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Published on: October 11, 2018
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Thermal Inactivation of Clostridium perfringens Enterotoxin
1Food Research Institute and Department of Food Microbiology and Toxicology University of Wisconsin, Madison, Wisconsin 53706.
Journal of Food Protection
|February 24, 2019
Summary
Clostridium perfringens enterotoxin lost biological activity within 5 minutes at 60°C. However, residual serological activity persisted longer, especially in neutral or alkaline conditions, and could be partially recovered in food matrices.
Area of Science:
- Food Microbiology
- Food Safety
- Bacterial Toxinology
Background:
- Clostridium perfringens is a foodborne pathogen that produces enterotoxin.
- Understanding the thermal stability of this enterotoxin is crucial for food safety.
- Previous studies have focused on biological activity, but serological activity requires further investigation.
Purpose of the Study:
- To investigate the thermal inactivation kinetics of Clostridium perfringens enterotoxin.
- To assess the impact of pH and food matrices on enterotoxin stability.
- To determine if heat-inactivated serological activity can be recovered.
Main Methods:
- Thermal inactivation assays at 60°C in saline, buffers (pH 5.4-8.0), and food matrices (cooked turkey, gravies, protein solutions).
- Monitoring of biological and serological activity loss over time.
- Flocculation tests to assess toxin aggregation.
- Urea treatment to evaluate recovery of serological activity.
Main Results:
- Biological activity was destroyed within 5 minutes at 60°C.
- Significant residual serological activity remained after 80 minutes at 60°C, particularly at neutral to alkaline pH.
- Loss of serological activity was faster at acidic pH (5.4-6.0) compared to neutral/alkaline pH (7.0-8.0).
- Flocculation occurred at acidic pH but not at neutral/alkaline pH.
- Rapid loss of serological activity was observed in food matrices and protein solutions.
- Up to 12% of heat-inactivated serological activity was recoverable with urea treatment in food samples, but not in buffer.
Conclusions:
- Clostridium perfringens enterotoxin exhibits differential thermal inactivation between biological and serological activity.
- pH significantly influences the thermal stability and aggregation of the enterotoxin.
- Food matrices can affect enterotoxin stability, with partial recovery of serological activity possible.
- These findings have implications for assessing the safety of heat-treated foods potentially contaminated with C. perfringens.
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