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Pathogen survival in chorizos: ecological factors
Carrie M Hew1, Maha N Hajmeer, Thomas B Farver
1Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, California 95616, USA.
Journal of Food Protection
|May 24, 2006
Summary
Small-scale ethnic sausages pose health risks due to pathogen survival. Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella showed insufficient death rates in Mexican-style chorizo, even with controlled pH and water activity (a(w)).
Area of Science:
- Food Microbiology
- Food Safety
- Sausage Production
Background:
- Small-scale ethnic sausages, like Mexican-style chorizo, often lack inspection, posing potential health risks.
- Raw pork sausages are susceptible to contamination by foodborne pathogens such as Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella.
- Understanding pathogen survival under various processing and storage conditions is crucial for ensuring food safety.
Purpose of the Study:
- To assess the health risks associated with the production of ethnic sausages.
- To evaluate the survival rates of key foodborne pathogens (E. coli O157:H7, L. monocytogenes, Salmonella) in Mexican-style chorizo under controlled conditions.
- To determine the impact of physical parameters (pH, water activity) and ingredients (spices) on pathogen reduction.
Main Methods:
- Experimental contamination of Mexican-style chorizo batter with E. coli O157:H7, L. monocytogenes, and Salmonella.
- Controlled adjustment of pH (using vinegar) and water activity (a(w)) (using salt).
- Monitoring pathogen survival over 7 days of storage at various temperatures and pH levels, alongside analysis of spice microflora and antimicrobial effects.
Main Results:
- Pathogen numbers generally declined during storage, but death rates were not rapid enough for safety.
- Higher water activity (a(w)) levels correlated with increased death rates for E. coli O157:H7 and Salmonella compared to L. monocytogenes.
- Some spices, like black pepper and cumin, harbored indigenous microflora, increasing the initial microbial load, while only garlic showed a significant antimicrobial effect.
Conclusions:
- Current formulations and processing of Mexican-style chorizo, even with controlled parameters, do not ensure rapid pathogen inactivation.
- Further strategies are needed to enhance the safety of small-scale ethnic sausages against foodborne pathogens.
- The study highlights the need for improved safety protocols in the production of minimally processed meat products.