Listeria monocytogenes under acid and antimicrobial compounds stress: survival and pathogenic potential in orange juice

Listeria monocytogenes poses significant risks in acidic foods like unpasteurized fruit juices due to its capacity to survive under stressful conditions. This study evaluated L. monocytogenes survival in orange juice following acid adaptation and exposure to antimicrobial compounds. Acid adaptation...

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Detalles Bibliográficos
Autores: Bainotti, Maria Belén, Colás Medà, Pilar, Viñas Almenar, Inmaculada, Alegre Vilas, Isabel
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2025
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:10459.1/468838
Acceso en línea:https://doi.org/10.3390/beverages11040096
https://hdl.handle.net/10459.1/468838
Access Level:acceso abierto
Palabra clave:L. monocytogenes
Nisin
Gastrointestinal simulation
Acid stress
Orange juice
Descripción
Sumario:Listeria monocytogenes poses significant risks in acidic foods like unpasteurized fruit juices due to its capacity to survive under stressful conditions. This study evaluated L. monocytogenes survival in orange juice following acid adaptation and exposure to antimicrobial compounds. Acid adaptation was induced using glucose-supplemented or citric acidacidified media, followed by the evaluation of pathogen survival in orange juice stored at 4 ◦C, 15 ◦C, and 25 ◦C. While glucose adaptation reduced the medium pH to 4.5 and enabled bacterial growth (up to 7.5 total log CFU/mL), citric acid exposure caused around 1.4 log units of reduction. Contrary to expectations, the survival of acid-adapted cells was lower than that of non-acid-adapted cells, particularly in orange juice stored at 25 ◦C (around 4.8 vs. 1.4 log units of reduction after 6 days). The behaviour of non-acid-adapted cells was evaluated in response to different antimicrobial compounds (citral, coumaric acid, nisin, sinapic acid, and vanillin). Nisin was the most effective, achieving a reduction of about 3.5 log units with a dose of 2 mL/L. Nisin-treated cells also showed reduced survival during simulated gastrointestinal assays (around 1.5 log units of reduction). These results challenge the assumption that acid adaptation universally enhances survival in acidic matrices and highlight nisin’s dual role in microbial control and pathogenicity mitigation. This work underscores the need for tailored stress adaptation studies and natural antimicrobial applications to improve food safety in minimally processed fruit juices.