Inactivation of Escherichia coli O157:H7 on radish and cabbage seeds by combined treatments with gaseous chlorine dioxide and heat at high relative humidity

Gaseous chlorine dioxide (ClO2) was evaluated for effectiveness in killing Salmonella, Escherichia coli O157:H7, and Listeria monocytogenes on fresh-cut lettuce, cabbage, and carrot and Salmonella, yeasts, and molds on apples, peaches, tomatoes, and onions. Inoculum (100 μl, ca. 6.8 log CFU) containing five serotypes of Salmonella enterica, five strains of E. coli O157:H7, or five strains of L. monocytogenes was deposited on the skin and cut surfaces of fresh-cut vegetables, dried for 30 min at 22°C, held for 20 h at 4°C, and then incubated for 30 min at 22°C before treatment. The skin surfaces of apples, peaches, tomatoes, and onions were inoculated with 100 μl of a cell suspension (ca. 8.0 log CFU) containing five serotypes of Salmonella, and inoculated produce was allowed to dry for 20 to 22 h at 22°C before treatment. Treatment with ClO2 at 4.1 mg/liter significantly (α = 0.05) reduced the population of foodborne pathogens on all produce. Reductions resulting from this treatment were 3.13 to 4.42 log CFU/g for fresh-cut cabbage, 5.15 to 5.88 log CFU/g for fresh-cut carrots, 1.53 to 1.58 log CFU/g for fresh-cut lettuce, 4.21 log CFU per apple, 4.33 log CFU per tomato, 1.94 log CFU per onion, and 3.23 log CFU per peach. The highest reductions in yeast and mold populations resulting from the same treatment were 1.68 log CFU per apple and 2.65 log CFU per peach. Populations of yeasts and molds on tomatoes and onions were not significantly reduced by treatment with 4.1 mg/liter ClO2. Substantial reductions in populations of pathogens on apples, tomatoes, and onions but not peaches or fresh-cut cabbage, carrot, and lettuce were achieved by treatment with gaseous ClO2 without markedly adverse effects on sensory qualities.

Download Full-text

Combined Treatment with Low Concentrations of Aqueous and Gaseous Chlorine Dioxide Inactivates Escherichia coli O157:H7 and Salmonella Typhimurium Inoculated on Paprika

Journal of Microbiology and Biotechnology ◽

10.4014/jmb.1611.11038 ◽

2017 ◽

Vol 27 (3) ◽

pp. 492-499 ◽

Cited By ~ 2

Author(s):

Hyun-Gyu Kim ◽

Kyung Bin Song

Keyword(s):

Escherichia Coli ◽

Salmonella Typhimurium ◽

Chlorine Dioxide ◽

Combined Treatment ◽

Escherichia Coli O157 ◽

Low Concentrations ◽

Gaseous Chlorine Dioxide

Download Full-text

Sanitizing radish seeds by simultaneous treatments with gaseous chlorine dioxide, high relative humidity, and mild heat

International Journal of Food Microbiology ◽

10.1016/j.ijfoodmicro.2016.08.022 ◽

2016 ◽

Vol 237 ◽

pp. 150-156 ◽

Cited By ~ 8

Author(s):

Jihyun Bang ◽

Moonhak Choi ◽

Hyeri Son ◽

Larry R. Beuchat ◽

Yoonsook Kim ◽

...

Keyword(s):

Relative Humidity ◽

Chlorine Dioxide ◽

High Relative Humidity ◽

Mild Heat ◽

Gaseous Chlorine Dioxide

Download Full-text

Survival and Growth of Enterohemorrhagic Escherichia coli O157:H7 in Cantaloupe and Watermelon

Journal of Food Protection ◽

10.4315/0362-028x-58.1.105 ◽

1995 ◽

Vol 58 (1) ◽

pp. 105-107 ◽

Cited By ~ 119

Author(s):

BRENDA A. DEL ROSARIO ◽

LARRY R. BEUCHAT

Keyword(s):

Escherichia Coli ◽

Relative Humidity ◽

Storage Period ◽

Enterohemorrhagic Escherichia Coli ◽

High Relative Humidity ◽

Escherichia Coli O157 ◽

Survival And Growth

The ability of Escherichia coli O157:H7 to survive and grow on cubes of cantaloupe and watermelon and on the external rind surface of these fruits was investigated. Populations of the pathogen increased on cubes stored at 25°C but remained constant at 5°C over a 34-h storage period. Growth was observed on the rind of melons stored under high relative humidity at 25°C for 14 to 22 days. The pathogen rapidly died on the rind surface of melons stored at 5°C.

