Evaluation of Chlorine Dioxide Gas Treatment To Inactivate Salmonella enterica on Mungbean Sprouts†

Although freshly sprouted beans and grains are considered to be a source of nutrients, they have been associated with foodborne outbreaks. Sprouts provide good matrices for microbial localization and growth due to optimal conditions of temperature and humidity while sprouting. Also, the lack of a kill step postsprouting is a major safety concern. The objective of this work was to evaluate the effectiveness of chlorine dioxide gas treatment to reduce Salmonella on artificially inoculated mungbean sprouts. The effectiveness of gaseous chlorine dioxide (0.5 mg/liter of air) with or without tumbling (mechanical mixing) was compared with an aqueous chlorine (200 ppm) wash treatment. Tumbling the inoculated sprouts during the chlorine dioxide gas application for 15, 30, and 60 min reduced Salmonella populations by 3.0, 4.0, and 5.5 log CFU/g, respectively, as compared with 3.0, 3.0, and 4.0 log CFU/g reductions obtained without tumbling, respectively. A 2.0 log CFU/g reduction in Salmonella was achieved with an aqueous chlorine wash. The difference in microbial reduction between chlorine dioxide gas versus aqueous chlorine wash points to the important role of surface topography, pore structure, bacterial attachment, and/or biofilm formation on sprouts. These data suggested that chlorine dioxide gas was capable of penetrating and inactivating cells that are attached to inaccessible sites and/or are within biofilms on the sprout surface as compared with an aqueous chlorine wash. Consequently, scanning electron microscopy imaging indicated that chlorine dioxide gas treatment was capable of penetrating and inactivating cells attached to inaccessible sites and within biofilms on the sprout surfaces.

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Development of Combined Dry Heat and Chlorine Dioxide Gas Treatment with Mechanical Mixing for Inactivation of Salmonella enterica Serovar Montevideo on Mung Bean Seeds†

Journal of Food Protection ◽

10.4315/0362-028x.jfp-14-422 ◽

2015 ◽

Vol 78 (5) ◽

pp. 868-872 ◽

Cited By ~ 12

Author(s):

BASSAM A. ANNOUS ◽

ANGELA BURKE

Keyword(s):

Chlorine Dioxide ◽

Mung Bean ◽

Safety Concern ◽

Combined Treatment ◽

Hot Water ◽

Mechanical Mixing ◽

Gas Treatment ◽

Chlorine Dioxide Gas ◽

Dry Heat ◽

Complete Inactivation

Foodborne outbreaks have been associated with the consumption of fresh sprouted beans. The sprouting conditions of mung bean seeds provide optimal conditions of temperature and relative humidity for any potential pathogenic contaminant on the seeds to grow. The lack of a kill step postsprouting is a major safety concern. Thus, the use of a kill step on the seeds prior to a sprouting step would enhance the safety of fresh sprouts. The objective of this work was to evaluate the effectiveness of the combined thermal and chlorine dioxide gas (3.5 mg/liter of air) treatment with mechanical mixing (tumbling) to eliminate Salmonella on artificially inoculated mung bean seeds. Although no viable Salmonella was recovered from seeds treated in hot water at 60°C for 2 h, these treated seeds failed to germinate. Dry heat treatments (55, 60, or 70°C) for up to 8 h reduced Salmonella populations in excess of 3 log CFU/g. The use of tumbling, while treating the seeds, resulted in up to 1.6 log CFU/g reduction in Salmonella populations compared with no tumbling. Dry heat treatment at 65°C for 18 h with tumbling resulted in a complete inactivation of Salmonella populations on inoculated seeds with low inoculum levels (2.83 log CFU/g) as compared with high inoculum levels (4.75 log CFU/g). The increased reductions in pathogenic populations on the seeds with the use of tumbling could be attributed to increased uniformity of heat transfer and exposure to chlorine dioxide gas. All treated seeds were capable of germinating, as well as the nontreated controls. These results suggest that this combined treatment would be a viable process for enhancing the safety of fresh sprouts.

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Effect of Chlorine Dioxide Gas Treatment on Surface Sterilization of Grape

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.236-238.2939 ◽

2011 ◽

Vol 236-238 ◽

pp. 2939-2944 ◽

Cited By ~ 1

Author(s):

Ri Ya Jin ◽

Shuang Qi Hu ◽

Zhi Chao Chi

Keyword(s):

Chlorine Dioxide ◽

Treatment Time ◽

Reducing Sugar ◽

Gas Treatment ◽

Surface Sterilization ◽

Log Reduction ◽

Chlorine Dioxide Gas ◽

Spoilage Bacteria ◽

Effect Of Chlorine

Experiments were conducted to investigate the effect of concentration and duration of chlorine dioxide gas treatment on Surface sterilization of grape at 25°C. The results showed that the values of inactivate bacterial log reduction ofBotrytis cinerea,Penicilliumandalternariaincreased with the increasing of ClO2gas concentrations and treatment time. When the concentrations and treatment time was about 10 mg/m3and 30 minutes, respectively, more than 4 log reduction was obtained for the three spoilage bacteria on grape surface. Furthermore, the effect of chlorine dioxide gas treatment on quality of grape was investigated. It was found that the contents of vitamin C (Vc) and reducing sugar (RS) in grape also increased compared with grape without ClO2gas treatment.

