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Decontaminating beef for Escherichia coli O157:H7
I Delazari1, S T Iaria, H P Riemann
1Sadia Concordia S. A. Com. Ind., Garantia da Qualidade, São Paulo, Brazil.
Journal of Food Protection
|August 26, 1998
Summary
Prewashing beef tissues with water reduced Escherichia coli O157:H7, but hindered disinfectant effectiveness. Specific disinfectants like chlorhexidine and hydrogen peroxide showed varying efficacy depending on the beef tissue type.
Area of Science:
- Food Microbiology
- Food Safety
- Bacterial Contamination Control
Background:
- Escherichia coli O157:H7 is a significant foodborne pathogen.
- Contamination of beef products poses a public health risk.
- Effective decontamination strategies for beef tissues are crucial for food safety.
Purpose of the Study:
- To evaluate the impact of prewashing on bacterial adherence and removal from beef tissues.
- To compare the efficacy of different disinfectant solutions for eliminating Escherichia coli O157:H7.
- To determine the influence of beef tissue type (lean, fat, connective) on decontamination effectiveness.
Main Methods:
- Beef tissues (lean, fat, connective) were inoculated with Escherichia coli O157:H7.
- A prewashing step using tap water was applied before or after inoculation.
- Final washing involved various disinfectant solutions (hydrogen peroxide, chlorhexidine, acetic acid) or water.
- Bacterial reduction was quantified using colony-forming units (CFU) per square centimeter.
Main Results:
- Prewashing significantly reduced bacterial numbers on lean tissue when followed by water washing.
- Prewashing decreased disinfectant efficacy, potentially due to water dilution.
- Hydrogen peroxide (3%) was highly effective on connective tissue (>4 log CFU/cm2 reduction).
- Chlorhexidine (0.1%) demonstrated superior efficacy on fat and lean tissues (>5 log CFU/cm2 reduction on non-prewashed samples).
- Acetic acid (5%) showed minimal effectiveness across all tissue types.
Conclusions:
- Prewashing can reduce bacterial load but may interfere with subsequent chemical decontamination.
- Disinfectant efficacy is tissue-dependent, with chlorhexidine and hydrogen peroxide showing promise.
- Optimizing decontamination protocols requires considering both pre-treatment and disinfectant choice for specific beef tissues.