Chlorine Dioxide Gas Treatment Research Articles

Mild heating and ambient storage following gaseous chlorine dioxide treatment of chia seeds enhanced inactivation of Salmonella spp.

Chlorine dioxide (ClO2) gas is widely recognized as a potent antimicrobial agent effective against various microorganisms. Chia seeds are prone to microbial contamination, and thermal treatments are not feasible due to potential quality issues. The study is aimed at investigating the effectiveness of chlorine dioxide (ClO2) gas followed by mild heat for Salmonella reduction in chia seeds. Chia seeds were inoculated with a five-strain Salmonella cocktail and treated for 2 h at two conditions – 5 mg/L gas concentration at 80% RH and 3 mg/L at 90% RH. The samples subjected to ClO2 were mild heat treated at 40 and 60 °C for either 1 or 2 h, and Salmonella reduction is determined during one month of ambient storage. At 80% RH, ClO2 resulted in a 1.80 log reduction of Salmonella while a significantly (p < 0.05) higher log reduction of 2.82 log CFU/g was achieved at 90% RH. Subsequent mild heat treatment at 60 °C for 2 h resulted in additional log reductions of 1.14 and 1.32 for 80% and 90% RH. During the storage study, it was observed that the Salmonella population continued to decline over time. After 7 days of storage, samples treated with ClO2 at 80% and 90% RH without the application of mild heating, provided a cumulative log reduction of 2.87 and 3.81 after 7 days of storage. ClO2 treatment (3 mg/L at 90% RH) followed by mild heating (60 °C for 2 h) and 7 days of storage achieved close to 5 log reduction. The quality of chia seeds was minimally affected by ClO2 treatment, both alone and in combination with mild heating, as indicated by the insignificant changes in color values, fatty acids, and phenolic content, germination ability, and byproduct residues. This study demonstrates the effectiveness of post ClO2 mild heating and subsequent storage to enhance the microbiological safety of chia seeds.

Inactivation Kinetics of Escherichia coli O157:H7 on Baby-Cut Carrots During Gaseous Chlorine Dioxide Treatment: The Impact of Relative Humidity

Inactivation Kinetics of Escherichia coli O157:H7 on Baby-Cut Carrots During Gaseous Chlorine Dioxide Treatment: The Impact of Relative Humidity

Effect of storage on microbial reductions after gaseous chlorine dioxide treatment of black peppercorns, cumin seeds, and dried basil leaves

Effect of storage on microbial reductions after gaseous chlorine dioxide treatment of black peppercorns, cumin seeds, and dried basil leaves

Evaluation of wheat kernel and flour quality as influenced by chlorine dioxide gas treatment

Chlorine dioxide (ClO2) gas, known for its high oxidation and penetration capacity, is a potential alternative fumigant to control stored-product insect pest population. In this study, hard red spring wheat (Triticum aestivum L.) kernels were exposed to varying levels of gaseous ClO2 concentrations (200, 300, 400, and 500 ppm, 1 ppm = 0.0027 mg/L at room condition) and held in a gas-tight bucket assembly for 24 h after achieving desired concentration. ClO2 treatment achieved complete insect mortality of lesser grain borer (Rhyzopertha dominica (Fabricius)) and highest adult progeny reduction at 500 ppm across all vial locations. Significant reduction (37.8–51.1%) in germination percentage resulted after exposure to 300–500 ppm. Flour lightness value significantly increased after kernel treatment at 200–500 ppm. The pH value of wheat flour was significantly reduced from 6.2 to 6.1 after 500 ppm treatment. Peak and final viscosities of wheat flour significantly decreased from 3303.7 to 3073.3 cP, and from 3515.0 to 3208.3 cP, respectively. No significant difference was observed in other investigated flour quality and functionality parameters, including falling number, trough viscosity, breakdown viscosity, starch damage, and Mixolab dough behavior properties. Overall, ClO2 treatment at 500 ppm is effective in killing adult lesser grain borers without negatively affecting wheat flour quality parameters.

Lipid Oxidation and Volatile Compounds of Almonds as Affected by Gaseous Chlorine Dioxide Treatment to Reduce Salmonella Populations.

The effects of gaseous chlorine dioxide (ClO2) treatment, applied to inactivate Salmonella, on lipid oxidation, volatile compounds, and chlorate levels of dehulled almonds were evaluated during a 3 month accelerated storage at 39 °C. At treatment levels that yielded a 2.91 log reduction of Salmonella, ClO2 promoted lipid oxidation as indicated by increased peroxide values, total acid number, conjugated dienes, and thiobarbituric acid-reactive substances. Furthermore, several chlorine-containing volatile compounds including trichloromethane, 1-chloro-2-propanol, 1,1,1-trichloro-2-propanol, and 1,3-dichloro-2-propanol were identified in ClO2-treated samples. However, all the volatile chlorine-containing compounds decreased during the 3 months of storage. Chlorate (26.4 ± 5.1 μg/g) was found on the ClO2-treated samples. The amounts of non-ethanol alcohols, aldehydes, and carboxylic acids increased following ClO2 treatments. Some volatiles such as 2,3-butanediol that were present in non-treated samples became non-detectable during post-ClO2 treatment storage. Overall, our results demonstrated that gaseous ClO2 treatment promoted lipid oxidation, generation of volatiles of lipid origin, and several chlorine-containing compounds.

