ArticleLiterature Review

Electrolyzed Water and Its Application in the Food Industry

Authors:
  • Federal Food Safety and Veterinary Office FSVO
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Abstract

Electrolyzed water (EW) is gaining popularity as a sanitizer in the food industries of many countries. By electrolysis, a dilute sodium chloride solution dissociates into acidic electrolyzed water (AEW), which has a pH of 2 to 3, an oxidation-reduction potential of >1,100 mV, and an active chlorine content of 10 to 90 ppm, and basic electrolyzed water (BEW), which has a pH of 10 to 13 and an oxidation-reduction potential of -800 to -900 mV. Vegetative cells of various bacteria in suspension were generally reduced by > 6.0 log CFU/ml when AEW was used. However, AEW is a less effective bactericide on utensils, surfaces, and food products because of factors such as surface type and the presence of organic matter. Reductions of bacteria on surfaces and utensils or vegetables and fruits mainly ranged from about 2.0 to 6.0 or 1.0 to 3.5 orders of magnitude, respectively. Higher reductions were obtained for tomatoes. For chicken carcasses, pork, and fish, reductions ranged from about 0.8 to 3.0, 1.0 to 1.8, and 0.4 to 2.8 orders of magnitude, respectively. Considerable reductions were achieved with AEW on eggs. On some food commodities, treatment with BEW followed by AEW produced higher reductions than did treatment with AEW only. EW technology deserves consideration when discussing industrial sanitization of equipment and decontamination of food products. Nevertheless, decontamination treatments for food products always should be considered part of an integral food safety system. Such treatments cannot replace strict adherence to good manufacturing and hygiene practices.

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... Compared to chlorine (clorox), EW has competitive advantages including being environmentally-friendly because it only uses water and salt as resources. It doesn't involve production, handling and transportation of using conventional chlorine (Hricova, Stephan, & Zweifel, 2008), economical because the EW production only involves water, salt and electricity. It can be generated on site when needed, being much less costly than conventional chlorine aspect of sanitiser generation, transporting and handling (Hricova et al., 2008;Huang, Hung, Hsu, Huang, & Hwang, 2008), safety thus it has been approved as a food additive in Japan, and the application on food was also approved by both U.S. Food and Drug Administration (FDA) and U.S. Department of Agriculture (USDA) (Hricova et al., 2008), and having strong sanitising effect because of major component being hypochlorous acid and there are some other effective components including free radicals, active oxygen, hydrogen peroxide and ozone gas, which are not existed in clorox and with higher oxidation-reduction potential (ORP) (Yang, Feirtag, & Diez-Gonzalez, 2013). ...
... It doesn't involve production, handling and transportation of using conventional chlorine (Hricova, Stephan, & Zweifel, 2008), economical because the EW production only involves water, salt and electricity. It can be generated on site when needed, being much less costly than conventional chlorine aspect of sanitiser generation, transporting and handling (Hricova et al., 2008;Huang, Hung, Hsu, Huang, & Hwang, 2008), safety thus it has been approved as a food additive in Japan, and the application on food was also approved by both U.S. Food and Drug Administration (FDA) and U.S. Department of Agriculture (USDA) (Hricova et al., 2008), and having strong sanitising effect because of major component being hypochlorous acid and there are some other effective components including free radicals, active oxygen, hydrogen peroxide and ozone gas, which are not existed in clorox and with higher oxidation-reduction potential (ORP) (Yang, Feirtag, & Diez-Gonzalez, 2013). However, at low pH, EW is corrosive, has a short shelf-life, and may be toxic to the operator (Ayebah & Hung, 2005;Waters, Tatum, & Hung, 2014;Xuan et al., 2016). ...
... It doesn't involve production, handling and transportation of using conventional chlorine (Hricova, Stephan, & Zweifel, 2008), economical because the EW production only involves water, salt and electricity. It can be generated on site when needed, being much less costly than conventional chlorine aspect of sanitiser generation, transporting and handling (Hricova et al., 2008;Huang, Hung, Hsu, Huang, & Hwang, 2008), safety thus it has been approved as a food additive in Japan, and the application on food was also approved by both U.S. Food and Drug Administration (FDA) and U.S. Department of Agriculture (USDA) (Hricova et al., 2008), and having strong sanitising effect because of major component being hypochlorous acid and there are some other effective components including free radicals, active oxygen, hydrogen peroxide and ozone gas, which are not existed in clorox and with higher oxidation-reduction potential (ORP) (Yang, Feirtag, & Diez-Gonzalez, 2013). However, at low pH, EW is corrosive, has a short shelf-life, and may be toxic to the operator (Ayebah & Hung, 2005;Waters, Tatum, & Hung, 2014;Xuan et al., 2016). ...
