Efficacy of Chlorine Dioxide Gas as a Sanitizer of Lettuce Leaves

2004 ◽  
Vol 67 (7) ◽  
pp. 1371-1376 ◽  
Author(s):  
SUN-YOUNG LEE ◽  
MICHAEL COSTELLO ◽  
DONG-HYUN KANG
Keyword(s):  
Salmonella Typhimurium ◽  
Chlorine Dioxide ◽  
Foodborne Pathogens ◽  
Fruits And Vegetables ◽  
Hypochlorous Acid ◽  
Disease Outbreaks ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Log Reduction ◽  
Chlorine Dioxide Gas

Aqueous solutions of sodium hypochlorite or hypochlorous acid are typically used to sanitize fresh fruits and vegetables. However, pathogenic organisms occasionally survive aqueous sanitization in sufficient numbers to cause disease outbreaks. Chlorine dioxide (ClO2) gas generated by a dry chemical sachet was tested against foodborne pathogens on lettuce leaves. Lettuce leaves were inoculated with cocktail of three strains each of Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Typhimurium and treated with ClO2 gas for 30 min, 1 h, and 3 h in a model gas cabinet at room temperature (22 ± 2°C). After treatment, surviving cells, including injured cells, were enumerated on appropriate selective agar or using the overlay agar method, respectively. Total ClO2 generated by the gas packs was 4.3, 6.7, and 8.7 mg after 30 min, 1 h, and 3 h of treatment, respectively. Inoculated lettuce leaves exposed to ClO2 gas for 30 min experienced a 3.4-log reduction in E. coli, a 4.3-log reduction in Salmonella Typhimurium, and a 5.0-log reduction in L. monocytogenes when compared with the control. After 1 h, the three pathogens were reduced in number of CFU by 4.4, 5.3, and 5.2 log, respectively. After 3 h, the reductions were 6.9, 5.4, and 5.4 log, respectively. A similar pattern emerged when injured cells were enumerated. The ClO2 gas sachet was effective at killing pathogens on lettuce without deteriorating visual quality. Therefore, this product can be used during storage and transport of lettuce to improve its microbial safety.

Development of sustained release formulations of chlorine dioxide gas for inactivation of foodborne pathogens on produce

2021 ◽  
pp. 108201322097628
Author(s):  
Sang-Hyun Park ◽  
Sang-Soon Kim ◽  
Dong-Hyun Kang
Keyword(s):  
Sustained Release ◽  
Chlorine Dioxide ◽  
Foodborne Pathogens ◽  
Food Industry ◽  
Sodium Chlorite ◽  
Escherichia Coli O157 ◽  
Gas Concentration ◽  
E Coli ◽  
Chlorine Dioxide Gas ◽  
Spinach Leaves

Formulations for the sustained release of chlorine dioxide (ClO2) gas were developed, and their gas-producing profiles and antimicrobial effects against Escherichia coli O157:H7 and Salmonella Typhimurium were evaluated in spinach leaves and tomatoes under different relative humidity (RH) conditions. Sodium chlorite (NaClO2) and citric acid were used to generate ClO2 gas, and the generation rate and maximum ClO2 gas concentration were controlled using diatomaceous earth (DE) and calcium chloride (CaCl2). Under 90% RH conditions, sustained release of ClO2 gas was achieved in presence of DE. When 12 g of DE was added to the mixture, the ClO2 gas concentration remained constant at 18 ± 1 ppmv for approximately 28 h. At 50% RH, addition of CaCl2 was effective in maintaining a constant ClO2 gas concentration. When 0.05 g of CaCl2 was added to mixtures containing 0.5 g of DE, ClO2 gas concentration remained constant at 11 ± 1 ppmv for approximately 26 h. Treatment with 30 ppmv of ClO2 gas at 90% RH achieved more than 6.16 and 5.48 log reductions of E. coli O157:H7 and S. Typhimurium on spinach leaves (in 15 min), and more than 6.78 and 6.34 log reductions of the same in tomatoes (in 10 min). The sustained release formulations for ClO2 gas, developed in this study, could facilitate the use of ClO2 gas as an antimicrobial agent in the food industry.

