Growth and survival of Salmonella enterica and Listeria monocytogenes on fresh-cut produce and their juice extracts: Impacts and interactions of food matrices and temperature abuse conditions

Effective cold chain management is a critical component of food safety practice. In this study, we examined the impact of commonly encountered temperature abuse scenarios on the proliferation of Salmonella enterica and Listeria monocytogenes on fresh-cut cantaloupe. Inoculated fresh-cut cantaloupe cubes were subjected to various temperature abuse conditions, and the growth of S. enterica and L. monocytogenes was determined. During 1 week of storage, Salmonella cell counts on fresh-cut cantaloupe increased by −0.26, 1.39, and 2.23 log units at 4°C (control), 8°C, and 12°C (chronic temperature abuse), respectively, whereas that of L. monocytogenes increased by 0.75, 2.86, and 4.17 log units. Under intermittent temperature abuse conditions, where storage temperature fluctuated twice daily to room temperature for 30 min, Salmonella cell count increased by 2.18 log units, whereas that of L. monocytogenes increased by 1.86 log units. In contrast, terminal acute temperature abuses for 2 to 4 h resulted in upwards to 0.6 log unit for Salmonella, whereas the effect on L. monocytogenes was less significant compared with L. monocytogenes on cut cantaloupe stored at 4°C. Significant deterioration of produce visual quality and tissue integrity, as reflected by electrolyte leakage, was also observed under various temperature abuse conditions.

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Behavior of Listeria monocytogenes Inoculated on Cantaloupe Surfaces and Efficacy of Washing Treatments To Reduce Transfer from Rind to Fresh-Cut Pieces†

Journal of Food Protection ◽

10.4315/0362-028x-65.6.924 ◽

2002 ◽

Vol 65 (6) ◽

pp. 924-930 ◽

Cited By ~ 90

Author(s):

DIKE O. UKUKU ◽

WILLIAM FETT

Keyword(s):

Hydrogen Peroxide ◽

Listeria Monocytogenes ◽

Surface Treatment ◽

Growth And Survival ◽

Log Reduction ◽

Direct Inoculation ◽

Fresh Cut ◽

Native Microflora

Attachment and survival of Listeria monocytogenes on external surfaces (rind) of inoculated cantaloupe, resistance of the surviving bacteria to chlorine or hydrogen peroxide treatments, transfer of the pathogen from unsanitized and sanitized rinds to fresh-cut tissues during cutting and growth, and survival of L. monocytogenes on fresh-cut pieces of cantaloupe were investigated. Surface treatment with 70% ethanol to reduce the native microflora on treated melon, followed by immersion in a four-strain cocktail of L. monocytogenes (108 CFU/ml) for 10 min, deposited 4.2 log10 CFU/cm2 and 3.5 log10 CFU/cm2 of L. monocytogenes on treated and untreated cantaloupe rinds, respectively. L. monocytogenes survived on the treated or untreated cantaloupe rinds for up to 15 days during storage at 4 and 20°C, but populations declined by approximately 1 to 2 log10 CFU/cm2. Fresh-cut pieces prepared from inoculated whole cantaloupes stored at 4°C for 24 h after inoculation were positive for L. monocytogenes. Washing inoculated whole cantaloupes in solutions containing 1,000 ppm of chlorine or 5% hydrogen peroxide for 2 min at 1 to 15 days of storage at 4°C after inoculation resulted in a 2.0-to 3.5-log reduction in L. monocytogenes on the melon surface. Fresh-cut pieces prepared from the sanitized melons were negative for L. monocytogenes. After direct inoculation onto fresh-cut pieces, L. monocytogenes survived, but did not grow, during 15 days of storage at 4°C. Growth was evident by 4 h of storage at 8 and 20°C. It is concluded that sanitizing with chlorine or hydrogen peroxide has the potential to reduce or eliminate the transfer of L. monocytogenes on melon surfaces to fresh-cut pieces during cutting.

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Biocontrol of the Food-Borne Pathogens Listeria monocytogenes and Salmonella enterica Serovar Poona on Fresh-Cut Apples with Naturally Occurring Bacterial and Yeast Antagonists

Applied and Environmental Microbiology ◽

10.1128/aem.72.2.1135-1140.2006 ◽

2006 ◽

Vol 72 (2) ◽

pp. 1135-1140 ◽

Cited By ~ 92

Author(s):

Britta Leverentz ◽

William S. Conway ◽

Wojciech Janisiewicz ◽

Maribel Abadias ◽

Cletus P. Kurtzman ◽

...

Keyword(s):

Listeria Monocytogenes ◽

Salmonella Enterica ◽

Human Pathogens ◽

Food Borne Pathogens ◽

Naturally Occurring ◽

Food Borne ◽

Different Temperatures ◽

Apple Tissue ◽

Higher Temperature ◽

Fresh Cut

ABSTRACT Fresh-cut apples contaminated with either Listeria monocytogenes or Salmonella enterica serovar Poona, using strains implicated in outbreaks, were treated with one of 17 antagonists originally selected for their ability to inhibit fungal postharvest decay on fruit. While most of the antagonists increased the growth of the food-borne pathogens, four of them, including Gluconobacter asaii (T1-D1), a Candida sp. (T4-E4), Discosphaerina fagi (ST1-C9), and Metschnikowia pulcherrima (T1-E2), proved effective in preventing the growth or survival of food-borne human pathogens on fresh-cut apple tissue. The contaminated apple tissue plugs were stored for up to 7 days at two different temperatures. The four antagonists survived or grew on the apple tissue at 10 or 25°C. These four antagonists reduced the Listeria monocytogenes populations and except for the Candida sp. (T4-E4), also reduced the S. enterica serovar Poona populations. The reduction was higher at 25°C than at 10°C, and the growth of the antagonists, as well as pathogens, increased at the higher temperature.

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