Article
The aim of this study was to develop and evaluate the characteristics and performance of a portable electrolytic sanitising unit. Free available chlorine (FAC), oxidation-reduction potential, and pH of elec-trolysed water were measured. Response surface methodology coupled with a Box-Behnken design was used to describe the input-output relationship and optimise FAC production. A partial catholyte solution was reintroduced to electrolysis for generating neutral electrolysed water. The result found that RuO 2-IrO 2 /TiO 2 electrode was very effective. A FAC concentration of 4 mg/L achieved >2 log CFU/mL reduction, while a FAC concentration of 40 mg/L achieved >6 log CFU/mL reduction in Escherichia coli O157:H7 and Listeria monocytogenes BAA-839. The developed sanitiser had a pH of 7.08 ± 0.08, and the commercial sanitiser had a pH of 3.77 ± 0.18. The developed sanitiser had similar bactericidal effects as the commercial sanitiser. The results revealed that the developed sanitising unit is promising for the control of foodborne pathogens.
... [4][5][6] EW is prepared by electrolysis of tap water by ionizer machines. Depending on the electrolysis process conditions, five types of EW are produced, namely basic (pH: [10][11][12], mildly basic (pH: 8-10), neutral (pH: 6.5-7.5), slightly acidic (pH: 5-6.5), and acidic (pH: [3][4][5]. ...
... Whereas basic electrolyzed water (BEW) is produced in the cathode chamber and, because of its health benefits often applied to suppress oxidative stress-related diseases as well as for its anti-cancer and anti-diabetes properties. [7][8][9][10][11][12] It has been reported that these water types have the ability to destroy all types of anaerobic and aerobic bacteria that cause dental decay. Some mechanisms have been postulated for this antibacterial activity such as the effect of a high or low pH, oxidation-reduction potential, chlorine concentration, and EW's high concentrations of molecular hydrogen. ...
... 27 Some other studies have shown the basic advantages of EW beyond bactericidal activities and demonstrated its application in medicine, 13,28 translational medicine, 29 and the food industry. 12 However, there are reports of unknown systemic effects and growth retardation in rats due to the basic drinking water. 30 In addition, recent reports have claimed that the Hydrogen molecule, rather than pH, is the main cause of beneficial and therapeutic effects of EW. 13,31 Interestingly, and consistent with previous studies, we showed that EW at all pH values amplified cytotoxic activity on the L929 cell line. ...
Article
Background: Microbial plaque-induced oral diseases are among the most common diseases worldwide. The present study aimed to compare the antimicrobial effect of electrolyzed water (EW), (acidic, mildly basic, and basic) on the growth of bacterial species producing dental plaque and to assess their cytotoxicity on fibroblasts and epithelial cells. Methods: The study was performed at Shahid Beheshti University of Medical Sciences in 2019. Several bacterial species (Streptococcus salivarius, Staphylococcus aureus, Lactobacillus casei, and Aggregatibacter actinomycetemcomitans) were treated with different EW types at three pH values (3, 9, and 11) for 30 seconds and subsequently, the colonies were counted. The cytotoxic effect of these EW types was evaluated on HeLa and L929 cell lines at 30 seconds, 1 minute, and 5 minutes. GraphPad Prism 6.0 was used for statistical analysis. The Kruskal-Wallis test followed by Mann-Whitney U and one-way analysis of variance followed by Tukey's test were used to analyze bacterial activity and cell cytotoxicity, respectively. P<0.05 was considered statistically significant. Results: EW types significantly inhibited bacterial growth at all pH values. The strongest antibacterial activity of EW was against A. actinomycetemcomitans (P<0.001) and the least significant antibacterial activity was against S. aureus (P<0.001). The EW types showed increased cytotoxic activity against L929 cells as the treatment time increased. The most cytotoxic effect was seen at 5 minutes of treatment in all EW types compared with the negative control group (P<0.0001). This negative cytotoxic effect on HeLa cells was shown just after 30 seconds and viable cell counts increased over time, reaching its highest value at 5 minutes of treatment with basic EW (P<0.0001). Conclusion: The contradictory effects of the EW types on both HeLa and fibroblasts, in addition to variable results at different exposure times, indicated that the effect of EW could vary depending on cell types and treatment periods.