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

2000 ◽  
Vol 63 (6) ◽  
pp. 703-708 ◽  
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.

Antagonistic Action of Cells of Lactobacillus delbrueckii subsp. lactis against Pathogenic and Spoilage Microorganisms in Fresh Meat Systems†

2003 ◽  
Vol 66 (3) ◽  
pp. 418-425 ◽  
Author(s):  
M. M. SENNE ◽  
S. E. GILLILAND
Keyword(s):  
Salmonella Typhimurium ◽  
Foodborne Pathogens ◽  
Lactobacillus Delbrueckii ◽  
Model Systems ◽  
Escherichia Coli O157 ◽  
Fresh Meat ◽  
Antagonistic Action ◽  
E Coli ◽  
Spoilage Microorganisms ◽  
Lactobacillus Delbrueckii Subsp

Cells of Lactobacillus delbrueckii subsp. lactis RM2-5 were added to various meat model systems that had been inoculated with Escherichia coli O157:H7 or Salmonella Typhimurium to determine whether these lactobacilli were antagonistic to the pathogens during storage at 5°C. Experiments in which L. delbrueckii subsp. lactis RM2-5 was directly applied to the surfaces of beefsteaks resulted in significant (P < 0.05) reductions in the growth of psychrotrophs and coliforms plus a slight decrease in the numbers of E. coli O157:H7 over time relative to those for control samples to which no lactobacilli had been added. Experiments involving the direct application of L. delbrueckii subsp. lactis RM2-5 to the surfaces of freshly slaughtered beef and pork carcass samples inoculated with either E. coli O157:H7 or Salmonella Typhimurium showed significant (P < 0.05) declines in numbers of the pathogens as well as a reduction in the growth of psychrotrophs during storage at 5°C for 6 days. The results of the experiments suggest that lactobacillus cultures have potential for use in an intervention technology for the control of foodborne pathogens, especially on the surfaces of beef and pork carcasses. The results of this study also suggest that an extension of the shelf life of meat can result from the decreased growth of psychrotrophic spoilage organisms.

Inactivation of Pathogenic Bacteria by Cucumber Volatiles (E,Z)-2,6-Nonadienal and (E)-2-Nonenal†

2004 ◽  
Vol 67 (5) ◽  
pp. 1014-1016 ◽  
Author(s):  
M. J. CHO ◽  
R. W. BUESCHER ◽  
M. JOHNSON ◽  
M. JANES
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Salmonella Typhimurium ◽  
Bactericidal Activity ◽  
Pathogenic Bacteria ◽  
Brain Heart Infusion ◽  
Escherichia Coli O157 ◽  
Infusion Solution ◽  
E Coli ◽  
Log Reduction

The effects of (E,Z)-2,6-nonadienal (NDE) and (E)-2-nonenal (NE) on Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Typhimurium were investigated. A suspension of each organism of 6 to 9 log CFU/ml was incubated for 1 h at 37° C in brain heart infusion solution that contained 0 to 500 or 1,000 ppm of NDE or NE. Depending on concentration, exposure to either NDE or NE caused a reduction in CFU of each organism. Treatment with 250 and 500 ppm NDE completely eliminated viable B. cereus and Salmonella Typhimurium cells, respectively. L. monocytogenes was the most resistant to NDE, showing only about a 2-log reduction from exposure to 500 ppm for 1 h. Conversely, this concentration of NDE caused a 5.8-log reduction in E. coli O157:H7 cells. NE was also effective in inactivating organisms listed above. A higher concentration of NE, 1,000 ppm, was required to kill E. coli O157:H7, L. monocytogenes, or Salmonella Typhimurium compared with NDE. In conclusion, both NDE and NE demonstrated an apparent bactericidal activity against these pathogens.

