Pathogen survival in chorizos: Ecological factors

Carrie M. Hew, Maha N. Hajmeer, Thomas B Farver, Hans P. Riemann, James M. Glover, Dean O. Cliver

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


This study addressed health risks from ethnic sausages produced on a small scale, without inspection, in California and elsewhere. Mexican-style chorizo, a raw pork sausage that is not cured, fermented, or smoked, was contaminated experimentally in the batter with Escherichia coli O157:H7, Listeria monocytogenes, or Salmonella serotypes and stuffed into natural casings. Formulations were based on a market survey in California. Physical parameters that were controlled were pH, water activity (aw), and storage temperature. The pH was adjusted with vinegar, stabilizing at 5.0 within 24 h. Initial aw levels adjusted with salt were 0.97, 0.95, 0.93, 0.90, and 0.85; levels declined with time because of evaporation. Pathogen numbers declined with storage up to 7 days, with few brief exceptions. Main effects and interactions of constant temperature and pH with declining aw on survival of the pathogens were determined. Maximum death rates occurred at higher aw for E. coli O157:H7 and Salmonella than for L. monocytogenes. Salt used to adjust aw affected palatability. Spices (black pepper, chili pepper, chili powder, cumin, garlic, guajillo pepper, oregano, and paprika) comprised another, potentially significant aspect of the sausage formulation. Some (notably black pepper and cumin) carried an indigenous microflora that contributed significantly to the microbial load of the sausage batter. Only undiluted fresh and powdered garlic exhibited a significant antimicrobial effect on the pathogens. Although each of the tested formulations caused death of the inoculated pathogens, none of the death rates was sufficiently rapid to ensure safety within the probable shelf life of the product.

Original languageEnglish (US)
Pages (from-to)1087-1095
Number of pages9
JournalJournal of Food Protection
Issue number5
StatePublished - May 2006

ASJC Scopus subject areas

  • Food Science
  • Applied Microbiology and Biotechnology
  • Biotechnology
  • Microbiology


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