... Electrolyzed water was originally developed in Japan and Russia to decontaminate and regenerate process water and disinfect medical instruments ( Hricova et al., 2008;Huang et al., 2008). The application of electrolyzed water as an eco-innovative sanitizer has gained interest in the fresh-cut industry considering its potential advantages, including strong bactericidal effect, negligible residual contamination, minimal corrosion of processing equipment or skin irritation and low operational cost ( Hao et al., 2015;Hricova et al., 2008;Mukhopadhyay and Ramaswamy, 2012). ...
... Electrolyzed water was originally developed in Japan and Russia to decontaminate and regenerate process water and disinfect medical instruments ( Hricova et al., 2008;Huang et al., 2008). The application of electrolyzed water as an eco-innovative sanitizer has gained interest in the fresh-cut industry considering its potential advantages, including strong bactericidal effect, negligible residual contamination, minimal corrosion of processing equipment or skin irritation and low operational cost ( Hao et al., 2015;Hricova et al., 2008;Mukhopadhyay and Ramaswamy, 2012). Electrolyzed water is generated by electrolyzing a dilute sodium chloride (NaCl) solution with a current across an anode and cathode that are separated by a bipolar membrane. ...
... Whereas, alkaline electrolyzed water with a pH range of 10-11.5 and an ORP value of ¡800 mV is formed at the cathode ( Huang et al., 2008). In the absence of a bipolar membrane, the mixture of acidic and alkaline solutions produces neutral electrolyzed water, which is characterized by a pH range of 5-8.5, ORP value of 500-700 mV and FCC of 10-30 mg L ¡1 ( Graça et al., 2011;Hao et al., 2015;Hricova et al., 2008). Several studies have suggested that the high ORP of electrolyzed water causes a modification of metabolic fluxes and production of ATP in the bacterial cells due to the change in electron flow ( Pangloli and Hung, 2011;Graça et al., 2011;Hricova et al., 2008). ...
Article
Minimally processed fresh produce is one of the fastest growing segments of the food industry due to consumer demand for fresh, healthy, and convenient foods. However, mechanical operations of cutting and peeling induce the liberation of cellular contents at the site of wounding that can promote the growth of pathogenic and spoilage microorganisms. In addition, rates of tissue senescence can be enhanced resulting in reduced storage life of fresh-cut fruits and vegetables. Chlorine has been widely adopted in the disinfection and washing procedures of fresh-cut produce due to its low cost and efficacy against a broad spectrum of microorganisms. Continuous replenishment of chlorine in high organic wash water can promote the formation of carcinogenic compounds such as trihalomethanes, which threaten human and environmental health. Alternative green and innovative chemical and physical postharvest treatments such as ozone, electrolyzed water, hydrogen peroxide, ultraviolet radiation, high pressure processing, and ultrasound can achieve similar reduction of microorganisms as chlorine without the production of harmful compounds or compromising the quality of fresh-cut produce.
... Acidic electrolyzed water (AEW, pH < 2.7), slightly acidic electrolyzed water (SAEW pH 5.0-6.5) and neutral electrolyzed water (NEW, 6.5-8.5) are the three main types of EWs reported as alternative disinfectants for decontamination. AEW has been reported to be an effective antimicrobial agent in the food industry [20][21][22] . However, AEW can easily release Cl 2 gas due to its volatility, which causes chlorine loss, thus decreasing AEW bactericidal activity over time [23,24] . ...
... The pH of EW is important in the formation of various chlorine species. The relative levels or proportions of available chlorine compounds (Cl 2 , HOCl and OCl -) in EW are pH dependent [21,23,38] . Bactericidal activity of HOCl is much higher than that of OCl - [21,38] . ...
... The relative levels or proportions of available chlorine compounds (Cl 2 , HOCl and OCl -) in EW are pH dependent [21,23,38] . Bactericidal activity of HOCl is much higher than that of OCl - [21,38] . The highest proportion of HOCl of EW was found to be generated at around pH 4-5. ...
Article
Electrolyzed water (EW) can be produced by electrolysis of a dilute salt solution. Slightly acidic electrolyzed water (SAEW, pH 5.0-6.5) and neutral electrolyzed water (NEW, pH 6.5-8.5) are considered healthy and environmentally friendly because no hazardous chemicals are added in its production, there is reduced corrosion of surfaces and it minimizes the potential for damage to animal and human health. Over the last decade, EW has become increasingly popular as an alternative disinfectant for decontamination in animal houses. However, there have been some issues related to EW that are not well known, including different mechanisms for generation of SAEW and NEW, and the antimicrobial mechanism of EW. This review covers the definitions of SAEW and NEW, different generation systems for SAEW and NEW, the antimicrobial mechanism of EW, and recent developments related to the application of SAEW and NEW in animal houses.
