Growth of Listeria monocytogenes in skim, whole and chocolate milk, and in whipping cream during incubation at 4, 8, 13, 21 and 35 grade centigrade

Autoclaved samples of skim, whole, and chocolate milk and of whipping cream were inoculated with Listeria monocytogenes (one to four strains were tested individually, depending on the experiment) and incubated at 4, 8, 13, 21 or 35 grade centigrade. Growth curves were then derived and generation times and maximum populations calculated for each combination of strain, product, and temperature. The growth rate of L. monocytogenes was similar in all four products at a given incubation temperature and increased with an increase in temperature. Doubling times over all products and strains were 41 min (35 grade centigrade), 1 h 43 min-1 h 55 min (21 grade centigrade), 4 h 27 min-6 h 55 min (13 grade centigrade), 8 h 40 min-14 h 33 min (8 grade centigrade), and 29 h 44 min-45 h 33 min (4 grade centigrade). In each instance, maximum populations reached were at least 10 exponent 7 cells/ml, with highest numbers consistently produced in chocolate milk (at least 10 times greater than in skim or whole milk or cream at any temperature). Little decrease in final numbers occurred with extended storage at the incubation temperature being studied. All results were analyzed statistically to determine magnitude and source of variation. Observed differences in data resulted from interactive effects between strain, product, and temperature. Therefore, no single factor can be considered as the sole cause of a particular finding. That L. monocytogenes can attain such high populations at low temperatures should be of concern. Since refrigerated storage is no guarantee of protection against growth of L. monocytogenes, every precaution should be taken to prevent contamination of certain foods by this organism.

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Main Authors: 113471 Rosenow, E.M., 90661 Marth, E.H.
Format: biblioteca
Published: Jun
Subjects:CHOCOLATE, LISTERIA MONOCYTOGENES, BACTERIA, POLUCION, INOCULACION,
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spelling KOHA-OAI-BVE:712282020-02-03T21:38:18ZGrowth of Listeria monocytogenes in skim, whole and chocolate milk, and in whipping cream during incubation at 4, 8, 13, 21 and 35 grade centigrade 113471 Rosenow, E.M. 90661 Marth, E.H. Jun 1987Autoclaved samples of skim, whole, and chocolate milk and of whipping cream were inoculated with Listeria monocytogenes (one to four strains were tested individually, depending on the experiment) and incubated at 4, 8, 13, 21 or 35 grade centigrade. Growth curves were then derived and generation times and maximum populations calculated for each combination of strain, product, and temperature. The growth rate of L. monocytogenes was similar in all four products at a given incubation temperature and increased with an increase in temperature. Doubling times over all products and strains were 41 min (35 grade centigrade), 1 h 43 min-1 h 55 min (21 grade centigrade), 4 h 27 min-6 h 55 min (13 grade centigrade), 8 h 40 min-14 h 33 min (8 grade centigrade), and 29 h 44 min-45 h 33 min (4 grade centigrade). In each instance, maximum populations reached were at least 10 exponent 7 cells/ml, with highest numbers consistently produced in chocolate milk (at least 10 times greater than in skim or whole milk or cream at any temperature). Little decrease in final numbers occurred with extended storage at the incubation temperature being studied. All results were analyzed statistically to determine magnitude and source of variation. Observed differences in data resulted from interactive effects between strain, product, and temperature. Therefore, no single factor can be considered as the sole cause of a particular finding. That L. monocytogenes can attain such high populations at low temperatures should be of concern. Since refrigerated storage is no guarantee of protection against growth of L. monocytogenes, every precaution should be taken to prevent contamination of certain foods by this organism.Autoclaved samples of skim, whole, and chocolate milk and of whipping cream were inoculated with Listeria monocytogenes (one to four strains were tested individually, depending on the experiment) and incubated at 4, 8, 13, 21 or 35 grade centigrade. Growth curves were then derived and generation times and maximum populations calculated for each combination of strain, product, and temperature. The growth rate of L. monocytogenes was similar in all four products at a given incubation temperature and increased with an increase in temperature. Doubling times over all products and strains were 41 min (35 grade centigrade), 1 h 43 min-1 h 55 min (21 grade centigrade), 4 h 27 min-6 h 55 min (13 grade centigrade), 8 h 40 min-14 h 33 min (8 grade centigrade), and 29 h 44 min-45 h 33 min (4 grade centigrade). In each instance, maximum populations reached were at least 10 exponent 7 cells/ml, with highest numbers consistently produced in chocolate milk (at least 10 times greater than in skim or whole milk or cream at any temperature). Little decrease in final numbers occurred with extended storage at the incubation temperature being studied. All results were analyzed statistically to determine magnitude and source of variation. Observed differences in data resulted from interactive effects between strain, product, and temperature. Therefore, no single factor can be considered as the sole cause of a particular finding. That L. monocytogenes can attain such high populations at low temperatures should be of concern. Since refrigerated storage is no guarantee of protection against growth of L. monocytogenes, every precaution should be taken to prevent contamination of certain foods by this organism.CHOCOLATELISTERIA MONOCYTOGENESBACTERIAPOLUCIONINOCULACIONJournal of Food Protection (EUA)
