Dynamic Modelling of Listeria monocytogenes Growth in a Milk Model Medium as Affected by pH and Selected Lactic Acid Bacteria Strains

Citation (APA 7)

Loforte, Y., Zanzan, M., Cadavez, V., & Gonzales-Barron, U. (2025). Dynamic modelling of Listeria monocytogenes growth in a milk model medium as affected by pH and selected lactic acid bacteria strains. Foods, 14(23), 3999. https://doi.org/10.3390/foods14233999

Abstract

Three lactic acid bacteria strains—Leuconostoc mesenteroides, Lacticaseibacillus paracasei, and Loigolactobacillus coryniformis—were evaluated for their ability to limit the growth of Listeria monocytogenes in heat-treated reconstituted milk adjusted to initial pH 5.5, 6.0, or 6.5. Monoculture and co-culture challenge tests were modeled using a pH-driven approach and a Jameson-effect model; the pH-driven model yielded more precise growth estimates. In monoculture, L. mesenteroides exhibited the fastest development across pH levels, while in co-culture it most effectively curtailed L. monocytogenes by reducing growth rates. Increasing initial milk pH led to higher maximum concentrations of the pathogen in both mono- and co-culture, though all LAB strains reduced the final pathogen load. Adjusting milk toward acidic pH before fermentation provides an additional barrier against L. monocytogenes.