & Brisket Neck & Shank Anus & Rump Brisket Rib Cage SRM Before Intervention 73.3% 25.7% 31.3% 26.0% 26.7% 16.3% 9.0% 7.7% After Intervention 42.7% 13.2% 11.7% 11.8% 8.5% 8.9% 5.0% 0.0% Carcass Inspection Sites Fig. 2. Illustrates the reduction in carcass contamination before and after intervention of the on-line monitoring and display system. % Carcasses Contaminated 80% 70% 60% 50% 40% 30% 20% 10% 0% Magnitude of Carcass Contamination Observation Days Total Carcass Contamination Carcass Contamination at 3 or more Sites Carcass Contamination at 2 Sites Carcass Contamination at 1 Site Fig. 3. Illustrates a reduction in both the number of carcasses contaminated and the magnitude of that contamination Magnitude of visible carcass contamination As well as evecting a reduction in the number of carcasses visibly contaminated the on-line monitoring and display system achieved signiwcant reductions in the magnitude of such visible contamination. The magnitude of visible contamination per carcass was quantiwed by documenting visible contamination as occurring at one, two, or three or more sites on the carcass. Over the course of the study visible contamination at 3 or more carcass sites fell signiwcantly from 12% to 2.67%, at 2 sites from 30.67% to 7.33% and at one site from 33.33% to 23.33% (Fig. 3) Process stage contamination The reductions observed for each process stage over the 11 day observation period were all signiwcant at the 5% level. Reduction in carcasses visibly contaminated due to dehiding; H/Q Leg reduced from 28% to 10%, Flank and Brisket reduced from 21.33% to 8.67% and Neck and Shank reduced from 26.67% to 6.67% over the study period. Reduction in carcasses visibly contaminated due to evisceration; Anus and Rump reduced from 27.33% to 8.00%, Brisket from 16.00% to 7.33% and Rib Cage from 8.67% to 5.33% over the study period. The presence of spinal cord material in processed carcasses was reduced from 6.00% to 0% over the study period (Table 3). The study provided accurate information on the levels of visible carcass contamination originating from each process stage and facilitated both trend and training gap analysis with respect to operative compliance of standard operating procedures Competency of in-house inspector Comparisons can only be relied upon if all the corresponding observations for the seven carcass sites from each set are identical; i.e. the set of observations recorded by the in-house on-line inspector and those of the author. To ascertain what the actual diverences were between both sets of observations a match/mismatch analysis was undertaken for all corresponding observations from both sets. The decline in the diverence between both observation sets was signiwcant at the 5% level. It should be noted that the eleven observation days consisted of two distinct periods; observation days one to eight and observation days nine to eleven with a nine week gap in between. The eyciency of the in-house on-line inspector in detecting visual carcass contamination appears to have diminished somewhat during this gap period as was witnessed by a sudden increase in diverence observed on observation day nine and to a lesser extent over observation

6 694 J.H. Ryan / Food Control 18 (2007) Table 3 Illustrates the % of carcasses contaminated at each process stage and the magnitude of that contamination over the eleven days of observation Test day H/Q leg dehide (%) Anufs/rump EV (%) Flank and brisket dehide (%) Neck and shank dehide (%) Brisket EV (%) Rib cage EV (%) SRM (%) % Sides % with 7 3 Sites % with 2 Sites % with 1 Site days ten and eleven in comparison to the steady downward trend as was witnessed over the Wrst period of observation days one to eight. The inxuence of the author may have been a contributory factor and further work would need to be done with respect to the sustainability of in-house competencies to detect visual carcase contamination in the absence of third party presence (Fig. 4) Response over time The daily observation sample of 150 carcass sides was divided into Wve groups of 30 carcass sides each. With an hourly kill rate of approximately 30 cattle, each 30 carcass side group equates to approximately one half hour. The contamination level for each group was identiwed. SigniWcant reductions (p < 0.05) in carcass contamination were observed both from day to day as well as from group to group within each day. The on-line monitoring and display system had supported on-line real time behavioural corrective action through a process of learning (Figs. 5 and 6). It was observed that the Wrst groupings each morning witnessed greatest visible contamination than the later groupings. It was apparent that the learning process was active and positive; once corrective action was initiated it was sustainable throughout the daily test period. The ability to achieve low levels of visible carcass contamination throughout the daily test period was very much dependent on initial inspection and subsequent correction action; improvement was dependent on detection and subsequent intervention. Each test period included a short break of 15 min; no evidence was found to show a link between the morning tea break and a lowering of operative carcass dressing skills. Whether a longer one hour lunch break would have any inxuence over carcass dressing skills was not examined System installation The cost of beacons, wiring, central control alarm, push button panel, on ov control switch, extra lighting at inspection stand, was less than D4000. The complete system was installed by in-house maintenance personnel over a weekend. Training and re-skilling of in-house on-line inspector(s) and process operatives as well as considerable supervisory and management input represented additional investment into ensuring evective operation of the system. Slowing down production throughputs (at least in the initial stages) also represented additional investment costs. 25% 20% Observation Differences - Author & In-House Inspector - Carcass Sides y = x R 2 = % Difference 15% 10% 5% 0% y = e x R 2 = Series % 22.00% 13.33% 14.67% 8.00% 7.30% 8.67% 2.00% 14.00% 9.33% 6.00% Observation Days Fig. 4. Illustrates the actual % diverence between both sets of recorded observations over the 11 day test period with respect to carcass sides.

