Dataset Information

Growth Potential of Listeria monocytogenes on Refrigerated Spinach and Rocket Leaves in Modified Atmosphere Packaging.

ABSTRACT: Minimally processed ready-to-eat (RTE) vegetables are increasingly consumed for their health benefits. However, they also pose a risk of being ingested with food-borne pathogens. The present study investigated the ability of RTE spinach and rocket to support the growth of Listeria monocytogenes as previous studies provided contradicting evidence. Findings were compared to growth on iceberg lettuce that has repeatedly been shown to support growth. Products were inoculated with a three-strain mix of L. monocytogenes at 10 and 100 cfu g-1 and stored in modified atmosphere (4 kPa O2, 8 kPa CO2) at 8 °C over 7-9 days. Spinach demonstrated the highest growth potential rate of 2 to 3 log10 cfu g-1 over a 9-day period with only marginal deterioration in its visual appearance. Growth potential on rocket was around 2 log10 cfu g-1 over 9 days with considerable deterioration in visual appearance. Growth potential of iceberg lettuce was similar to that of rocket over a 7-day period. Growth curves fitted closely to a linear growth model, indicating none to limited restrictions of growth over the duration of storage. The high growth potentials of L. monocytogenes on spinach alongside the limited visual deterioration highlight the potential risks of consuming this raw RTE food product when contaminated.

SUBMITTER: Culliney P

PROVIDER: S-EPMC7555703 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature

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Growth Potential of <i>Listeria monocytogenes</i> on Refrigerated Spinach and Rocket Leaves in Modified Atmosphere Packaging.

Culliney Paul P Schmalenberger Achim A

Foods (Basel, Switzerland) 20200901 9

Minimally processed ready-to-eat (RTE) vegetables are increasingly consumed for their health benefits. However, they also pose a risk of being ingested with food-borne pathogens. The present study investigated the ability of RTE spinach and rocket to support the growth of <i>Listeria monocytogenes</i> as previous studies provided contradicting evidence. Findings were compared to growth on iceberg lettuce that has repeatedly been shown to support growth. Products were inoculated with a three-stra ...[more]

PMID: 32882945

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Project description:The sessile biofilms of Vibrio parahaemolyticus and Listeria monocytogenes have increasingly become a critical threat in seafood safety. This study aimed to evaluate the effects of modified atmospheres on the formation ability of V. parahaemolyticus and L. monocytogenes biofilms. The stress responses of bacterial biofilm formation to modified atmospheres including anaerobiosis (20% carbon dioxide, 80% nitrogen), micro-aerobiosis (20% oxygen, 80% nitrogen), and aerobiosis (60% oxygen, 40% nitrogen) were illuminated by determining the live cells, chemical composition analysis, textural parameter changes, expression of regulatory genes, etc. Results showed that the biofilm formation ability of V. parahaemolyticus was efficiently decreased, supported by the fact that the modified atmospheres significantly reduced the key chemical composition [extracellular DNA (eDNA) and extracellular proteins] of the extracellular polymeric substance (EPS) and negatively altered the textural parameters (biovolume, thickness, and bio-roughness) of biofilms during the physiological conversion from anaerobiosis to aerobiosis, while the modified atmosphere treatment increased the key chemical composition of EPS and the textural parameters of L. monocytogenes biofilms from anaerobiosis to aerobiosis. Meanwhile, the expression of biofilm formation genes (luxS, aphA, mshA, oxyR, and opaR), EPS production genes (cpsA, cpsC, and cpsR), and virulence genes (vopS, vopD1, vcrD1, vopP2?, and vcrD2?) of V. parahaemolyticus was downregulated. For the L. monocytogenes cells, the expression of biofilm formation genes (flgA, flgU, and degU), EPS production genes (Imo2554, Imo2504, inlA, rmlB), and virulence genes (vopS, vopD1, vcrD1, vopP2?, and vcrD2?) was upregulated during the physiological conversion. All these results indicated that the modified atmospheres possessed significantly different regulation on the biofilm formation of Gram-negative V. parahaemolyticus and Gram-positive L. monocytogenes, which will provide a novel insight to unlock the efficient control of Gram-negative and Gram-positive bacteria in modified-atmosphere packaged food.

Dataset Information

Growth Potential of Listeria monocytogenes on Refrigerated Spinach and Rocket Leaves in Modified Atmosphere Packaging.

Publications

Growth Potential of <i>Listeria monocytogenes</i> on Refrigerated Spinach and Rocket Leaves in Modified Atmosphere Packaging.

Similar Datasets

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