Download Full-text

The combined effects of aqueous chlorine dioxide, fumaric acid, and ultraviolet-C with modified atmosphere packaging enriched in CO2 for inactivating preexisting microorganisms and Escherichia coli O157:H7 and Salmonella typhimurium inoculated on buckwheat sprouts

Postharvest Biology and Technology ◽

10.1016/j.postharvbio.2013.06.031 ◽

2013 ◽

Vol 86 ◽

pp. 118-124 ◽

Cited By ~ 13

Author(s):

Ho Hyun Chun ◽

Kyung Bin Song

Keyword(s):

Escherichia Coli ◽

Salmonella Typhimurium ◽

Chlorine Dioxide ◽

Fumaric Acid ◽

Modified Atmosphere Packaging ◽

Modified Atmosphere ◽

Escherichia Coli O157 ◽

Combined Effects ◽

Ultraviolet C

Download Full-text

Reduction of Escherichia coli O157:H7 Counts on Whole Fresh Apples by Treatment with Sanitizers

Journal of Food Protection ◽

10.4315/0362-028x-63.6.703 ◽

2000 ◽

Vol 63 (6) ◽

pp. 703-708 ◽

Cited By ~ 65

Author(s):

MARCY A. WISNIEWSKY ◽

BONITA A. GLATZ ◽

MARK L. GLEASON ◽

CHERYLL A. REITMEIER

Keyword(s):

Escherichia Coli ◽

Chlorine Dioxide ◽

Phosphate Buffer ◽

Phosphate Buffer Solution ◽

Escherichia Coli O157 ◽

Peroxyacetic Acid ◽

Water Control ◽

Buffer Solution ◽

E Coli ◽

Log Reduction

The objectives of this study were to determine if washing of whole apples with solutions of three different sanitizers (peroxyacetic acid, chlorine dioxide, or a chlorine-phosphate buffer solution) could reduce a contaminating nonpathogenic Escherichia coli O157:H7 population by 5 logs and at what sanitizer concentration and wash time such a reduction could be achieved. Sanitizers were tested at 1, 2, 4, 8, and 16 times the manufacturer's recommended concentration at wash times of 5, 10, and 15 min. Whole, sound Braeburn apples were inoculated with approximately 1 × 108 or 7 × 106 CFU per apple, stored for 24 h, then washed with sterile water (control) or with sanitizers for the prescribed time. Recovered bacteria were enumerated on trypticase soy agar. Washing with water alone reduced the recoverable population by almost 2 logs from the starting population; this can be attributed to physical removal of organisms from the apple surface. No sanitizer, when used at the recommended concentration, reduced the recovered E. coli population by 5 logs under the test conditions. The most effective sanitizer, peroxyacetic acid, achieved a 5-log reduction when used at 2.1 to 14 times its recommended concentration, depending on the length of the wash time. The chlorine-phosphate buffer solution reduced the population by 5 logs when used at 3 to 15 times its recommended concentration, depending on wash time. At no concentration or wash time tested did chlorine dioxide achieve the 5-log reduction.

Download Full-text

Growth of Salmonella and Other Foodborne Pathogens on Inoculated Inshell Pistachios during Simulated Delays between Hulling and Drying

Journal of Food Protection ◽

10.4315/0362-028x.jfp-18-450 ◽

2019 ◽

Vol 82 (5) ◽

pp. 815-825 ◽

Cited By ~ 3

Author(s):

MAHTA MOUSSAVI ◽

VANESSA LIEBERMAN ◽

CHRIS THEOFEL ◽

JAVAD BAROUEI ◽

LINDA J. HARRIS

Keyword(s):

