# Presentation: 346615

## PATHOGEN REDUCTION                      A SCIENTIFIC DIALOGUE 

**PATHOGEN REDUCTION                      A SCIENTIFIC DIALOGUE**** **
**PANEL 4: INTERVENTION STRATEGIES**
**REDUCTION OF CONTAMINATION AT SLAUGHTER**

- John N. Sofos
- May 7, 2002

## Reduction of Contamination at Slaughter

**Reduction of Contamination at Slaughter**

- Decontamination Processes or Interventions
-  Before hide removal
-  Animal cleaning and hair removal
-  Chemical dehairing
-  After hide removal
-  Knife-trimming or Steam-vacuuming
-  Washing/Spraying/Rinsing
-  Water or Chemicals; Cold or Hot
-  Pressurized steam
-  Chilling
-  Multiple Combined/Sequential Interventions
-  Fabrication/Distribution/Processing/Retail?

## Reduction of Contamination at Slaughter

**Reduction of Contamination at Slaughter**

**ANIMAL CLEANING**
**AND**
**HAIR REMOVAL **

## Reduction of Contamination at Slaughter

**Reduction of Contamination at Slaughter**

-  Animal cleaning and hair removal
-  Fecal tag and hair removal
-  Animal washing
-  Variable results
-  Limited application
-  Climate/facilities
-  Alternatives:
-  Segregate soiled animals
-  Reduce slaughter speed
-  Increase personnel

## Reduction of Contamination at Slaughter

**Reduction of Contamination at Slaughter**

**CHEMICAL DEHAIRING**

## Reduction of Contamination at Slaughter

**Reduction of Contamination at Slaughter**

-  Chemical dehairing
-  Effective procedure
-  Sodium sulfide and hydrogen peroxide
-  Spraying
-  Capital investment
-  Waste handling
-  Sodium sulfide: regeneration and reuse
-  Hydrolyzed hair: fertilizer

## Reduction of Contamination at Slaughter

**Reduction of Contamination at Slaughter**

**KNIFE-TRIMMING                        **
**AND                                             **
**STEAM-VACUUMING**

## Reduction of Contamination at Slaughter

**Reduction of Contamination at Slaughter**

-  Knife-Trimming
-  Required “Zero Tolerance”
-  Variable results for microbial reduction
-  Potential for spreading and cross-contamination
-  Necessary and important for aesthetics
-  Steam-vacuuming
-  Spot decontamination (1 inch)
-  Variable results
-  Equipment maintenance
-  Employee diligence

## Reduction of Contamination at Slaughter

**Reduction of Contamination at Slaughter**

**CARCASS WASHING                      **
**AND                     **
**DECONTAMINATION**

## Reduction of Contamination at Slaughter

**Reduction of Contamination at Slaughter**

-  Whole (pre-evis) or half (before chilling) carcass
-  Immersion/flooding/deluging/cascading
-  Spraying or rinsing
-  Water or chemical solutions
-  Important variables:
-  Method, stage and time of application
-  Equipment design and maintenance
-  Pressure and nozzle type
-  Temperature
-  Chemicals
-  Duration

## Reduction of Contamination at Slaughter

**Reduction of Contamination at Slaughter**

-  Carcass decontamination before evisceration
-  Spraying/Rinsing
-  Prevention of attachment
-  Organic acid solutions
-  Spraying pressure limitations
-  Weight gain concerns
-  Water temperature limitations
-  Condensation problems

## Reduction of Contamination at Slaughter

**Reduction of Contamination at Slaughter**

-  Final carcass water washing
-  Thermal decontamination
-  Hot water (>74oC)
-  Pressurized steam
-  Chemical decontamination
-  Spraying/Rinsing
-  Organic acids (1.5-2.5%)
-  Acetic
-  Lactic
-  Warm (55oC)

## Reduction of Contamination at Slaughter

**Reduction of Contamination at Slaughter**

-  Chemical decontamination
-  Chlorine/Chlorine dioxide (20-50 ppm)
-  Trisodium phosphate (8-12%)
-  Ozone
-  Acidified sodium chlorite
-  Peroxyacetic acid-based
-  Activated lactoferrin
-  Cetylpyridinium chloride
-  Acidified calcium sulfate
-  Hydrogen peroxide

## Reduction of Contamination at Slaughter

**Reduction of Contamination at Slaughter**

-  Other chemical decontaminants after carcass washing:
-  Sodium chloride
-  Sodium hydroxide
-  Nisin
-  Potassium sorbate
-  Sodium bisulfate
-  Other decontamination processes after carcass washing:
-  Ionizing radiation
-  UV radiation
-  Microwaves
-  Pulsed light
-  Electric fields
-  Hydrostatic pressure
-  Sonication

## Reduction of Contamination at Slaughter 

**Reduction of Contamination at Slaughter **

**MULTIPLE                          **
**COMBINED AND/OR SEQUENTIAL **
**DECONTAMINATION**

## Reduction of Contamination at Slaughter

**Reduction of Contamination at Slaughter**

-  Decontamination with multiple interventions
-  Combinations of treatments:
-  Warm acid solutions
-  Steam and vacuum
-  Sequential application of:
-  Animal cleaning
-  Chemical dehairing
-  Knife-trimming
-  Steam-vacuuming
-  Pre-evisceration washing
-  Final carcass washing
-  Chemical and/or thermal decontamination
-  Carcass chilling

## Reduction of Contamination at Slaughter 

- Commercial Beef Carcass Decontamination in 6 Plants

**	****	****Positive/Tested**
**Treatments****	****	*****Listeria******	******Salmonella******	******E.coli***** ****	****	****	****	****	****	****	****	****O157:H7**
- Control		62/142	43/142	1/142
- Trimmed (T)	35/140	11/142	3/142
- Washed (W)	39/143	13/144	1/144
- T + W		18/143	 2/144	2/144
*Reagan et al. (1996)*