... For some of these reasons the use of EW in food industry has increased significantly (Hricova et al., 2008;Huang et al., 2008). Several studies have reported that EW is effective in reducing the growth of different microorganisms during the postharvest storage of many fruit and vegetables (Al-Haq, Seo, Oshita, & Kawagoe, 2002;Guentzel et al., 2010;Guentzel, Callan, Lam, Emmons, & Dunham, 2011;Okull & Laborde, 2004;Whangchai, Saengnil, Singkamanee, & Uthaibutra, 2010). ...
... Therefore, depending on the molecule structure, the rate and yield of these processes may vary considerably. EW at pH 9 contains primarily hypochlorite ions (ClO − ; 80-95%), which leave chlorine residue on fruit surfaces (Hricova et al., 2008). In our study, the detection of chloroanisoles in wines may suggest that the residual chlorine on grapes after EW treatment and storage under controlled temperature in the dark could have promoted the microbiological formation pathway of TCA and therefore its presence in wine. ...
Article
Electrolyzed water (EW) has attracted much recent attention as a high-performance, new technology for its potential use in the food industry. However, the risk of postharvest EW treatments of winegrapes destined for winemaking is the chloroanisoles formation in the final product. In the present study, we investigated the impact of postharvest grape EW and storage treatments on the occurrence of these compounds in wine, 2,4,6-trichloroanisole (TCA) being the main compound responsible for the cork taint off-flavor due to its extremely low perception threshold. The results revealed that the presence of TCA in the wines depended on the concentration of residual free chlorine in the must from the EW treatment. Particularly, TCA was not detected in wine when active chlorine concentrations higher than 0.005 mg/L were present in the must. Chloroanisole and chlorophenol levels in wine were strongly affected not only by EW but also by grape storage conditions (temperature, time, sunlight exposition). The results showed that the 24-hours grape storage at a controlled temperature of 20 °C in the dark, after EW treatment, resulted in the highest TCA concentrations in wines (7.3 ± 2.7 ng/L), while storage and withering in sunlight seemed to mitigate its presence in wine. This could suggest that microbiological formation of chloroanisoles may have been influenced by the storage temperature and germicidal effect of UV light. Biochemical mechanism of chloroanisoles production in grapes and wine is unknown, but the combination of residual free chlorine on the grape surface and the controlled storage conditions in the dark may have positively influenced the bio-formation of chloroanisoles and therefore their presence in wine.
... Initially, its application on human tissues was avoided due to its physicalchemical characteristics such as very acid or alkaline pH, instability, and toxicity. However, its use was implemented in agriculture, the food industry, and in the disinfection of various surfaces and inert materials by its high microbicidal capacity [22]. us, electrolyzed solutions of superoxidation (ESS) with a near-neutral pH (6.4-7.5) ...
... According to many studies, the presence of chlorine and a high concentration of ORP in ESS seem to be the responsible of its antimicrobial activity. Active chlorine compounds can destroy the membranes of microorganisms, but other modes of chlorine action (e.g., decarboxylation of amino acids, reactions with nucleic acids, and unbalanced metabolism a er the destruction of key enzymes) also have been proposed [22]. Studies suggest that HOCl is the most active of the chlorine compounds. ...
Article
Full-text available
The presence of Helicobacter pylori in the oral cavity has been associated to the failure of antimicrobial therapy in patients with gastrointestinal infection and the development of oral diseases. However, it has been reported that the maintenance of good oral hygiene can improve the therapeutic success rates, where the use of mouthwashes with anti-Helicobacter activity would help to achieve it. The aim was to evaluate the antimicrobial activity of OxOral® mouthwash against H. pylori and its effect on biofilm formation. The minimum inhibitory concentration (MIC) of OxOral® (pH = 6.4-7.5, ORP = 650-900 mV) against H. pylori was calculated testing serial dilutions 0.117-15 ppm against 1 × 10 8 CFU/mL of H. pylori (ATCC® 700824™) by broth microdilution method using 96-well plates. The H. pylori biofilm formation was determined by the optical density measurement at 600 nm from coverslips stained with 0.1% crystal violet. The gene expression of ureA, luxS, flaA, omp18, and lpxD were analyzed by RT-qPCR. OxOral® cytotoxicity was evaluated in a human gingival fibroblast cell line by MTT assay. MIC was of 3.75 ppm, with 99.7 ± 7.7% bacterial growth inhibition. In the negative control, the biofilm formation was observed, whereas when bacteria were treated with OxOral® at 0.234, 0.469, and 0.938 ppm, an inhibition of 35.5 ± 0.9%, 89.1 ± 1.2%, and 99.9 ± 5.5% were obtained, respectively. The gene expression analysis showed that flaA, omp18, and lpxD genes were down-regulated with OxOral® compared with control (í µí± < 0.05). Low cytotoxicity of 16.5 ± 7.6% was observed at the highest dose (15 ppm); no significant differences were observed from 15 to 0.469 ppm compared to the control of untreated cells (í µí± > 0.05). Our results reveal an important anti-Helicobacter activity of OxOral® and open the possibility of its therapeutic use new studies, which would increase the success rate of conventional therapies against H. pylori.
