In Situ Generation of Chlorine Dioxide for Surface Decontamination of Produce

2017 ◽  
Vol 80 (4) ◽  
pp. 567-572 ◽  
Author(s):  
Cheng-An Hwang ◽  
Lihan Huang ◽  
Vivian Chi-Hua Wu
Keyword(s):  
Chlorine Dioxide ◽  
Foodborne Pathogens ◽  
Fruits And Vegetables ◽  
Sequential Treatment ◽  
Sodium Chlorite ◽  
Plant Tissues ◽  
Foodborne Illnesses ◽  
Surface Decontamination ◽  
Unique Surface

ABSTRACT Fresh fruits and vegetables are frequently contaminated with bacterial pathogens and implicated in foodborne illnesses. The objective of this study was to develop a unique surface decontamination method for produce using sodium chlorite and an acid in a sequential treatment. The surfaces of cantaloupe rinds, peels of cucumbers, stem scars of grape tomatoes, and leaves of baby spinach were inoculated with Salmonella or Listeria monocytogenes at 5 to 6 log CFU/g, submerged in 1.6 to 4% sodium chlorite solutions for 10 or 30 min, dried for 20 min, and then soaked in 6 mM hydrogen chloride (HCl) for 10 or 30 min and dried for 20 min. Control samples were treated with deionized water, sodium chlorite, HCl, or a premixed solution of sodium chlorite and HCl for comparison. The control treatments reduced the levels of both pathogens on the samples by only 0.3 to 2.9 log CFU/g, whereas the sequential treatment caused significantly higher reductions (P < 0.05) of 5.1 to 5.6 log CFU/g, effectively eliminating the inoculated pathogens. The more effective decontamination resulting from the sequential treatment was attributed to the in situ formation of chlorine dioxide within the plant tissues under the surface by the reaction between sodium chlorite absorbed by the produce and HCl. These results suggest that the sequential use of sodium chlorite and acid is a potentially effective treatment for elimination of foodborne pathogens on produce.

In Situ Generation of Chlorine Dioxide for Decontamination of Salmonella, Listeria monocytogenes, and Pathogenic Escherichia coli on Cantaloupes, Mung Beans, and Alfalfa Seeds

2020 ◽  
Vol 83 (2) ◽  
pp. 287-294
Author(s):  
JING NI TAN ◽  
CHENG-AN HWANG ◽  
LIHAN HUANG ◽  
VIVIAN C. H. WU ◽  
HSIN-I HSIAO
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Chlorine Dioxide ◽  
Sequential Treatment ◽  
Sodium Chlorite ◽  
In Situ Generation ◽  
The Individual ◽  
Pathogen Populations ◽  
Alfalfa Seeds

ABSTRACT In situ generation of chlorine dioxide to reduce microbial populations on produce surfaces has been shown to be effective on produce models. This study examined the treatment for decontamination of bacterial pathogens on whole cantaloupes and sprout seeds. Whole cantaloupes, mung beans, and alfalfa seeds were inoculated with Salmonella, Listeria monocytogenes, and Shiga toxin–producing Escherichia coli, sprayed with or dipped in 0.4 to 1.6% sodium chlorite (NaClO2) solutions, dried, and treated with 6 mM hydrochloric acid (HCl; sequential treatment). Controls were samples treated with NaClO2 or HCl (individual treatment). The pathogen populations on samples before and after treatments were enumerated to determine the reductions of pathogen populations by the treatments. The methods of applying NaClO2 and HCl (dipping for 30 min or spraying 0.2 g on cantaloupe rind [2 by 2 cm]), NaClO2 concentrations of 0.4 to 1.6% for cantaloupes, and treatment times of 5, 15, and 30 min for sprout seeds were evaluated to identify treatment parameters. For cantaloupes treated with spraying with 1.6% NaClO2, the sequential treatment caused significantly (P < 0.05) higher reductions (6.2 to 7.7 log CFU/cm2) than the combined reductions (3.2 to 5.2 log CFU/cm2) by the individual treatments. For cantaloupes treated by dipping in 1.6% NaClO2 and by spraying with 0.4 and 0.8% NaClO2, the reductions caused by the sequential treatment were not significantly (P > 0.05) different from those by the individual treatments. For mung beans, sequential 15- and 30-min treatments caused significantly (P < 0.05) higher reductions of 4.3 to 5.0 and 4.7 to 6.7 log CFU/g, respectively, than the individual treatments. The sequential 15-min treatment also caused high reductions of 5.1 to 7.3 log CFU/g on alfalfa seeds. The treatments did not bleach the color of cantaloupes and did not affect the germination rates of mung beans and alfalfa seeds. This study identified 1.6% NaClO2 and 6 mM HCl for sequential spraying treatment for cantaloupes and for sequential dipping (15-min) treatment for mung beans and alfalfa seeds that may be used for decontamination of whole cantaloupes and sprout seeds. HIGHLIGHTS

scholarly journals Efficacy of Bacteriophage Cocktail to Control E. coli O157:H7 Contamination on Baby Spinach Leaves in the Presence or Absence of Organic Load

