Modeling The Growth Of Listeria Monocytogenes In Soft Goat’s Cheese ‘Jben’ Under Various Storage Temperatures

Soft goat cheese
L. monocytogenes
Predictive microbiology
Author

Boussif, K., Elidrissi, A., Elmoslih, A., Ezzaky, Y., Zanzan, M., & Achemchem, F.

Doi

10.5281/zenodo.14787615

Citation (APA 7)

Boussif, K., Elidrissi, A., Elmoslih, A., Ezzaky, Y., Zanzan, M., & Achemchem, F. (2024). Modeling The Growth Of Listeria Monocytogenes In Soft Goat’s Cheese “Jben” Under Various Storage Temperatures. 16th AgroStat Conference (AgroStat 2024) (AGROSTAT2024), Bragança, Portugal. Zenodo. https://doi.org/10.5281/zenodo.14787615

Abstract

Outbreaks of listeriosis have been associated with cheese consumption. This study focused on goat’s Jben, a traditional Moroccan dairy product, to evaluate and model the growth of Listeria monocytogenes at different storage temperatures (4–40 °C). Lab-scale Jben samples were prepared using a traditional Moroccan recipe and inoculated with a threestrain cocktail of L. monocytogenes at approximately 2 log cfu/g. These inoculated samples (pH = 5.85 ± 0.05, aw = 0.92 ± 0.001) were stored under various isothermal conditions (4, 20, 25, 30, 35, and 40 °C) and analyzed microbiologically using plate count methodology to quantify pathogen levels. Predictive microbiology models, based on mathematical equations, were used to estimate microbial behavior in the product. The Baranyi model was applied to describe the growth kinetics of cheeses stored at constant temperatures and was integrated with the Ratkowsky model through global regression analysis. This approach correlated L. monocytogenes concentrations with storage temperature and time. Results indicated that the growth potential of L. monocytogenes increased with higher storage temperatures. Analysis was performed using MATLAB, and the estimated Ratkowsky model parameters were a = 0.0066 Log cfu/h⋅°C, b = 0.1683 /°C, Tmin = 2 °C and Tmax = 49.3 °C. Growth rates, fitted with the extended Ratkowsky square root model, ranged from 0.001 to 0.0345 log cfu/h at temperatures from 4 to 40 °C. The proposed model aims to predict L. monocytogenes growth across a broad range of storage temperatures, providing a basis for informed decisions regarding the microbiological safety of Jben.