... Liquid chlorine, hypochlorite, inorganic and organic chloramines, chlorine dioxide, and hypochlorous acid are common chlorine-based sanitizers. In practice, chlorine-based sanitizers are produced as highly concentrated and corrosive chemical solutions, which are diluted before use, and therefore introduce workers' health and safety issues during storage and application [5,6]. ...
... At the anode, acidic electrolyzed water with a pH of 2-3 and oxidation-reduction potential (ORP) >1100 mV is produced, whereas at the cathode, basic electrolyzed water with a pH of 10-13 and ORP of 800 to 900 mV is produced. Neutral electrolyzed water with a pH of 7-8 and ORP of 750-900 mV is produced by mixing the anodic solution with OH − ions or by using a single-cell unit without diaphragm [6,10,11]. ...
Article
Full-text available
The present study comprised five trials to investigate the efficacy of postharvest treatment with electrolyzed oxidizing (EO) water on postharvest disease development in avocado. Mature (dry matter 24–34%), hard green fruit cv. Hass (four trials), and cv. Wurtz (one trial) from orchards receiving minimal fungicide sprays were sourced, and subsequently dipped for 30 s in treatment solutions. Fruit were ripened at 23 °C and 65% relative humidity to encourage postharvest disease development, and assessed when ripe for anthracnose and stem end rot (SER), arising from natural field infections and/or the size of lesions resulting from post-treatment inoculation with Colletotrichum siamense. In the case of natural infection, EO water treatment reduced severity of SER disease by 30–75% compared with water treated control fruit in all four trials where it was assessed. Reduction in severity of SER after Graduate A+ fungicide or hypochlorite (NaOCl) bleach treatment ranged from 60–88% or 25–50%, respectively, compared with water controls. Under extremely high anthracnose disease pressure, 20% v/v EO water, NaOCl, as well as Graduate A+ fungicide treatments were mostly ineffective. Treatments in the final trial were applied as overhead sprays in an experimental-scale packing line to simulate commercial conditions. This was the only trial where anthracnose (as well as SER) was significantly reduced in fruit by 20% v/v EO water (12–35%) and Graduate A+ (34%) compared with water control. In two trials with C. siamense-inoculated fruit, anthracnose lesion size was reduced by 68–85%, and 90–100% by 20% v/v EO water and Graduate A+, respectively, compared with water-treated fruit. Fruit firmness and the number of days to ripen were mostly not affected by the treatments. This study demonstrates the potential for electrolyzed oxidizing water to be incorporated into integrated management programs for postharvest diseases of avocado, and possibly other fresh produce.
... The production involves an electrolysis chamber with an anode and a cathode physically separated by a membrane ( Cheng et al., 2012;Demirci & Bialka, 2010;Deza, Araujo, & Garrido, 2003). When electrodialysis occurs two separate streams are formed: one acidic (at the anode) and the other alkaline (cathode) ( Hricova, Stephan, & Zweifel, 2008;Ongeng, Devlieghere, Debevere, Coosemans, & Ryckeboer, 2006). NEOW is the combination of these two solutions ( Cheng et al., 2012). ...
Article
Microbial contamination is an unavoidable problem in industrial processes. Sodium hypochlorite (SH) is the most common biocide used for industrial disinfection. However, in view of the current societal concerns on environmental and public health aspects, there is a trend to reduce the use of this biocide as it can lead to the formation of organochlorinated carcinogenic compounds. In this work the efficacy of SH was assessed against Escherichia coli in planktonic and biofilm states and compared with three alternative chlorine-based biocides: neutral electrolyzed oxidizing water (NEOW), chlorine dioxide (CD) and sodium dichloroisocyanurate (NaDCC). The planktonic tests revealed that SH had the fastest antimicrobial action, NaDCC exhibited the highest antimicrobial rate and NEOW caused the highest antimicrobial effects. Additionally, NEOW was the biocide that allowed the highest formation of reactive oxygen species (ROS). In biofilm control, NEOW and CD were the most efficient biocides causing 3.26 and 3.20 log CFU·cm− 2 reduction, respectively. In terms of stability for chlorine depletion, NEOW had the longest decay time for chlorine loss (70 days at 5 °C) and the lowest chlorine loss rate (0.013 ppm·min− 1 at 5 °C). CD and NaDCC had equivalent stability. The overall results demonstrated NEOW as a good alternative to SH due to its higher antimicrobial effects and lower chlorine depletion over time.
