<abstract xmlns="http://www.w3.org/1999/xhtml"><bold>Introduction:</bold> The purpose of the study was to determine and model the growth rates of <italic>L. monocytogenes</italic> in cooked cured ham stored at various temperatures.<bold>Material and Methods:</bold> Samples of cured ham were artificially contaminated with a mixture of three <italic>L. monocytogenes</italic> strains and stored at 3, 6, 9, 12, or 15°C for 16 days. The number of listeriae was determined after 0, 1, 2, 3, 5, 7, 9, 12, 14, and 16 days. A series of decimal dilutions were prepared from each sample and plated onto ALOA agar, after which the plates were incubated at 37°C for 48 h under aerobic conditions. The bacterial counts were logarithmised and analysed statistically. Five repetitions of the experiment were performed.<bold>Results:</bold> Both storage temperature and time were found to significantly influence the growth rate of listeriae (P &lt; 0.01). The test bacteria growth curves were fitted to three primary models: the Gompertz, Baranyi, and logistic. The mean square error (MSE) and Akaike’s information criterion (AIC) were calculated to evaluate the goodness of fit. It transpired that the logistic model fit the experimental data best. The natural logarithms of <italic>L. monocytogenes’</italic> mean growth rates from this model were fitted to two secondary models: the square root and polynomial.<bold>Conclusion:</bold> Modelling in both secondary types can predict the growth rates of <italic>L. monocytogenes</italic> in cooked cured ham stored at each studied temperature, but mathematical validation showed the polynomial model to be more accurate.</abstract>

Introduction: The purpose of the study was to determine and model the growth rates of L. monocytogenes in cooked cured ham stored at various temperatures.Material and Methods: Samples of cured ham were artificially contaminated with a mixture of three L. monocytogenes strains and stored at 3, 6, 9, 12, or 15°C for 16 days. The number of listeriae was determined after 0, 1, 2, 3, 5, 7, 9, 12, 14, and 16 days. A series of decimal dilutions were prepared from each sample and plated onto ALOA agar, after which the plates were incubated at 37°C for 48 h under aerobic conditions. The bacterial counts were logarithmised and analysed statistically. Five repetitions of the experiment were performed.Results: Both storage temperature and time were found to significantly influence the growth rate of listeriae (P < 0.01). The test bacteria growth curves were fitted to three primary models: the Gompertz, Baranyi, and logistic. The mean square error (MSE) and Akaike’s information criterion (AIC) were calculated to evaluate the goodness of fit. It transpired that the logistic model fit the experimental data best. The natural logarithms of L. monocytogenes’ mean growth rates from this model were fitted to two secondary models: the square root and polynomial.Conclusion: Modelling in both secondary types can predict the growth rates of L. monocytogenes in cooked cured ham stored at each studied temperature, but mathematical validation showed the polynomial model to be more accurate.

Modelling the growth rate of <italic>Listeria monocytogenes</italic> in cooked ham stored at different temperatures

Department of Food Hygiene and Public Health, Faculty of Veterinary Medicine, University of Life Sciences, 02-776 Warsaw,

Chair of Dairy and Quality Management, Faculty of Food Sciences, University of Warmia and Mazury in Olsztyn, 10-719 Olsztyn,

Journal of Veterinary Research

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Modelling the growth rate of  in cooked ham stored at different temperatures

Introduction: The purpose of the study was to determine and model the growth rates of L. monocytogenes in cooked cured ham stored at various...

Modelling the growth rate of Listeria monocytogenes in cooked ham stored at different temperatures

Published Online: Apr 04, 2017

Page range: 45 - 51

Received: Aug 23, 2016

Accepted: Mar 10, 2017

DOI: https://doi.org/10.1515/jvetres-2017-0006

Keywords
ham, storage, predictive modelling

© 2017 Jacek Szczawiński et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Modelling the growth rate of Listeria monocytogenes in cooked ham stored at different temperatures

Published Online: Apr 04, 2017

Page range: 45 - 51

Received: Aug 23, 2016

Accepted: Mar 10, 2017

DOI: https://doi.org/10.1515/jvetres-2017-0006

Keywordsham, storage, predictive modelling

© 2017 Jacek Szczawiński et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
ham, storage, predictive modelling