Modelling the Effect of Salt Concentration on the Fate of <i>Listeria monocytogenes</i> Isolated from Costa Rican Fresh Cheeses
Guiomar D. Posada-Izquierdo,
Beatriz Mazón-Villegas,
Mauricio Redondo-Solano,
Alejandra Huete-Soto,
Diana Víquez-Barrantes,
Antonio Valero,
Paula Fallas-Jiménez,
Rosa María García-Gimeno
Affiliations
Guiomar D. Posada-Izquierdo
Departamento de Bromatología y Tecnología de los Alimentos, Facultad de Veterinaria, Campus de Excelencia Internacional Agroalimentario (ceiA3), Universidad de Córdoba, Ctra. Madrid-Cádiz km 396A, 14014 Córdoba, Spain
Beatriz Mazón-Villegas
Escuela de Ingeniería de Biosistemas, Cuidad Universitaria Rodrigo Facio, Universidad de Costa Rica, 11501-2060 San José, Costa Rica
Mauricio Redondo-Solano
Research Center for Tropical Diseases (CIET) and Food Microbiology Research and Training Laboratory (LIMA), Faculty of Microbiology, Ciudad Universitaria Rodrigo Facio, University of Costa Rica, 11501-2060 San José, Costa Rica
Alejandra Huete-Soto
Research Center for Tropical Diseases (CIET) and Food Microbiology Research and Training Laboratory (LIMA), Faculty of Microbiology, Ciudad Universitaria Rodrigo Facio, University of Costa Rica, 11501-2060 San José, Costa Rica
Diana Víquez-Barrantes
National Center for Food Science and Technology (CITA), Ciudad Universitaria Rodrigo Facio, University of Costa Rica, 11501-2060 San José, Costa Rica
Antonio Valero
Departamento de Bromatología y Tecnología de los Alimentos, Facultad de Veterinaria, Campus de Excelencia Internacional Agroalimentario (ceiA3), Universidad de Córdoba, Ctra. Madrid-Cádiz km 396A, 14014 Córdoba, Spain
Paula Fallas-Jiménez
Research Center for Tropical Diseases (CIET) and Food Microbiology Research and Training Laboratory (LIMA), Faculty of Microbiology, Ciudad Universitaria Rodrigo Facio, University of Costa Rica, 11501-2060 San José, Costa Rica
Rosa María García-Gimeno
Departamento de Bromatología y Tecnología de los Alimentos, Facultad de Veterinaria, Campus de Excelencia Internacional Agroalimentario (ceiA3), Universidad de Córdoba, Ctra. Madrid-Cádiz km 396A, 14014 Córdoba, Spain
“Turrialba cheese” is a Costa Rican fresh cheese highly appreciated due to its sensory characteristics and artisanal production. As a ready-to-eat dairy product, its formulation could support Listeria monocytogenes growth. L. monocytogenes was isolated from 14.06% of the samples and the pathogen was able to grow under all tested conditions. Due to the increasing demand for low-salt products, the objective of this study was to determine the effect of salt concentration on the growth of pathogen isolates obtained from local cheese. Products from retail outlets in Costa Rica were analyzed for L. monocytogenes. These isolates were used to determine growth at 4 °C for different salt concentration (0.5–5.2%). Kinetic curves were built and primary and secondary models developed. Finally, a validation study was performed using literature data. The R2 and Standard Error of fit of primary models were ranked from 0.964–0.993, and 0.197–0.443, respectively. An inverse relationship was observed between growth rate and salt concentration. A secondary model was obtained, with R2 = 0.962. The model was validated, and all values were Bf > 1, thus providing fail-safe estimations. These data were added to the free and easy-to-use predictive microbiology software “microHibro” which is used by food producers and regulators to assist in decision-making.