... A lot of research has been carried out on poultry carcass decontamination techniques, especially because poultry is involved as a risk factor in human campylobacteriosis (Loretz et al., 2010). Physical interventions include water-based treatments, irradiation, ultrasound, air chilling or freezing (Sams and Feria, 1991;Farkas, 1998;Avens et al., 2002;Fabrizioe et al., 2002;Purnell et al., 2004;Escudero-Gilete et al., 2005;Huezo et al., 2005;Hricova et al., 2008;Kondojoyan and Portaguen, 2008;Boysen and Rosenguist, 2009). Especially hot water, steam, electrolyzed water and irradiation effectively reduce bacterial load. ...
Article
European Union legislation approach to meat safety assurance advocates use of strict preventive hygiene measures and procedures to overcome threats by pathogens. Therefore, there is no need for carcass decontamination at the last stage of slaughtering process, using intervention methods. In contrast, the United States permit and regulate intervention decontamination methods. Generally, a HACCP system may use intervention treatments. These may be based solely on a non intervention system or use a combination of both. Interventions have the advantage of achieving a consistent reduction in bacterial contamination and require less manual input, but on the other hand, may also lead to carcass discolouration, produce large quantities of waste water and be relatively expensive. Moreover, intervention methods could constitute a means of concealing poor hygiene conditions during slaughtering or, even more, their residues could be a potential hazard for food safety. Non-intervention systems have the advantages of being relatively inexpensive, easy to implement and more preventive. However, these systems rely heavily on human effort and the possibility for error is considerably higher than the intervention systems. There are many carcass decontamination methods, as described in the relevant literature and used in slaughterhouses worldwide, such as: (i) cold/warm water washing, (ii) hot water washing, (iii) steam vacuuming, (iv) steam pasteurization, (v) irradiation, (vi) organic acid application, (vii) combination of organic acid application with other decontamination treatments and (viii) other chemical treatments. Aim of this review is to provide information on the relevant literature, as well as describe and Ncomment on the questions raised.
... In the last years, new disinfecting agents are being proposed for fruits and vegetables treatment, such as ozone (O 3 ) and electrolyzed water (EW) (Boonkorn et al., 2012;Guentzel, Lam, Callan, Emmons, & Dunham, 2010;Hricova, Stephan, & Zweifel, 2008;Smilanick, Margosan, & Mlikota Gabler, 2002.). EW has a broad spectrum of action against various microorganisms thanks to three combined actions: hydrogen ions, oxidation-reduction potential and free chlorine, while, ozone is a strong oxidant able to attack several cellular constituents of the microorganisms, in addition to this, eco-friendliness and easiness of on site application are other main advantages of these agents (Jermann, Koutchma, Margas, Leadley, & Ros-Polski, 2015;Khadre, Yousef, & Kim, 2001). ...
Article
In this study, we investigated the possible effect of electrolyzed water (EW), aqueous ozone (WO) and gaseous ozone (GO) on Brettanomyces bruxellensis DSM 7001 strain artificially inoculated on the grape surface and on its evolution during the subsequent, inoculated must fermentation. Culture-dependent and -independent techniques were used to evaluate the effectiveness of treatments against B. bruxellensis, as well as its presence during fermentation. Particularly, GO treatment of 24 h decreased its presence by about 2.1 Log, making it possible to reduce significantly the concentration of ethylphenols in the wine in relation to the control wine. EW and WO treatments caused less relevant reductions. The results showed that all the treatments reduced the presence of this yeast on grapes. However, in these experimental conditions it was not possible to achieve a complete removal of this undesirable yeast.
... Fruits, vegetables, and other food products should retain their nutritional value and safety until they are consumed. The use of chlorine compounds, organic acids, trisodium phosphate, iodine solutions, and ammonia compounds are common in overcoming food spoilage (Hricova et al., 2008). On the other hand, these conventional techniques have many drawbacks. ...