2021 ◽  
Vol 9 (3) ◽  
pp. 544
Author(s):  
Badrinath Vengarai Jagannathan ◽  
Steven Kitchens ◽  
Paul Priyesh Vijayakumar ◽  
Stuart Price ◽  
Melissa Morgan
Keyword(s):  
Foodborne Pathogens ◽  
Fruits And Vegetables ◽  
Healthy Lifestyle ◽  
Foodborne Pathogen ◽  
Organic Load ◽  
Lytic Bacteriophage ◽  
Foodborne Illnesses ◽  
E Coli ◽  
Pathogen Reduction ◽  
Spinach Leaves

Fruits and vegetables are high in nutrients that are essential for a healthy lifestyle. However, they also harbor an extensive array of microorganisms such as bacteria, which can be beneficial, neutral, or pathogenic. Foodborne pathogens can contaminate produce at any stage from the farm to the consumer’s table. Appropriate washing techniques using sanitizers can reduce the risk of pathogen contamination. Issues related to maintaining concentration, efficacy, and other problems have been a challenge for the food industry and, when left unresolved, have led to different outbreaks of foodborne illnesses. In this study, the efficacy of a lytic bacteriophage cocktail was examined for its ability to infect and reduce the contamination of Escherichia coli O157:H7 (E. coli O157:H7), in media with a high organic load, using a microplate technique. The study was conducted for 3 h to determine if the bacteriophage cocktail could reduce the pathogen in the presence of a high organic load. A significant (p < 0.05) reduction in the population of E. coli O157:H7 was observed, representing a 99.99% pathogen reduction at the end of 3 h. Fresh spinach leaves were washed in sterile potable or organic water (~9000 ppm organic load) containing E. coli O157:H7 and a bacteriophage cocktail to study the effectiveness of bacteriophages against the foodborne pathogen. Results indicated that the bacteriophage significantly (p < 0.05) reduced the contamination of E. coli O157:H7 in both situations. The study also demonstrated the bacteriophages’ ability to infect and reduce the pathogen in an organic-rich environment. This characteristic differs from commercially available sanitizers that have demonstrated a tendency to bind with the available organic load. Thus, these studies highlight the advantage of employing bacteriophages during produce wash to eliminate foodborne pathogen contamination on fruits and vegetables.

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.

Understanding the Role of Chlorine and Ozone to Control Postharvest Diseases in Fruit and Vegetables: A Review

2020 ◽  
Vol 16 (4) ◽  
pp. 455-461
Author(s):  
Gabriela M. Baia ◽  
Otniel Freitas-Silva ◽  
Murillo F. Junior
Keyword(s):  
Chlorine Dioxide ◽  
Broad Spectrum ◽  
Fruits And Vegetables ◽  
Low Cost ◽  
Residual Effects ◽  
Pathogenic Microorganisms ◽  
Postharvest Diseases ◽  
Post Harvest ◽  
By Products

Fruits and vegetables are foods that come into contact with various types of microorganisms from planting to their consumption. A lack or poor sanitation of these products after harvest can cause high losses due to deterioration and/ or pathogenic microorganisms. There are practically no post-harvest fungicides or bactericides with a broad spectrum of action that have no toxic residual effects and are safe. However, to minimize such problems, the use of sanitizers is an efficient device against these microorganisms. Chlorine is the most prevalent sanitizing agent because of its broad spectrum, low cost and well-established practices. However, the inevitable formation of disinfection by-products, such as trihalomethanes (THMs) and haloacetic acids (HAAs), is considered one of the main threats to food safety. Alternative sanitizers, such as chlorine dioxide (ClO2) and ozone, are becoming popular as a substitute for traditional post-harvest treatments. Thus, this review addresses the use of chlorine, chlorine dioxide and ozone emphasizing aspects, such as usage, safe application, spectrum of action and legislation. In order to ensure the quality and safety of final products, the adoption of well-prepared sanitation and sanitation programs for post-harvest fruits and vegetables is essential.

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