Comparison of Probabilistic and Deterministic Predictions of Time to Growth of Listeria monocytogenes as Affected by pH and Temperature in Food
| Autor: | Leymaya Guevara, Antonio Martínez, Pablo S. Fernández, Marina Muñoz-Cuevas |
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| Jazyk: | angličtina |
| Rok vydání: | 2011 |
| Předmět: |
Stochastic modelling
Lag Monte Carlo method Colony Count Microbial Growth Bacterial growth Biology medicine.disease_cause Models Biological Applied Microbiology and Biotechnology Microbiology Monte Carlo simulations Listeria monocytogenes medicine Food microbiology Food science Stochastic Processes Models Statistical Temperature Probabilistic logic Hydrogen-Ion Concentration Microbial risk assessment Stochastic models Food Food Microbiology Generalized extreme value distribution Animal Science and Zoology Monte Carlo Method Food Science |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | 8 pages, 2 tables, 4 figures.-- Online Ahead of Print: October 8, 2010.-- This is a copy of an article published in the Foodborne Pathogens and Disease © 2011 [copyright Mary Ann Liebert, Inc.]; Foodborne Pathogens and Disease is available online at: http://www.liebertonline.com. Stochastic models are useful for estimating the risk of foodborne illness and they can be integrated, besides other sources of variability, into microbial risk assessment. A stochastic approach to evaluate growth of two strains of Listeria monocytogenes influenced by different factors affecting microbial growth (pH and storage temperature) was performed. An individual-based approach of growth through optical density measurements was used. From results obtained, histograms of the lag phase were generated and distributions were fitted. Histograms presented increased variation when the factors applied were suboptimal for L. monocytogenes and they were combined. The extreme value distribution was ranked as the best one in most cases, whereas normal was the poorest fitting distribution. To evaluate the influence of pH and storage temperature on L. monocytogenes CECT 5672 in real food, commercial samples of courgette and carrot soup were inoculated with this pathogen. It was able to grow in both soups at storage temperatures from 4°C to 20°C. Using the distributions adjusted, predictions of time to growth (102 cfu/g) of L. monocytogenes were established by Monte Carlo simulation and they were compared with deterministic predictions and observations in foods. Dr. Marina Muñoz thanks Fundación CAJAMURCIA for awarding her a fellowship. This project was funded by Ministerio de Educación y Ciencia Español (ref. AGL 2006-13320-C03-02=ALI) |
| Databáze: | OpenAIRE |
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