Novel gaseous chlorine dioxide treatment system for improving the safety and quality of table grapes during cold storage

This study focused on the development of a gaseous ClO2 treatment system that contained dry ice that was used to form carbon dioxide (CO2) and an absorbent pad with sodium chlorite (NaClO2) solution for ClO2 gas generation. Furthermore, the effects of ClO2 gas on the populations of Listeria monocytogenes and the quality properties of table grapes during cold storage were evaluated. The system continuously released the sufficient concentrations of ClO2 gas to treat berries during 30 d of cold storage. After 20 h of ClO2 gas treatment, the populations of Listeria monocytogenes decreased from 5.88 log CFU/g to a non-detectable (ND) level. There were no significant (p > 0.05) changes in the color parameters (L*, a*, and b*) of table grapes treated with ClO2 gas. The firmness, weight, total soluble solids (TSS), and titratable acid (TA) losses of table grapes were significantly (p < 0.05) reduced by ClO2 gas, while Vitamin C was unaffected. Additionally, the residual ClO2 of table grapes were <0.5 mg/kg, which is considered a safe level. Overall, the novel gaseous ClO2 treatment system may be used as an effective intervention technology to improve the safety and quality of table grapes during cold storage.

Effect of Gaseous Chlorine Dioxide Treatment on the Quality Characteristics of Buckwheat-Based Composite Flour and Storage Stability of Fresh Noodles

In this study, the effects of gaseous chlorine dioxide treatment on the physicochemical properties of buckwheat-based composited flour (buckwheat-wheat-gluten) and shelf-life of fresh buckwheat noodles (FBNs), as well as the textural qualities and sensory properties of noodles were investigated. Chlorine dioxide treatment significantly reduced the total plate count (TPC) and the total flavonoids content in the mixed flour (p &lt; 0.05), but the whiteness, development time and stability time were all increased. During storage, the microbial growth and darkening rate of FBNs made from chlorine dioxide treated buckwheat-based composite flour (CDBF) were delayed significantly, slowing the deterioration and improving storage stability of buckwheat noodles. In addition, chlorine dioxide treatment had no apparent adverse effect on the cooking loss and sensory characteristics during noodle storage. This finding would provide a new concept for the production of “low bacterial buckwheat-based flour” and have important consequences for the application of gaseous chlorine dioxide in food industry.

Microbial Inhibition Test of Sustained-Release Chlorine Dioxide Gas Freshness Retaining Agent

Currently, most of the chlorine dioxide gas is processed at the beginning of storage or distribution. It has the disadvantage of not being able to continuously process gas since there is no system that can continuously process it during the distribution process. Therefore, in order to minimize changes in freshness and quality during the distribution process of agrifood, there is a need for a sustained-release chlorine dioxide gas treatment technology that can be continuously released. Therefore, in this study, the film to be used was examined so that the chlorine dioxide gas can be continuously released for a certain period of time, the concentration of the reactant and the viscosity at the time of the reaction were determined, and a chlorine dioxide gas gel pack was manufactured using this optimal condition. In addition, the gel pack was used to measure the amount of chlorine dioxide gas released and the sterilization effect of food poisoning bacteria.

Gaseous Chlorine Dioxide Treatment Suppresses Decay and Microbial Growth in Cold-stored Jujube Fruit

Gaseous Chlorine Dioxide Treatment Suppresses Decay and Microbial Growth in Cold-stored Jujube Fruit

Effects of Low-Temperature Drying with Intermittent Gaseous Chlorine Dioxide Treatment on Texture and Shelf-Life of Rice Cakes

