Inoculation density is affecting growth conditions of Listeria monocytogenes on fresh cut lettuce.
World J Microbiol Biotechnol
; 33(12): 217, 2017 Nov 27.
Article
en En
| MEDLINE
| ID: mdl-29181800
ABSTRACT
Listeria monocytogenes is a particular risk for the ready-to-eat food sector because of its ability to grow in various environmental conditions. In the literature, growth and survival of L. monocytogenes on food is tested using inoculation densities ranging from less than 102 to over 105 CFU g-1. Inoculation densities on food have been rarely tested as a factor for growth. In this study, inoculation densities from 102 to 105 of L. monocytogenes were tested on iceberg lettuce (Lactuca sativa) in modified atmospheres and air in model packages at 4 and 8 °C to identify any potential inoculation density effects. On days 0, 2, 5 and 7, L. monocytogenes was extracted from the lettuce surface and enumerated via selective media. The resulting growth curves identified a significant inoculation density effect at 4 and 8 °C with significantly higher amounts of growth (1-2 logs) when lettuce was inoculated at 102 CFU g-1 as opposed to 104 and 105 CFU g-1. In contrast, the use of different atmospheres had limited influence on growth of L. monocytogenes. In conclusion, greater emphasis on inoculation density of L. monocytogenes should be taken in inoculation experiments when confirmation of growth or the efficacies of growth inhibiting treatments are tested on ready-to-eat food such as lettuce.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Lactuca
/
Listeria monocytogenes
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
World J Microbiol Biotechnol
Año:
2017
Tipo del documento:
Article
País de afiliación:
Irlanda