Fate of Listeria monocytogenes Serotypes on Frozen Mixed Vegetables During Consumer‐Simulated Thawing and Storage
- Division of Food Processing Science and Technology U.S. Food and Drug Administration Bedford Park Illinois USA
- Minority Science and Engineering Improvement Program (MSEIP), U.S. Food and Drug Administration Bedford Park Illinois USA
- Department of Food Science and Nutrition, Institute for Food Safety and Health Illinois Institute of Technology Bedford Park Illinois USA
- Agricultural Research Service, Eastern Regional Research Center U.S. Department of Agriculture Wyndmoor Pennsylvania USA
- Office of Food Safety U.S. Food and Drug Administration College Park Maryland USA
ABSTRACT
Recent outbreaks and recalls associated with frozen vegetables in the United States and Europe have been linked to Listeria monocytogenes . This study aims to understand the extent to which frozen vegetables support the growth of L. monocytogenes once thawed and held at different temperatures. Six L. monocytogenes strains, two of each from serotypes 1/2a, 1/2b, and 4b, were individually inoculated onto frozen vegetables and stored at −18°C for 7 days. After 7 days, the vegetables were thawed and stored at 5°C or 10°C for up to 14 days or at 25°C for up to 7 days. L. monocytogenes was enumerated from the thawed vegetables throughout the storage period. Population data were fitted to the primary Baranyi model to estimate growth rates and lag phase durations; the secondary Ratkowsky square root model was used to model the relationship of the growth rates with storage temperature. Five of the L. monocytogenes strains survived and grew on the thawed vegetables (population increases of > 1 log CFU/g) stored at 5°C, and all six of the strains proliferated at 10°C and 25°C (population increases of > 3 log CFU/g after 14 days and > 4 log CFU/g after 7 days, respectively). A secondary model was successfully generated based on the growth rates of the six L. monocytogenes strains on the thawed vegetables ( r 2 = 0.8888, RMSE = 0.2057). Results from this study fill a data gap associated with L. monocytogenes survival on thawed vegetables and can be used to determine safe handling and storage practices for these products to protect public health.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 2568204
- Journal Information:
- Journal of Food Safety, Journal Name: Journal of Food Safety Journal Issue: 3 Vol. 45; ISSN 0149-6085
- Publisher:
- Wiley-BlackwellCopyright Statement
- Country of Publication:
- United States
- Language:
- English