We investigated the effect of chlorine dioxide (ClO2) under low temperature drying to suppress rice cake stickiness during the cutting process by initiating the onset of retrogradation until the stickiness is minimized for shelf-life extension. The intermittent ClO2 application at low-temperature drying was conducted at 10 °C for different drying periods (0, 6, 12, 18, and 24 h). Texture analysis showed significant differences with increasing values of hardness (901.39 ± 53.87 to 12,653 ± 1689.35 g) and reduced values of modified adhesiveness (3614.37 ±578.23 to 534.81 ± 89.37 g). The evaluation of rice cake stickiness during the cutting process revealed an optimum drying period of 18 h with no significant difference (p ≤ 0.05) compared to the 24 h drying process. Microbial contamination during the drying process increased, with microbial load from 6.39 ± 0.37 to 7.94 ± 0.29 CFU/g. Intermittent ClO2 application at 22 ppm successfully reduced the microbial load by 63% during drying process. The inhibitory property of ClO2 was further analyzed on a sample with high initial microbial load (3.01 ± 0.14 CFU/g) using primary and modified secondary growth models fitted to all experimental storage temperatures (5–25 °C) with R2 values &gt; 0.99. The model demonstrated a strong inhibition by ClO2 with microbial growth not exceeding the accepted population threshold (106 CFU/g) for toxin production. The shelf-life of rice cake was increased by 86 h and 432 h at room temperature (25 °C) and 5 °C respectively. Microbial inactivation via ClO2 treatment is a novel method for improved food storage without additional thermal sterilization or the use of an additional processing unit.

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

The effects of gaseous chlorine dioxide fumigation treatment on the quality of Actinidia arguta “Daebo,” a hardy kiwifruit, were investigated. Hardy kiwifruit was fumigated with 30 mg L−1 chlorine dioxide gas for 30 min and stored at 2 °C for 5 weeks. Fruit firmness rapidly decreased the first 2 weeks of storage after fumigation, whereas the content of soluble solids increased. However, the firmness of chlorine dioxide-treated fruits was significantly higher than that of control fruits after 2 weeks of storage, indicating that the treatment helped to maintain the firmness of hardy kiwifruit. The changes in soluble solids content and titratable acidity during storage suggested that the ripening process of the hardy kiwifruit was delayed in gas-treated fruit. Moreover, chlorine dioxide gas treatment reduced the decay incidence and population of microorganisms on fruit surface. These results suggest that treatment with gaseous chlorine dioxide alleviates the deterioration of fruit quality in “Daebo” hardy kiwifruit during cold storage.

Changes in Marketability of Strawberry ‘Maehyang’ for Export as Affected by Concentration of Gaseous Chlorine Dioxide Treatment

Changes in Marketability of Strawberry ‘Maehyang’ for Export as Affected by Concentration of Gaseous Chlorine Dioxide Treatment

Slow-release chlorine dioxide gas treatment as a means to reduce Salmonella contamination on spices

Abstract Salmonella enterica is a major food safety issue for the spice industry. Slow-releasing chlorine dioxide (ClO2) gas from self-contained sachets, which can be employed in a small-scale operation, was evaluated for its effectiveness in reducing Salmonella contamination on black pepper, cumin, and sesame seed. Three levels of chlorine dioxide gas (100, 200, or 500 mg ClO2/kg spice) were applied to Salmonella-inoculated spices. Spices were sampled immediately after treatment, and at 1, 10, and 30-days post-treatment. The combined effect of ClO2 gas treatment and storage time on Salmonella numbers on spices was evaluated. Salmonella reductions on black pepper, cumin, and sesame seed samples ranged from 0.81 to 2.74 log CFU/g after ClO2 treatment. Storage time also had a significant impact on Salmonella numbers, as numbers decreased by up to 2.50 log CFU/g over 30 days of storage. Self-contained ClO2 releasing sachets could provide small food processors a post-lethality treatment alternative for spices.

Effect of gaseous chlorine dioxide treatment on the quality of rice and wheat grain

Gaseous chlorine dioxide (ClO2), which is a strong disinfecting agent with strong oxidation properties and penetration ability, is used to control insect pests and fungal contamination in stored grains. However, the effect of gaseous ClO2 on stored grain has yet to be reported. In the present study, we exposed rice and wheat seeds to several concentrations of ClO2 gas for various durations and found that the viability of rice was affected less than that of wheat. After 100 ppm of gaseous ClO2 for 12 h, the normal rice seedling rate was not significantly different than that of the control. However, that of wheat was significantly decreased. We also measured the ClO2 residueon stored rice and wheat after 200 ppm of gas treatment for 24 h. After 10 days of storage following the treatment, ClO2 and chlorine were not detected on either rice or wheat. Chlorite was detected on rice at 0.22 mg/kg of grain; however, it was not detected on wheat. These results suggest that gaseous ClO2 treatment affects the viability of rice and wheat seed but leaves minimal chemical residue.