Escherichia Coli ◽

Relative Humidity ◽

Foodborne Pathogens ◽

Lag Time ◽

Escherichia Coli O157 ◽

Contributing Factors ◽

Shell Surface ◽

E Coli ◽

Significant Growth ◽

Lower Maximum

ABSTRACT During harvest, pistachios are hulled, separated in water into floater and sinker streams (in large part on the basis of nut density), and then dried before storage. Higher prevalence and levels of Salmonella were previously observed in floater pistachios, but contributing factors are unclear. To examine the behavior of pathogens on hulled pistachios during simulated drying delays, floater and sinker pistachios collected from commercial processors were inoculated at 1 or 3 log CFU/g with cocktails of Salmonella and in some cases Escherichia coli O157:H7 or Listeria monocytogenes and incubated for up to 30 h at 37°C and 90% relative humidity. Populations were measured by plating onto tryptic soy agar and appropriate selective agars. In most cases, no significant growth (P > 0.05) of Salmonella was observed in the first 3 h after inoculation in hulled floaters and sinkers. Growth of Salmonella was greater on floater pistachios than on corresponding sinkers and on floater pistachios with ≥25% hull adhering to the shell surface than on corresponding floaters with <25% adhering hull. Maximum Salmonella populations (2 to 7 log CFU/g) were ∼2-log higher on floaters than on corresponding sinkers. The growth of E. coli O157:H7 and Salmonella on hulled pistachios was similar, but a longer lag time (approximately 11 h) and significantly lower maximum populations (4 versus 5 to 6 log CFU/g; P < 0.05) were predicted for L. monocytogenes. Significant growth of pathogens on hulled pistachios is possible when delays between hulling and drying are longer than 3 h, and pathogen growth is enhanced in the presence of adhering hull material.

Download Full-text

Survival of Escherichia coli O157:H7 in Full- and Reduced-Fat Pepperoni after Manufacture of Sticks, Storage of Slices at 4°C or 21°C under Air and Vacuum, and Baking of Slices on Frozen Pizza at 135, 191 and 246°C

Journal of Food Protection ◽

10.4315/0362-028x-61.4.383 ◽

1998 ◽

Vol 61 (4) ◽

pp. 383-389 ◽

Cited By ~ 36

Author(s):

NANCY G. FAITH ◽

RACHEL K. WIERZBA ◽

ANNE M. IHNOT ◽

ANN M. ROERING ◽

TIMOTHY D. LORANG ◽

...

Keyword(s):

Escherichia Coli ◽

Relative Humidity ◽

Starter Culture ◽

Escherichia Coli O157 ◽

Protein Ratio ◽

Direct Plating ◽

E Coli ◽

Reduced Fat ◽

Log10 Unit ◽

D Values

Pepperoni batter was prepared with fat contents of about 15, 20, and 32% (wt/wt) and inoculated with a pediococcal starter culture and ≥2.0 × 107 CFU/g of a five-strain inoculum of Escherichia coli O157:H7. The batter was fermented at 96°F (ca. 36°C) and 85% relative humidity (RH) to pH ≤ 4.8 and then dried at 55°F (ca. 13°C) and 65% RH to a moisture/protein ratio of ≤1.6:1. For storage, slices were packaged under air or vacuum and stored at 39°F (ca. 4°C) and 70°F (ca. 21°C). For baking, frozen slices were placed on retail frozen cheese pizzas that were subsequently baked at 275°F (ca. 135°C), 375°F (ca. 191°C), or 475°F (ca. 246°C) for 0 to 20 min. Appreciable differences related to fat levels were observed after drying; pathogen numbers decreased by 1.04, 1.31 and 1.62 log10 units in sticks prepared from batter at initial fat levels of 15, 20, and 32%, respectively. During storage, the temperature rather than the atmosphere had the greater effect on pathogen numbers, with similar viability observed among the three fat levels tested. At 70°F (ca. 21°C), compared to original levels, pathogen numbers decreased by ≥5.56 and ≥4.53 log10 units within 14 days in slices stored under air and vacuum, respectively, whereas at 39°F (ca. 4°C) numbers decreased by ≤2.43 log10 CFU/g after 60 days of storage under either atmosphere. Baking, as expected, resulted in greater reductions in pathogen numbers as the temperature and/or time of baking increased. However, it was still possible to recover the pathogen by enrichment after baking frozen slices on frozen pizza at 475°F (ca. 246°C) for 10 min or at 375°F (ca. 191°C) for 15 min. The calculated D values for all three temperatures tested increased as the fat content of the batter increased from 15 to 20 to 32%. The present study confirmed that fermentation and drying were sufficient to reduce levels of E. coli O157:H7 in pepperoni sticks by <2.0 log10 CFU/g. Storage of slices for at least 14 days at ambient temperature under air resulted in a >5.5-log10-unit total reduction of the pathogen. Baking slices on frozen pizza for at least 15 min at 475°F (ca. 246°C) or 20 min at 375°F (ca. 191°C) was necessary to reduce pathogen numbers to below detection by both direct plating and enrichment.

Download Full-text