|Title of Research:
Application of Novel Hurdle Technologies
to Meat Carcass Trimmings for Reduction of Pathogens
Texas A&M University, College Station, Texas; University of
Arkansas; USDA-ARS, College Station, Texas.
Drs. Jimmy T. Keeton, Steve Ricke, Robin Anderson, Douglas
Miller, and Njongmeta Nenge Lynda Azefor.
Overall objective: Evaluate undeveloped and cost effective pathogen interventions using a multiple hurdle
approach suitable for small meat plant operations in an effort to further reduce contamination and
growth of pathogens, specifically Salmonella spp., E.coli O157:H7 , and Listeria monocytogenes.
- Evaluate warm water (control), lactic acid, acidified calcium sulfate (ACS) and/or epsilon-polylysine (EPL) as beef carcasses/trimmings decontamination agents using minimal application procedures to reduce the time and cost of the intervention for small plants that are applied as a warm rinse following standard washing procedures. Different concentrations of the treatments were examined to determine optimal reduction of Salmonella Typhimurium (ST),
E. coli O157:H7 (EC), and Listeria monocytogenes (LM).
- Determine the residual antimicrobial effects of ACS with and without EPL over time on carcasses/trimmings and selected raw products.
- Evaluate the efficacy of the best intervention identified above in two to three small local processing plants and to determine its efficacy as part of the HACCP plan.
- Evaluate the bactericidal/bacteriostatic efficacy of the best treatment on a cooked ready-to-eat (RTE) product contaminated with a
Listeria cocktail. Due to time limitations, this objective was not covered, but it merits further study.
A hot (55°C) spray application of ACS followed sequentially by
a hot EPL spray at constant pressure for 15-20 seconds
reduced ST, EC, and LM inoculated on the skin-side surface
of pre-rigor beef rounds more effectively than a single
treatment of ACS, LA, EPL, or warm water alone. A 5 to 10
minute interval was allowed between ACS and EPL applications
to simulate carcass processing in a small plant which would
not have continuous line speeds as found in high capacity
operations. In general, all decontamination treatments,
except warm water alone, caused a reduction in ST counts
after 7 days of refrigerated storage with the ACS + EPL
combination being the most effective antimicrobial treatment
against ST. EPL appears to have enhanced antimicrobial
activity in combination with acidic antimicrobials. The ACS
+EPL combination was the most effective antimicrobial
treatment against EC while warm water showed the least
reduction. The greatest mean log reductions in ST, EC, and
LM on pre-rigor beef rounds were obtained when ACS was
applied followed immediately (within 5-10 minutes) by EPL.
The results of this study support the use of multiple
interventions as a better strategy for pathogen reduction in
small processing plants more so than single treatments. It
also appears that the combination of antimicrobial agents
that express different modes of action for suppressing
pathogen growth and the sequential application of different
decontamination sprays (e.g., ACS + EPL) are significant
factors for obtaining greater reductions in pathogen numbers
on beef carcasses at slaughter. This research should also
help minimize their operating cost while helping them to
ensure food safety and public health protection. Plants
will, however, need to validate that their methodology
achieves these parameters.
The full report on this research can be found on the Fiscal Year 2004 table under the column Food Safety Technologies - Additional Information.