Validation of the Use of Organic Acids and Acidified Sodium Chlorite To Reduce Escherichia coli O157 and Salmonella Typhimurium in Beef Trim and Ground Beef in a Simulated Processing Environment

2006 ◽  
Vol 69 (8) ◽  
pp. 1802-1807 ◽  
Author(s):  
K. HARRIS ◽  
M. F. MILLER ◽  
G. H. LONERAGAN ◽  
M. M. BRASHEARS
Keyword(s):  
Escherichia Coli ◽  
Salmonella Typhimurium ◽  
Frozen Storage ◽  
Ground Beef ◽  
Sodium Chlorite ◽  
Escherichia Coli O157 ◽  
Refrigerated Storage ◽  
E Coli ◽  
Log Reduction ◽  
Antimicrobial Treatments

A study was conducted to determine if acidified sodium chlorite (1,200 ppm) and acetic and lactic acids (2 and 4%) were effective in reducing foodborne pathogens in beef trim prior to grinding in a simulated processing environment. The reduction of Salmonella Typhimurium and Escherichia coli O157:H7 at high (4.0 log CFU/g) and low (1.0 log CFU/g) inoculation doses was evaluated at various processing steps, including the following: (i) in trim just after treatment application, (ii) in ground beef just after grinding, (iii) in ground beef 24 h after refrigerated storage, (iv) in ground beef 5 days after refrigerated storage, and (v) in ground beef 30 days after frozen storage. All antimicrobial treatments reduced the pathogens on the trim inoculated with the lower inoculation dose to nondetectable numbers in the trim and in the ground beef. There were significant reductions of both pathogens in the trim and in the ground beef inoculated with the high inoculation doses. On the trim itself, E. coli O157:H7 and Salmonella Typhimurium were reduced by 1.5 to 2.0 log cycles, with no differences among all treatments. In the ground beef, the organic acids were more effective in reducing both pathogens than the acidified sodium chlorite immediately after grinding, but after 1 day of storage, there were no differences among treatments. Overall, in the ground beef, there was a 2.5-log reduction of E. coli O157:H7 and a 1.5-log reduction of Salmonella Typhimurium that was sustained over time in refrigerated and frozen storage. Very few sensory differences between the control samples and the treated samples were detected by a consumer panel. Thus, antimicrobial treatments did not cause serious adverse sensory changes. Use of these antimicrobial treatments can be a promising intervention available to ground beef processors who currently have few interventions in their process.

Response Surface Modeling for the Inactivation of Escherichia coli O157:H7 on Green Peppers (Capsicum annuum L.) by Chlorine Dioxide Gas Treatments†

2001 ◽  
Vol 64 (8) ◽  
pp. 1128-1133 ◽  
Author(s):  
Y. HAN ◽  
J. D. FLOROS ◽  
R. H. LINTON ◽  
S. S. NIELSEN ◽  
P. E. NELSON
Keyword(s):  
Escherichia Coli ◽  
Predictive Model ◽  
Response Surface ◽  
Chlorine Dioxide ◽  
Treatment Time ◽  
Membrane Surface ◽  
Escherichia Coli O157 ◽  
Gas Concentration ◽  
E Coli ◽  
Log Reduction

The effects of chlorine dioxide (ClO2) gas concentration (0.1 to 0.5 mg/liter), relative humidity (RH) (55 to 95%), treatment time (7 to 135 min), and temperature (5 to 25°C) on inactivation of Escherichia coli O157:H7 on green peppers were studied using response surface methods. A four-factor, central, composite, rotatable design was used. The microbial log reduction was measured as a response. A direct membrane-surface-plating method with tryptic soy agar and sorbitol Mac-Conkey agar was used to resuscitate and enumerate ClO2-treated E. coli O157:H7 cells. The statistical analysis and the predictive model developed in this study suggest that ClO2 gas concentration, treatment time, RH, and temperature all significantly (P < 0.01) increased the inactivation of E. coli O157:H7. ClO2 gas concentration was the most important factor, whereas temperature was the least significant. The interaction between ClO2 gas concentration and RH indicated a synergistic effect. The predictive model was validated, and it could be used to determine effective ClO2 gas treatments to achieve a 5-log reduction of E. coli O157:H7 on green peppers.

