Growth Potential of Listeria monocytogenes in Vegan Salami

The increasing demand for plant-based products has raised concerns regarding the potential presence and growth of Listeria monocytogenes in ready-to-eat products such as plant-based deli slices. In this study, a challenge test was performed to evaluate the growth potential of L. monocytogenes in a v...

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Main Authors: Signe Magnussen, Emma Bergenkvist, Karin Söderqvist
Format: Article
Language:English
Published: Elsevier 2025-06-01
Series:Journal of Food Protection
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Online Access:http://www.sciencedirect.com/science/article/pii/S0362028X25000900
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author Signe Magnussen
Emma Bergenkvist
Karin Söderqvist
author_facet Signe Magnussen
Emma Bergenkvist
Karin Söderqvist
author_sort Signe Magnussen
collection DOAJ
description The increasing demand for plant-based products has raised concerns regarding the potential presence and growth of Listeria monocytogenes in ready-to-eat products such as plant-based deli slices. In this study, a challenge test was performed to evaluate the growth potential of L. monocytogenes in a vegan salami product. This particular product not only exhibited the highest pH value among the eight similar products available in the supermarket but also had a water activity of 0.96. Additionally, the vegan salami contained no chemical additives with antimicrobial activity, thus possibly representing a “worst case” product for enabling bacterial growth. The product samples were inoculated with two strains of L. monocytogenes and stored at 8 °C during their remaining shelf-life (approximately 30 days). The concentration of L. monocytogenes was measured at the beginning of the test, at three intermediate time points throughout, and at the end. Water activity and pH were also assessed during the challenge test, and noninoculated samples were analyzed for total bacterial counts (TBCs) and screened for the most prevalent bacterial species with MALDI-TOF-MS. A growth potential (δ) of 4.4 log10 cfu/g was observed for the vegan salami, i.e. L. monocytogenes levels increasing from an initial inoculation level of approximately 2.4 log10 to a maximum of 6.8 log10 cfu/g during the challenge test. The screening investigation revealed that species of the genera Carnobacterium and Leuconostoc were the most prevalent. To summarize, the findings from this study demonstrate that there are currently plant-based deli slices on the market that possess the potential to support the growth of L. monocytogenes.
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spelling doaj-art-2201b6a4332b4a9c8637557800d11dd82025-08-20T03:22:42ZengElsevierJournal of Food Protection0362-028X2025-06-0188710053810.1016/j.jfp.2025.100538Growth Potential of Listeria monocytogenes in Vegan SalamiSigne Magnussen0Emma Bergenkvist1Karin Söderqvist2Department of Animal Biosciences, Swedish University of Agricultural Sciences, Box 7023, 750 07 Uppsala, SwedenDepartment of Animal Biosciences, Swedish University of Agricultural Sciences, Box 7023, 750 07 Uppsala, SwedenCorresponding author.; Department of Animal Biosciences, Swedish University of Agricultural Sciences, Box 7023, 750 07 Uppsala, SwedenThe increasing demand for plant-based products has raised concerns regarding the potential presence and growth of Listeria monocytogenes in ready-to-eat products such as plant-based deli slices. In this study, a challenge test was performed to evaluate the growth potential of L. monocytogenes in a vegan salami product. This particular product not only exhibited the highest pH value among the eight similar products available in the supermarket but also had a water activity of 0.96. Additionally, the vegan salami contained no chemical additives with antimicrobial activity, thus possibly representing a “worst case” product for enabling bacterial growth. The product samples were inoculated with two strains of L. monocytogenes and stored at 8 °C during their remaining shelf-life (approximately 30 days). The concentration of L. monocytogenes was measured at the beginning of the test, at three intermediate time points throughout, and at the end. Water activity and pH were also assessed during the challenge test, and noninoculated samples were analyzed for total bacterial counts (TBCs) and screened for the most prevalent bacterial species with MALDI-TOF-MS. A growth potential (δ) of 4.4 log10 cfu/g was observed for the vegan salami, i.e. L. monocytogenes levels increasing from an initial inoculation level of approximately 2.4 log10 to a maximum of 6.8 log10 cfu/g during the challenge test. The screening investigation revealed that species of the genera Carnobacterium and Leuconostoc were the most prevalent. To summarize, the findings from this study demonstrate that there are currently plant-based deli slices on the market that possess the potential to support the growth of L. monocytogenes.http://www.sciencedirect.com/science/article/pii/S0362028X25000900Challenge testListeriosisMeat substitutePlant-based deli slices
spellingShingle Signe Magnussen
Emma Bergenkvist
Karin Söderqvist
Growth Potential of Listeria monocytogenes in Vegan Salami
Journal of Food Protection
Challenge test
Listeriosis
Meat substitute
Plant-based deli slices
title Growth Potential of Listeria monocytogenes in Vegan Salami
title_full Growth Potential of Listeria monocytogenes in Vegan Salami
title_fullStr Growth Potential of Listeria monocytogenes in Vegan Salami
title_full_unstemmed Growth Potential of Listeria monocytogenes in Vegan Salami
title_short Growth Potential of Listeria monocytogenes in Vegan Salami
title_sort growth potential of listeria monocytogenes in vegan salami
topic Challenge test
Listeriosis
Meat substitute
Plant-based deli slices
url http://www.sciencedirect.com/science/article/pii/S0362028X25000900
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