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Low-Temperature Decontamination with Hydrogen Peroxide or Chlorine Dioxide for Space Applications

Applied and Environmental Microbiology ◽

10.1128/aem.07948-11 ◽

2012 ◽

Vol 78 (12) ◽

pp. 4169-4174 ◽

Cited By ~ 22

Author(s):

T. Pottage ◽

S. Macken ◽

K. Giri ◽

J. T. Walker ◽

A. M. Bennett

Keyword(s):

Hydrogen Peroxide ◽

Low Temperature ◽

Chlorine Dioxide ◽

Exposure Period ◽

Microbial Reduction ◽

Space Applications ◽

Content Type ◽

Chlorine Dioxide Gas ◽

Dry Heat ◽

D Values

ABSTRACTThe currently used microbial decontamination method for spacecraft and components uses dry-heat microbial reduction at temperatures of >110°C for extended periods to prevent the contamination of extraplanetary destinations. This process is effective and reproducible, but it is also long and costly and precludes the use of heat-labile materials. The need for an alternative to dry-heat microbial reduction has been identified by space agencies. Investigations assessing the biological efficacy of two gaseous decontamination technologies, vapor hydrogen peroxide (Steris) and chlorine dioxide (ClorDiSys), were undertaken in a 20-m3exposure chamber. Five spore-formingBacillusspp. were exposed on stainless steel coupons to vaporized hydrogen peroxide and chlorine dioxide gas. Exposure for 20 min to vapor hydrogen peroxide resulted in 6- and 5-log reductions in the recovery ofBacillus atrophaeusandGeobacillus stearothermophilus, respectively. However, in comparison, chlorine dioxide required an exposure period of 60 min to reduce bothB. atrophaeusandG. stearothermophilusby 5 logs. Of the three otherBacillusspp. tested,Bacillus thuringiensisproved the most resistant to hydrogen peroxide and chlorine dioxide with D values of 175.4 s and 6.6 h, respectively. Both low-temperature decontamination technologies proved effective at reducing theBacillusspp. tested within the exposure ranges by over 5 logs, with the exception ofB. thuringiensis, which was more resistant to both technologies. These results indicate that a review of the indicator organism choice and loading could provide a more appropriate and realistic challenge for the sterilization procedures used in the space industry.

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Microbial reduction field model for the table egg with chlorine dioxide gas

Journal of Preventive Veterinary Medicine ◽

10.13041/jpvm.2020.44.1.33 ◽

2020 ◽

Vol 44 (1) ◽

pp. 33-39

Author(s):

Dong-Hoon Myeong ◽

◽

Han-Sung Chung ◽

Kyoung-Ju Song ◽

Seoung-Jun Kim ◽

...

Keyword(s):

Chlorine Dioxide ◽

Field Model ◽

Microbial Reduction ◽

Chlorine Dioxide Gas

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Chlorine dioxide gas treatment improves the quality of hardy kiwifruit (Actinidia arguta) during storage

Forest Science and Technology ◽

10.1080/21580103.2019.1636414 ◽

2019 ◽

Vol 15 (3) ◽

pp. 159-164

Author(s):

Hyowon Park ◽

Narae Han ◽

Chul-Woo Kim ◽

Uk Lee

Keyword(s):

Chlorine Dioxide ◽

Gas Treatment ◽

Actinidia Arguta ◽

Chlorine Dioxide Gas

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Chloroxyanion Residue Quantification in Cantaloupes Treated with Chlorine Dioxide Gas

Journal of Food Protection ◽

10.4315/0362-028x.jfp-14-576 ◽

2015 ◽

Vol 78 (9) ◽

pp. 1708-1718 ◽

Cited By ~ 12

Author(s):

SIMRAN KAUR ◽

DAVID J. SMITH ◽

MARK. T. MORGAN

Keyword(s):

Chlorine Dioxide ◽

Health Concern ◽

Escherichia Coli O157 ◽

Serum Samples ◽

Gas Generation ◽

Gas Treatment ◽

Log Reduction ◽

Chlorine Dioxide Gas ◽

Fruit Flesh ◽

Mean Concentration

Previous studies show that treatment of cantaloupes with chlorine dioxide (ClO2) gas at 5 mg/liter for 10 min results in a significant reduction (P < 0.05) in initial microflora, an increase in shelf life without any alteration in color, and a 4.6- and 4.3-log reduction of Escherichia coli O157:H7 and Listeria monocytogenes, respectively. However, this treatment could result in the presence of chloroxyanion residues, such as chloride (Cl−), chlorite (ClO2−), chlorate (ClO3−), and perchlorate (ClO4−), which, apart from chloride, are a toxicity concern. Radiolabeled chlorine dioxide (36ClO2) gas was used to describe the identity and distribution of chloroxyanion residues in or on cantaloupe subsequent to fumigation with ClO2 gas at a mean concentration of 5.1 ± 0.7 mg/liter for 10 min. Each treated cantaloupe was separated into rind, flesh, and mixed (rind and flesh) sections, which were blended and centrifuged to give the corresponding sera fractions. Radioactivity detected, ratio of radioactivity to mass of chlorite in initial ClO2 gas generation reaction, and distribution of chloroxyanions in serum samples were used to calculate residue concentrations in flesh, rind, and mixed samples. Anions detected on the cantaloupe were Cl− (~90%) and ClO3− (~10%), located primarily in the rind (19.3 ± 8.0 μg of Cl−/g of rind and 4.8 ± 2.3 μg of ClO3−/g of rind, n = 6). Cantaloupe flesh (~200 g) directly exposed to 36ClO2 gas treatment showed the presence of only Cl− residues (8.1 ± 1.0 μg of Cl−/g of flesh, n = 3). Results indicate chloroxyanion residues Cl− and ClO3− are only present on the rind of whole cantaloupes treated with ClO2 gas. However during cutting, residues may be transferred to the fruit flesh. Because Cl− is not toxic, only ClO3− would be a toxicity concern, but the levels transferred from rind to flesh are very low. In the case of fruit flesh directly exposed to ClO2 gas, only nontoxic Cl− was detected. This indicates that ClO2 gas that comes into contact with edible flesh would not pose a health concern.

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