저농도 서방형 이산화염소 가스 병합처리가 파프리카의 저장 중 미생물 성장과 품질에 미치는 영향

이전 연구에서 이산화염소 가스 훈증처리가 수확 후 파프리카의 미생물학적 안전성을 향상할 수 있다고 보고한 바 있다. 이에 관한 후속 연구로써 본 연구에서는 파프리카의 장기 저장성 확보를 목적으로 저장 중 품질 유지와 부패 감소를 위해 고농도 이산화염소 가스 처리된 파프리카를 8±1 °C, 상대습도 90%의 조건에서 저장하면서 저농도 서방형 이산화염소 가스 발생제(팜이톡, 3 ppmv)를 이용한 추가적인 병합처리를 수행하였다. 저장 초기 이산화염소 가스 병합처리구의 총 호기성 세균은 대조구와 비교하여 3.04 log CFU/g의 감소를 했고, 효모와 곰팡이는 2.70 log CFU/g의 감소를 나타내었으며, 이러한 이산화염소 가스 병합처리의 미생물 저감 효과는 저농도 서방형 이산화염소 가스 발생제 처리로 저장 기간 유지되었다. 특히, 부패율에서 병합처리구가 대조구보다 유의적으로 낮았다. 파프리카의 품질 변화지표(비타민 C 함량, 경도, 색도)와 관련하여 이산화염소 가스 병합처리구와 대조구 모두 저장 기간 차이를 나타내지 않았으나, 저장 중 중량감소율은 병합처리구가 대조구보다 낮은 수준을 유지하였다. 따라서 본 연구 결과, 수확 후 파프리카에 두 가지 형태의 이산화염소 가스를 병합처리 하는 것이 단일처리보다 저장과 유통과정 중 파프리카의 품질을 유지하면서 부패율을 낮출 수 있는 더 효과적인 처리 방법이라고 판단된다.

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

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.

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.

Effect of Chlorine Dioxide Gas Treatment on Surface Sterilization of Grape

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.

Evaluation of Chlorine Dioxide Gas Residues on Selected Food Produce

In recent years, the consumption of fresh fruits and vegetables has greatly increased, and so has its association with contamination of several foodborne pathogens (Listeria, Salmonella, and Escherichia coli). Hence, there is a need to investigate effective sanitizer systems for produce decontamination. Chlorine dioxide (ClO(2)), a strong oxidizing gas with broad spectrum and sanitizing properties, has previously been studied for use on selected fruits and vegetables. ClO(2) gas treatments show great potential for surface pathogen reduction; however its use from a residue safety standpoint has yet to be assessed. Thus, the objective of this study was to evaluate residues of ClO(2), chlorite, chlorate, and chloride on selected fresh produce surfaces after treatment with ClO(2) gas. A rinse procedure was used and water samples were analyzed by N, N-diethyl-p-phenylenediamine and ion chromatography method (300.0). Seven different foods--tomatoes, oranges, apples, strawberries, lettuce, alfalfa sprouts, and cantaloupe--were analyzed after ClO(2) treatment for surface residues. Very low residues were detectable for all the food products except lettuce and alfalfa sprouts, where the measured concentrations were significantly higher. Chlorine dioxide technology leaves minimal to no detectable chemical residues in several food products, thus result in no significant risks to consumers. Practical Application: Potential for chlorine dioxide gas treatments as an effective pathogen inactivation technology to produce with minimal risk for consumers.

Use of high-concentration-short-time chlorine dioxide gas treatments for the inactivation of Salmonella enterica spp. inoculated onto Roma tomatoes

Salmonella outbreaks have been recently linked to the consumption of fresh tomatoes. Thus, there is a need to develop systems that reduce the risk of microbial contamination to increase product shelf-life and keep fresh fruit attributes. The objectives of this study were to evaluate high-concentration-short-time chlorine dioxide gas treatments effects on Salmonella-inoculated Roma tomatoes and determine the optimal treatment conditions for microbial inactivation and shelf-life extension. Effects of ClO 2 concentration (2, 5, 8 and 10 mg/l) and exposure time (10, 30, 60, 120 and 180 s) on inoculated Roma tomatoes were studied. Salmonella enterica strains, serotype Montevideo, Javiana and Baildon, were used to experimentally inoculate the food product. After ClO 2 treatments, tomatoes were stored at room temperature for 28 days. Inherent microbial population, change in tomato color, and chlorine dioxide gas residuals were evaluated. ANOVA analysis showed that both ClO 2 concentration and treatment time were significant ( p < 0.01) for Salmonella inactivation. Surviving Salmonella populations of 3.09, 2.17 and 1.16 log CFU/cm 2 were obtained treating tomatoes with 8 mg/l ClO 2 for 60 s, 10 mg/l ClO 2 for 120 s, and 10 mg/l for 180 s, respectively (initial Salmonella population: 6.03 ± 0.11 log CFU/cm 2). The selected treatments significantly reduced background microflora ( p < 0.05), while fruit color and residual contents were not significantly different ( p > 0.05), as compared to the control. Results suggest the potential for high-concentration-short-time treatments ClO 2 gas as an effective pathogen inactivation technology for large-scale produce packing operations.