## Reduction of Contamination at Slaughter

**Reduction of Contamination at Slaughter**

**CARCASS WASHING                      **
**AND                     **
**DECONTAMINATION             **
**CONCERNS**

## Reduction of Contamination at Slaughter

**Reduction of Contamination at Slaughter**

-  Concerns associated with decontamination 	processes
-  Variability: plant, animal lot, method, animal 	type, season, anatomical site, plant site, 	method of sampling
-  Spreading or redistribution of bacteria
-  Penetration
-  Attachment/Biofilms
-  Removal vs. Inactivation vs. Injury
-  Selection/resistance/adaptation

## Reduction of Contamination at Slaughter

**Reduction of Contamination at Slaughter**
***Salmonella***** in 4 Steer/Heifer and 3 Cow/Bull Plants**
**Animal Type and Season Variation**

## Reduction of Contamination at Slaughter   Animal lot and plant variation in carcass contamination with    E. coli O157:H7 (Percent positive) Elder et al. (2000)

**Plant****	****Lot****	****Fecal****	****Hide****	****Pre-evis****	****Post-evis****	****Washed**
-     A	    1/1	     77	     11	     56		     17		      0
- 	    1/2 	      0	      0	     75		      0		      0
- 	    1/3	      13	      6	     56		      0	                  0
- 	    2/1	      22	      0	       0		      0		      0
-     B	     1/1	        0	      0	       0		      0		      0
- 	     1/2	        0	      0	      11		      0		      0
- 	     1/3	      10	      0	     60		    38		      0
- 	     2/1	      44	    78	     89		    78		    22
-     C	     1/3	      30	      0	     80		    60		      0
-     D	     1/1	        0	      0	     38		      0		      0

## Reduction of Contamination at Slaughter

**Reduction of Contamination at Slaughter**

-  Decontamination intervention concerns
-  Safety of application
-  Toxicology
-  Worker health
-  Product safety
-  Product quality
-  Appearance
-  Taste
-  shelf-life
-  Functionality
-  Environmental concerns
-  Waste/Pollution
-  Equipment

## Reduction of Contamination at Slaughter

**Reduction of Contamination at Slaughter**

**RECONTAMINATION CONCERNS **
**AND POTENTIAL FOR **
**POST-SLAUGHTER DECONTAMINATION**

## Reduction of Contamination at Slaughter

**Reduction of Contamination at Slaughter**

-  Contamination concerns following slaughter
-  Carcass chilling
-  Contamination reduction?
-  Microbial growth?
-  Additional contamination?
-  Chilling rate
-  Chilling uniformity
-  Sanitation and hygiene

## Reduction of Contamination at Slaughter

**Reduction of Contamination at Slaughter**

-  Carcass fabrication concerns
-  New and additional contamination
-  Spreading and redistribution
-  Microbial growth
-  Sanitation and hygiene
-  Room temperature
-  Time duration
-  Potential decontamination interventions
-  Application technology issues
-  Labeling issues

## Mean TPC On Carcasses, Belts & Subprimals As Processing Time Progressed

**Log CFU/100 cm****2**

**Time Of Day**

*Bacon et al. (2002)*

## Acid-adapted Listeria monocytogenes in vacuum packaged beef Not-treated:    , Water (55°C):   , Water (75°C):   , Lactic acid (55°C):     , Acetic acid (55°C):      

- 2

*d*

*b*

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*c*

*a*

*d*

*d*

*c*

*a*

*b*

*c*

*c*

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*a*

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*b*

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*a*

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*(Ikeda et al., 2001)*

## Reduction of Contamination at Slaughter

**Reduction of Contamination at Slaughter**

**QUESTIONS**
**CONCERNS**
**ISSUES**

## Reduction of Contamination at Slaughter   Questions/Concerns/Issues

**Reduction of Contamination at Slaughter   ****Questions/Concerns/Issues**

-  Spreading of contamination and cross-contamination
-  Animal lot and plant variation
-  Extent of carcass and product area contaminated
-   Prevalence vs population reductions by decontamination
-  Transfer of contamination from carcasses to meat
-  Fabrication contamination concerns and interventions
-  Instantaneous or short intensity interventions
-  Intensity inadequate for complete inactivation
-  Alteration of metabolic activity of survivors?
-  Changes in plant and meat microbial association
-  Selection/Adaptation/Cross-protection/Virulence?*	**	**	**	**	**	*

## Reduction of Contamination at Slaughter

**Reduction of Contamination at Slaughter**

**SUMMARY**

-  Decontamination interventions are useful:
-  Reduce carcass contamination (1-3 logs)
-  Reduce pathogen prevalence
-  Assist plants meet regulatory/industry criteria
-  However, they should be:
-  Evaluated for potential unpredictable risks
-  Optimized for maximum benefits with no risks
-  Consider potential long term effects of interacting sublethal interventions on the microbial ecology of plants and raw and ready-to-eat products

## Reduction of Contamination at Slaughter

**Reduction of Contamination at Slaughter**

**SUMMARY**

-  Select and apply proper interventions of the right intensity and in the correct sequence in order to maximize antimicrobial effects and minimize resistance development
-  Evaluate further processing concerns
-  Research new technologies and beyond slaughter
-  Validation of decontamination technologies
-  Minimize decontamination variations
-  Not ready-to-eat until further processed/cooked
-  Useful in reducing probability of illness when product intentionally or unintentionally undercooked