The combined effect of starter culture (107 CPU of lactic acid bacteria per ml), dextrose (0.8%), sodium chloride (2%), nitrite (200 ppm), and temperature (37 and 22°C) on survival of bioluminescent Escherichia coli O157:H7 (l00 to 105 CPU/ml)
in brain heart infusion (BHI) broth was determined. Two model systems representing fermented sausage production were evaluated. The first was the "American style" employing high-temperature (37°C) and short-time (1-day) fermentation. The second was the "European style" in which 22°C
was used for 3 days. After fermentation, the samples were stored at 10°C and the survival of E. coli O157:H7 was monitored over an extended period of time. In the "American style" model, E. coli O157:H7 survived a more than 34-day period in BHI containing starter culture
and dextrose, while it survived for a more than 51-day period in BHI containing starter culture, dextrose, sodium chloride, and nitrite. In the "European style" model, the survival time of E. coli O157:H7 during fermentation was longer in BHI containing starter culture and dextrose
than in BHI containing starter culture, dextrose, sodium chloride, and nitrite. E. coli O157:H7 did not survive past 9 days in BHI containing starter culture and dextrose. Similarly, in BHI containing starter culture, dextrose, sodium chloride, and nitrite the lower E. coli O157:H7
inoculations (l00 to 104 CPU/ml) did not survive past 9 days; however, at higher inoculum levels (≥105 CPU/ml) the organism survived more than 30 days. In conclusion, the lower temperature and longer fermentation time ("European style") is better for elimination
of E. coli O157:H7 from a model system representing a fermented sausage production than fermentation at high temperature and short time ("American style").
Department of Food Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1
Publication date: December 1, 1997
More about this publication?
IAFP Members with personal subscriptions to JFP Online: To access full-text JFP or JMFT articles, you must sign-in in the upper-right corner using your Ingenta sign-in details (your IAFP Member Login does not apply to this website). The Journal of Food Protection (JFP) is a refereed monthly publication. Each issue contains scientific research and authoritative review articles reporting on a variety of topics in food science pertaining to food safety and quality. The Journal is internationally recognized as the leading publication in the field of food microbiology with a readership exceeding 11,000 scientists from 70 countries. The Journal of Food Protection is indexed in Index Medicus, Current Contents, BIOSIS, PubMed, Medline, and many others.
Print and online subscriptions are available to IAFP Members and institutional subscribers. IAFP Members with a subscription to JFP Online will have access to all available JFP and JMFT content. Online visitors who are not IAFP Members or journal subscribers will be charged on a pay-per-view basis. Membership and subscription information is available at www.foodprotection.org.