Growth of Listeria monocytogenes in Skim, Whole and Chocolate Milk, and in Whipping Cream during Incubation at 4, 8, 13, 21 and 35°C

摘要: Autoclaved samples of skim, whole, and chocolate milk whipping cream were inoculated with Listeria monocytogenes (one to four strains tested individually, depending on the experiment) incubated at 4, 8, 13, 21 or 35°C. Growth curves then derived generation times maximum populations calculated for each combination strain, product, temperature. The growth rate L. was similar in all products a given incubation temperature increased an increase Doubling over 41 min (35°C), 1 h 43 min-1 55 (21°C), 4 27 min-6 (13°C), 8 40 min-14 33 (8°C), 29 44 min-45 (4°C). In instance, reached least 107 cells/ml, highest numbers consistently produced (at 10 greater than skim whole any temperature). Little decrease final occurred extended storage being studied. All results analyzed statistically determine magnitude source variation. Observed differences data resulted from interactive effects between Therefore, no single factor can be considered as sole cause particular finding. That attain such high low temperatures should concern. Since refrigerated is guarantee protection against , every precaution taken prevent contamination certain foods by this organism.