institution IICA
collection Koha
country Costa Rica
countrycode CR
component Bibliográfico
access En linea
databasecode cat-sibiica
tag biblioteca
region America Central
libraryname Sistema de Bibliotecas IICA/CATIE
topic CHOCOLATE
LISTERIA MONOCYTOGENES
BACTERIA
POLUCION
INOCULACION
CHOCOLATE
LISTERIA MONOCYTOGENES
BACTERIA
POLUCION
INOCULACION
spellingShingle CHOCOLATE
LISTERIA MONOCYTOGENES
BACTERIA
POLUCION
INOCULACION
CHOCOLATE
LISTERIA MONOCYTOGENES
BACTERIA
POLUCION
INOCULACION
113471 Rosenow, E.M.
90661 Marth, E.H.
Growth of Listeria monocytogenes in skim, whole and chocolate milk, and in whipping cream during incubation at 4, 8, 13, 21 and 35 grade centigrade
description Autoclaved samples of skim, whole, and chocolate milk and of whipping cream were inoculated with Listeria monocytogenes (one to four strains were tested individually, depending on the experiment) and incubated at 4, 8, 13, 21 or 35 grade centigrade. Growth curves were then derived and generation times and maximum populations calculated for each combination of strain, product, and temperature. The growth rate of L. monocytogenes was similar in all four products at a given incubation temperature and increased with an increase in temperature. Doubling times over all products and strains were 41 min (35 grade centigrade), 1 h 43 min-1 h 55 min (21 grade centigrade), 4 h 27 min-6 h 55 min (13 grade centigrade), 8 h 40 min-14 h 33 min (8 grade centigrade), and 29 h 44 min-45 h 33 min (4 grade centigrade). In each instance, maximum populations reached were at least 10 exponent 7 cells/ml, with highest numbers consistently produced in chocolate milk (at least 10 times greater than in skim or whole milk or cream at any temperature). Little decrease in final numbers occurred with extended storage at the incubation temperature being studied. All results were analyzed statistically to determine magnitude and source of variation. Observed differences in data resulted from interactive effects between strain, product, and temperature. Therefore, no single factor can be considered as the sole cause of a particular finding. That L. monocytogenes can attain such high populations at low temperatures should be of concern. Since refrigerated storage is no guarantee of protection against growth of L. monocytogenes, every precaution should be taken to prevent contamination of certain foods by this organism.
format
topic_facet CHOCOLATE
LISTERIA MONOCYTOGENES
BACTERIA
POLUCION
INOCULACION
author 113471 Rosenow, E.M.
90661 Marth, E.H.
author_facet 113471 Rosenow, E.M.
90661 Marth, E.H.
author_sort 113471 Rosenow, E.M.
title Growth of Listeria monocytogenes in skim, whole and chocolate milk, and in whipping cream during incubation at 4, 8, 13, 21 and 35 grade centigrade
title_short Growth of Listeria monocytogenes in skim, whole and chocolate milk, and in whipping cream during incubation at 4, 8, 13, 21 and 35 grade centigrade
title_full Growth of Listeria monocytogenes in skim, whole and chocolate milk, and in whipping cream during incubation at 4, 8, 13, 21 and 35 grade centigrade
title_fullStr Growth of Listeria monocytogenes in skim, whole and chocolate milk, and in whipping cream during incubation at 4, 8, 13, 21 and 35 grade centigrade
title_full_unstemmed Growth of Listeria monocytogenes in skim, whole and chocolate milk, and in whipping cream during incubation at 4, 8, 13, 21 and 35 grade centigrade
title_sort growth of listeria monocytogenes in skim, whole and chocolate milk, and in whipping cream during incubation at 4, 8, 13, 21 and 35 grade centigrade
publishDate Jun
work_keys_str_mv AT 113471rosenowem growthoflisteriamonocytogenesinskimwholeandchocolatemilkandinwhippingcreamduringincubationat481321and35gradecentigrade
AT 90661martheh growthoflisteriamonocytogenesinskimwholeandchocolatemilkandinwhippingcreamduringincubationat481321and35gradecentigrade
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