Reduction of Escherichia coli O157:H7 on Produce by Use of Electrolyzed Water under Simulated Food Service Operation Conditions

2009 ◽  
Vol 72 (9) ◽  
pp. 1854-1861 ◽  
Author(s):  
PHILIPUS PANGLOLI ◽  
YEN-CON HUNG ◽  
LARRY R. BEUCHAT ◽  
C. HAROLD KING ◽  
ZHI-HUI ZHAO
Keyword(s):  
Escherichia Coli ◽  
Foodborne Pathogens ◽  
Fruits And Vegetables ◽  
Tap Water ◽  
Food Service ◽  
Escherichia Coli O157 ◽  
Electrolyzed Water ◽  
E Coli ◽  
Operation Conditions ◽  
Iceberg Lettuce

Treatment of fresh fruits and vegetables with electrolyzed water (EW) has been shown to kill or reduce foodborne pathogens. We evaluated the efficacy of EW in killing Escherichia coli O157:H7 on iceberg lettuce, cabbage, lemons, and tomatoes by using washing and/or chilling treatments simulating those followed in some food service kitchens. Greatest reduction levels on lettuce were achieved by sequentially washing with 14-A (amperage) acidic EW (AcEW) for 15 or 30 s followed by chilling in 16-A AcEW for 15 min. This procedure reduced the pathogen by 2.8 and 3.0 log CFU per leaf, respectively, whereas washing and chilling with tap water reduced the pathogen by 1.9 and 2.4 log CFU per leaf. Washing cabbage leaves for 15 or 30 s with tap water or 14-A AcEW reduced the pathogen by 2.0 and 3.0 log CFU per leaf and 2.5 to 3.0 log CFU per leaf, respectively. The pathogen was reduced by 4.7 log CFU per lemon by washing with 14-A AcEW and 4.1 and 4.5 log CFU per lemon by washing with tap water for 15 or 30 s. A reduction of 5.3 log CFU per lemon was achieved by washing with 14-A alkaline EW for 15 s prior to washing with 14-A AcEW for 15 s. Washing tomatoes with tap water or 14-A AcEW for 15 s reduced the pathogen by 6.4 and 7.9 log CFU per tomato, respectively. Application of AcEW using procedures mimicking food service operations should help minimize cross-contamination and reduce the risk of E. coli O157:H7 being present on produce at the time of consumption.

Efficacy of Aerosolized Peroxyacetic Acid as a Sanitizer of Lettuce Leaves

2005 ◽  
Vol 68 (8) ◽  
pp. 1743-1747 ◽  
Author(s):  
SE-WOOK OH ◽  
GENISIS IRIS DANCER ◽  
DONG-HYUN KANG
Keyword(s):  
Salmonella Typhimurium ◽  
Particle Diameter ◽  
Escherichia Coli O157 ◽  
Bacterial Cells ◽  
Peroxyacetic Acid ◽  
E Coli ◽  
Log Reduction ◽  
Iceberg Lettuce ◽  
Model Aerosol ◽  
Potential Alternative

Aerosolized sanitizer was investigated as a potential alternative to aqueous and gaseous sanitizers for produce. Peroxyacetic acid was aerosolized (5.42 to 11.42 μm particle diameter) by a commercially available nebulizer into a model cabinet. Iceberg lettuce leaves were inoculated with three strains each of Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Typhimurium and then treated with aerosolized peroxyacetic acid for 10, 30, or 60 min in a model aerosol cabinet at room temperature (22 ± 2°C). After treatment, surviving healthy and injured bacterial cells were enumerated on appropriate selective agars or using the overlay agar method. Inoculated iceberg lettuce leaves exposed to aerosolized peroxyacetic acid for 10 min exhibited a 0.8-log reduction in E. coli O157:H7, a 0.3-log reduction in Salmonella Typhimurium, and a 2.5-log reduction in L. monocytogenes when compared with the control. After 30 min of treatment, the three pathogens were reduced by 2.2, 3.3, and 2.7 log, and after 60 min, the reductions were 3.4, 4.5, and 3.8 log, respectively. Aerosolization may be a new and convenient method for sanitizing produce for storage or shipping.