... Previously, researchers have tried to control E. cloacae contamination with photocatalytic disinfection, which only decreased the cell numbers by 3 to 4 log CFU/mL, and was not ideal (Ede, Hafner, Dunlop, Byrne, & Will, 2012;Ibáñez, Litter, & Pizarro, 2003). Currently, EOW has gained immense popularity as a novel disinfectant, and the antimicrobial mechanisms of EOW have been reported to be composed of several factors, including the presence of chlorine, high ORP values, increase of membrane permeability, and the oxidation of key metabolic systems (Hricova, Stephan, & Zweifel, 2008;Rahman et al., 2016). Sun et al. (2012) confirmed that EOW is very effective in eliminating bacterial biofilms from stainless steel surfaces. ...
Article
Full-text available
Bacterial biofilms formed on equipment surfaces are potential sources of cross‐contamination and can be responsible for the spread of bacteria involved in food spoilage, such as some Enterobacteriaceae family members. In this study, the effect of chlorite‐based disinfectants, including sodium hypochlorite (SH), chlorine dioxide (CD), strongly acidic electrolyzed water (StAEW), and neutral electrolyzed water (NEW), on inactivation of mono‐biofilms of Enterobacter cloacae, Klebsiella oxytoca, and Citrobacter freundii was evaluated separately. All the strains were enumerated by the viable plate‐count method after disinfection for 30 min. A comparison of the surviving cells after disinfection indicated that E. cloacae biofilms were more resistant to disinfectants than the biofilms of the other two strains, and treatment with all the disinfectants improved sanitizing. SH (200 mg/L) was the most effective in the reduction of cell number in the biofilms of all strains. Considering the safety of use and environmental protection, electrolyzed oxidizing water, especially StAEW, was a good suggestion for the inactivation of cells in K. oxytoca or C. freundii biofilms. These results suggest that the cells in biofilm of E. cloacae, K. oxytoca, and C. freundii were highly sensitive to chlorite‐based disinfectants and provide insights into the efficacy of disinfectants in killing bacteria. Practical Application The Enterobacteriaceae biofilms formed on equipment surfaces, which can cause cross‐contamination and food spoilage, are greatly challenging bacterial contaminants of food products. Electrolyzed oxidizing water is a novel, environmentally friendly disinfectant that can effectively treat Enterobacteriaceae biofilms. The results of this study may be used to design effective measures to disinfect biofilms on equipment contact surfaces.
... It is uncharged in the undissociated HClO form and can therefore better penetrate biological matter compared to hypochlorite but is rapidly consumed by reaction on contact with proteinaceous organic matter. This property is advantageous because after it reacts, no potentially harmful chlorine remains, although it also means EW is quick to lose its reactiveness (Hricova et al., 2008). HClO kills microbial cells by a number of means including inhibiting glucose oxidation (Huang et al., 2008;Koseki et al., 2001). ...
Article
The extent and type of microbial growth on barley grain is a key determinant of malt quality for beer production, as problematic microbial products can persist into the brewing process and impact beer quality. Microbial composition on malting barley grain are influenced by field growth, storage and malting conditions. The present study investigated the efficacy of electrolysed water (EW) with free chlorine concentrations of 5, 50, 100 and 500 ppm, as well as peroxyacetic acid (PAA) at 100 and 500 ppm, as pre-steep treatments to control microbes on grains during the malting process. The research determined the reduction in the load of Pseudomonas spp., heterotrophic bacteria, yeasts and filamentous fungi on weathered and on non-weathered grains. Pseudomonas spp., heterotrophic bacteria and yeasts were significantly reduced up to 4 logs when treated with 500 ppm PAA. PAA reduced filamentous fungi but 500 ppm free chlorine EW showed greater reductions. None of the treatments had detrimental effect on grain germination. The variation in antimicrobial efficacy among treatments can be attributed to variations in microbial susceptibility as well as differences in anti-microbial mechanisms specific to each antimicrobial agent.
... Electrolyzed water (EW) was an effective disinfectant, which could be produced by electrolysis of a dilute salt solution. Three types of EW, electrolyzed water (AEW; pH < 2.7), slightly acidic electrolyzed water (SAEW; pH 5.0-6.5), and neutral electrolyzed water (NEW, pH 6.5-8.5), were considered as alternative disinfectants compared with common chemical sanitizer in food and egg industries (Hricova, Stephan, and Zweifel 2008;Huang et al. 2008;Rahman, Khan, and Oh 2016;Zheng et al., 2016b). The combination of antiseptic effect of the disinfectant and washing effect of the scrubber achieved high removal efficiency of microorganisms . ...
