GROWTH AND SURVIVAL OF Listeria monocytogenes IN CHICKEN GRAVY DURING COOLING AND REFRIGERATED STORAGE

Autor: I-Ping D. Huang, Elmer H. Marth, M. Eileen Matthews, Ahmed E. Yousef
Rok vydání: 1993
Předmět:
Zdroj: Foodservice Research International. 7:185-192
ISSN: 1745-4506
1524-8275
DOI: 10.1111/j.1745-4506.1993.tb00217.x
Popis: Survival of Listeria monocytogenes in chicken gravy during processing by the cook-chill method was studied because this pathogen is of major concern in the safety of refrigerated foods in foodservices. Cooked gravy (70 to 77C) was poured into 1.9, 3.8 or 5.7L. pans and refrigerated at 7C. When cooled to 40C, gravy was inoculated with L. monocytogenes strain Scott A to give ca. 104 CFU/ml. Samples (59.1 ml) were taken every 6 h. during the first 24 h, then once a day for the subsequent 11 days and numbers of L. monocytogenes were determined. Time required to cool 1.9, 3.8 and 5.7 L. of gravy from 70–77C to 7C averaged 12, 20 and 26 h, respectively. Populations of L. monocytogenes ranged from 1.0 × 105 to 3.2 × 106 CFU/ml after 24 h of refrigeration and growth rates in different volumes of gravy were significantly (P < .001) different. Maximum growth (≥ 108 CFU/ml) of L. monocytogenes was reached 4 to 6 days after inoculation, depending on the volume of gravy. The population remained at 108–109 CFU/ml during the rest of chilled storage. There was no decrease in populations of L. monocytogenes even after extended refrigerated storage of the gravy. Hazardous conditions can occur easily if cooling and storage conditions in an actual foodservice operation are similar to those used in this study.
Databáze: OpenAIRE
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