7 J.H. Ryan / Food Control 18 (2007) Carcasses Contaminated Carcass Contamination - Time Trend Day 1 to 6 1st 30 Sides 2nd 30 Sides 3rd 30 Sides 4th 30 Sides 5th 30 Sides Carcass Groups / Time 04/04/ /04/ /04/ /04/ /04/ /04/2005 Fig. 5. Illustrates the response to contamination over production time in the Wrst six days of observation. Carcass Contamination - Time Trend Day 7 to 11 Carcasses Contaminated st 30 Sides 2nd 30 Sides 3rd 30 Sides 4th 30 Sides 5th 30 Sides 25/04/ /04/ /06/ /06/ /06/2005 Carcass Groups / Time Fig. 6. Illustrates the response to contamination over production time in the last Wve days of observation. 4. Conclusions The benewts to be derived from an on-line monitoring and display system towards enhancing food safety within a beef slaughtering plant have being adequately demonstrated by this study. The information obtained from using such an intervention system on a daily basis greatly assisted in making profound attitudinal and behavioural changes amongst both process operatives and supervisory management resulting in signiwcant reductions in visible carcass contamination. The cost of installing the on-line monitoring and display system was relatively modest and required minimal resources. References Bell, R. G. (1997). Distribution and sources of microbial contamination on beef carcasses. Journal of Applied Microbiology, 82, Bolton, D. J., Doherty, A. M., & Sheridan, J. J. (2001). Beef HACCP: Intervention and non-intervention systems. International Journal of Food Microbiology, 66, Bolton, D. J., Oser, A. H., Cocoma, G. J., Palumbo, S. A., & Miller, A. (1999). Integrating HACCP and TQM reduces pork carcass contamination. Food Technology, 53, Bruce, M. E., Will, R. G., Ironside, J. W., McConnell, I., Drummond, D., Suttie, A., et al. (1997). Transmissions to mice indicate that new variant CJD is caused by the BSE agent. Nature, 389, Collinge, A., Sidle, L. M., Goodson, K. J., Savell, J. W., & AcuV, G. R. (1996). Molecular analysis of prion strain variation and the aetiology of new variant CJD. Nature, 383, Gill, C. O., & Bryant, J. (1997). Decontamination of carcasses by vacuum hot water cleaning and steam pasteurizing during routine operations at a beef packing plant. Meat Science, 47, Gill, C. O., Bryant, J., & Bedard, D. (1999). The evects of hot water pasteurizing treatments on the appearances and microbiological conditions of beef carcass sides. Food Microbiology, 16, Gill, C. O., & Mc Ginnis, J. C. (1999). Improvements of the hygiene performance of the hindquarters skinning operations at a beef packaging plant. International Journal of Food Microbiology, 5, Gill, C. O., Mc Ginnis, J. C., & Baldoni, M. (1995a). Assessment of the hygienic characteristics of a beef carcass dressing process. Journal of Food Protection, 59, Gill, C. O., Mc Ginnis, J. C., & Baldoni, M. (1995b). Hygienic evects of trimming and washing operations in a beef carcass dressing process. Journal of Food Protection, 59, Hudson, W. R., Mead, G. C., & Hinton, M. H. (1996). Relevance of abattoir hygiene assessment to microbiological contamination of British beef carcasses. Veterinary Record, 139, Jericho, W. F., Bradley, J. A., Gannon, P. J., & Kozub, G. C. (1992). Visual demerit and microbiological evaluation of beef carcasses: Methodology. Journal of Food Protection, 5(2),

8 696 J.H. Ryan / Food Control 18 (2007) Le Jeune, J. T., & Christie, N. P. (2004). Microbiological quality of ground beef from conventionally reared cattle and Raised without Antibiotics label claims. Journal of Food Protection, 67(7), Nutsch, A. L., Randall, K., Phebus, R. K., Riemann, M. J., Kotrola, J. S., Craig Wilson, R., et al. (1998). Steam pasteurisation of commercially slaughtered beef carcasses: evaluation of bacterial populations at Wve anatomical locations. Journal of Food Protection, 61, Schnell, T. D., Sofos, J. N., LittleWeld, V. G., Morgan, J. B., Gorman, B. M., Clayton, R. P., et al. (1995). EVects of postexsanguination dehairing on the microbial load and visual cleanliness of beef carcasses. Journal of Food Protection, 58, Sheridan, J. J. (1998). Sources of contamination during slaughter and measures for control. In J. J. Sheridan, M. O KeeVe, & M. Rogers (Eds.), Food safety implications of change from producerism to consumerism (pp ). USA: Food and Nutrition Press, Inc. Smulders, F. J. M., & Greer, G. G. (1998). Integrating microbial decontamination with organic acids in HACCP programmes for muscle foods: prospects and controversies. International Journal of Food Microbiology, 44, Tergney, A., & Bolton, D. J. (2005). Validation studies on an online monitoring system for reducing faecal and microbiological contamination on beef carcases. Food Control.