Fate of Listeria monocytogenes, Salmonella Typhimurium DT104, and Escherichia coli O157:H7 in Labneh as a Pre- and Postfermentation Contaminant

2000 ◽  
Vol 63 (5) ◽  
pp. 608-612 ◽  
Author(s):  
MOHSEN S. ISSA ◽  
ELLIOT T. RYSER
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Salmonella Typhimurium ◽  
Foodborne Pathogens ◽  
Storage Temperature ◽  
Starter Culture ◽  
Salt Content ◽  
Health Concern ◽  
Escherichia Coli O157 ◽  
E Coli

Commercially pasteurized milk (∼2% milkfat) was heated at 85 to 87°C/30 min, inoculated to contain 2,000 to 6,000 CFU/ml of Listeria monocytogenes, Salmonella Typhimurium DT104, or Escherichia coli O157:H7, cultured at 43°C for 4 h with a 2.0% (wt/wt) commercial yogurt starter culture, stored 12 to 14 h at 6°C, and centrifuged to obtain a Labneh-like product. Alternatively, traditional salted and unsalted Labneh was prepared using a 3.0% (wt/wt) starter culture inoculum, similarly inoculated after manufacture with the aforementioned pathogens, and stored at 6°C and 20°C. Throughout fermentation, Listeria populations remained unchanged, whereas numbers of Salmonella increased 0.33 to 0.47 logs during the first 2 h of fermentation and decreased thereafter. E. coli populations increased 0.46 to 1.19 logs during fermentation and remained that these levels during overnight cold storage. When unsalted and salted Labneh were inoculated after manufacture, Salmonella populations decreased >2 logs in all samples after 2 days, regardless of storage temperature, with the pathogen no longer detected in 4-day-old samples. Numbers of L. monocytogenes decreased from 2.48 to 3.70 to <1.00 to 1.95 logs after 2 days with the pathogen persisting up to 15 days in one lot of salted/unsalted Labneh stored at 6°C. E. coli O157:H7 populations decreased from 3.39 to 3.7 to <1.00 to 2.08 logs during the first 2 days, with the pathogen no longer detected in any 4-dayold samples. Inactivation rates for all three pathogens in Labneh were unrelated to storage temperature or salt content. Unlike L. monocytogenes that persisted up to 15 days in Labneh, rapid inactivation of Salmonella Typhimurium DT104 and E. coli O157:H7 suggests that these emerging foodborne pathogens are of less public health concern in traditional Labneh.

Growth and Survival of Foodborne Pathogens in Beer

2011 ◽  
Vol 74 (10) ◽  
pp. 1670-1675 ◽  
Author(s):  
GARRY MENZ ◽  
PETER ALDRED ◽  
FRANK VRIESEKOOP
Keyword(s):  
Salmonella Typhimurium ◽  
Foodborne Pathogens ◽  
Storage Temperature ◽  
Escherichia Coli O157 ◽  
Gram Negative ◽  
Growth And Survival ◽  
E Coli ◽  
And Storage ◽  
And Staphylococcus Aureus ◽  
Storage Temperatures

This work aimed to assess the growth and survival of four foodborne pathogens (Escherichia coli O157:H7, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus) in beer. The effects of ethanol, pH, and storage temperature were investigated for the gram-negative pathogens (E. coli O157:H7 and Salmonella Typhimurium), whereas the presence of hops ensured that the gram-positive pathogens (L. monocytogenes and S. aureus) were rapidly inactivated in alcohol-free beer. The pathogens E. coli O157:H7 and Salmonella Typhimurium could not grow in the mid-strength or full-strength beers, although they could survive for more than 30 days in the mid-strength beer when held at 4°C. These pathogens grew rapidly in the alcohol-free beer; however, growth was prevented when the pH of the alcohol-free beer was lowered from the “as received” value of 4.3 to 4.0. Pathogen survival in all beers was prolonged at lowered storage temperatures.

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