Survival of Enteropathogenic and Non-Pathogenic Escherichia coli During the Manufacture of Camembert Cheese
Autor: | Elmer H. Marth, N. F. Olson, J. F. Frank |
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Rok vydání: | 2019 |
Předmět: |
food.ingredient
food and beverages Ripening Biology medicine.disease_cause biology.organism_classification Camembert cheese Microbiology chemistry.chemical_compound food chemistry Most probable number Pathogenic Escherichia coli medicine Agar Trypticase soy agar Food science Escherichia coli Food Science |
Zdroj: | Journal of food protection. 40(12) |
ISSN: | 1944-9097 |
Popis: | Camembert cheese was manufactured from milk contaminated with pathogenic and nonpathogenic strains of Escherichia coli . E. coli was enumerated using Violet Red Bile Agar (VRB) pour plates, a most probable number method, and surface plating on Trypticase Soy Agar (TSA) plates followed by an overlay of VRB (TSA + VRB). Numbers of E. coli during cheese manufacture increased about two log cycles during the first 6 h, then decreased during the initial stages of ripening with some strains disappearing from the cheese within the first 2 weeks of ripening, and other strains surviving 4 to 6 weeks. The rate of inactivation of E. coli in the cheese decreased as the cheese ripened and the pH increased. No growth of E. coli was observed in ripe cheese at a pH of 6.7, however rapid growth of E. coli occurred on the surface of the cheese. The TSA + VRB method was acceptable for enumeration of E. coli in Camembert cheese. |
Databáze: | OpenAIRE |
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