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ANNUAL CONFERENCE :: Abstract Library
Abstract Library
2003 Conference Abstract
| Type of Submission |
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Submission Type: |
Poster Presentation |
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Subject Category: |
Veterinary Microbiology |
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| Session Information |
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Presentation Date: |
May 26, 2003 |
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Abstract ID: |
G12 |
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Session: |
Poster 1 |
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Time: |
14:00 |
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| Presenting Author |
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| Other Authors |
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S. MESSIER, Faculty of Veterinary Medicine (GREMIP)
L. SAUCIER, Food Research and Development Centre
G. PIETTE, Food Research and Development Centre
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| Title |
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Influence of inoculum preparation, inoculation procedure and process parameters on Escherichia coli O157: H7 survival during the validation of sausage fermentation-drying processes |
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| Abstract Text |
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The influence of inoculum preparation, inoculation level, and inoculation procedure on Escherichia coli O157:H7 inactivation during the validation of fermentation-drying processes was evaluated. Initial growth in glucose-enriched TSB medium, which provided exposure to mildly acidic conditions (pH 4.8), had no effect on the later survival of E. coli O157:H7 strains 5-1, 387-2, and ATCC 43894 in extremely acidic conditions (pH 2), but the same strains became sensitive to acidity after a 7 day incubation on the surface of refrigerated beef (as per the normal contamination route from slaughter to further processing). In subsequent sausage production trials, the extent of destruction observed for E. coli O157:H7 strains F-90, 5-1, and ATCC 43894, inoculated directly in the meat batter stage, was unchanged when inoculation level was decreased from 7.3 to 4.7 log10 CFU/g, but inactivation was ca. 1 log10 higher when inoculation was done at the surface of beef cuts 7 days prior to processing, rather than in the batter. Regardless of processing conditions (fermentation to pH ≤5.3 at 24°C or 37°C, drying at 13°C to aw 0.90 or 0.80), strains F-90, 5-1, and ATCC 43894 showed a similar survival capacity during sausage manufacture. A < 2 log10 reduction in pathogen numbers was generally obtained after drying to aw 0.90, irrespective of fermentation temperature. The addition of a 7 day pre-drying holding step at fermentation temperature significantly increased (P <0.05) pathogen inactivation when fermenting at 37°C (but not at 24°C). However, the most important pathogen reduction (4-5 log10 CFU/g) was generally achieved by extending drying to reach aw 0.80. |
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