Article
Electrolyzed water (EW) is an effective disinfectant with a wide range of pH. EW in acid range was proved to be ammonia absorbent which make it valuable for wet scrubbers used in animal feeding operations (AFOs). This study aimed to optimize the design and operating parameters of a wet scrubber with EW spray for ammonia removal, based on the size distribution of droplets, the property of EW and the reduction efficiency of ammonia. The optimized parameters included droplet size, nozzle flow rates, pH and available chlorine concentration (ACC) of EW, nozzle number at single stage, stage number, initial ammonia concentration and air speed in the duct. The ammonia removal efficiency increased with the decrease of droplet size and the increase of flow rate. The pH values of EW showed significant influence on ammonia removal efficiency (P ? 0.05), while ACC of the EW showed no significant influence (P ? 0.05). For inlet ammonia concentration of 70 ppm with one and three spray stages, the wet scrubber with EW (pH = 1.35) spray was able to reduce 55.8 ± 4.3 % and 97.2 ± 3.0 % of ammonia, respectively, when the nozzles with 0.9 mm orifice diameter operated at a flow rate of 1.20 L min<sup>-1</sup>. Response surface analysis showed that orifice diameter, nozzle flow rate, and their combination were all significant factors impacting ammonia removal efficiency for both pH =1.35 and 5.50 at a 95 % confidence level. Optimal ammonia removal efficiency was obtained at orifice diameter 0.9 mm and flow rate 1.20 L min<sup>-1</sup> within the selected range. The results of this study demonstrated that wet scrubber with EW spray could be a very effective and feasible ammonia mitigation technology for AFOs.
... The low pH value of AEW (range: 2.69-2.91) might promote decreases in pHi due to its ability to alter internal pH gradients, which can render bacterial cells more sensitive to active chlorine by sensitizing their cell membrane to the entry of HOCl (Hricova et al., 2008). ...
Article
Pseudomonas spp. have emerged as the main spoilage bacteria, with many strains easily forming biofilms on food-contact surfaces and causing cross-contamination. The efficacy of disinfectants against bacteria is usually tested with planktonic cells; however, the disinfection tolerance of biofilms, especially detached biofilms, remains unknown. Here, we investigated the tolerance responses of detached and adhered biofilms of Pseudomonas fluorescens to acidic electrolyzed water (AEW) by determining tolerance responses by plate counting, comparing them using a Weibull model, and verifying changes in bacterial morphology by scanning electron microscopy. The experimental data and the responses calculated using Weibull a (scale) and b (shape) parameters agreed well (R ² values: 0.974–0.999), and we found that AEW exhibited effective antimicrobial activity against P. fluorescens, with adhered biofilms were more resistant than detached biofilms and planktonic cells. Additionally, AEW increased the bacterial membrane permeability and decreased the membrane potential, intracellular ATP concentrations, and intracellular pH while also triggering the disruption of extracellular polymeric substances. These results demonstrated that the morphophysiological responses of detached and adhered biofilms differed significantly and provided information on disinfectant-resistance strategies potentially beneficial to the development of novel disinfection approaches.
... 13e15 EW is a product of electrolysis of a dilute sodium chloride solution in an electrolysis cell into acidic electrolyzed water and basic electrolyzed water. 16 EW is gaining popularity as a sanitizer in the food industry with the merits of low irritation of tissues, robust bactericidal and virucidal effects, low cost and non-polluting. 17e19 Reports have mentioned that EW is effective as a sterilizer for medical instruments in hospitals 20 and also useful for the sterilization of dental chairs pipelines, 21 impression material, 22,23 denture bases, 24 mouth rinse 25 and root canal irrigants 14,15 in dental field. ...
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Background/purpose: Electrolyzed water has been identified as an effective disinfectant that could represent as an alternative to sodium hypochlorite. Unfortunately, it remains unclear whether the texture or physical properties of dentin are affected by the application of electrolyzed water of different acidities. This study was aimed to assess the influence of electrolyzed waters with differing pHs on the demineralizing of inner dentin. Materials and methods: The coronal superficial dentin of 20 human molars was exposed and further bisected into two pieces perpendicular to the dentin surface. The samples were immersed in strongly acidic electrolyzed water (AW group), neutral electrolyzed water (NW group), 5% sodium hypochlorite (positive control, NL group), or deionized water (negative control, DW group). Microhardness of the inner layer dentin was measured at a depth of 25 and 50 μm beneath the superficial surface layer every 5 up to 60 min. Results: At a depth of 25 μm, microhardness decreased with increasing immersion time in all but the DW group. The AW group exhibited a decreasing trend from the first 5 min that became significant after 35 min of immersion and was the most rapid decrease in the four groups. The rate of decline in the NW group was low and similar to that of the NL group. Both NW and NL groups exhibited significantly less demineralization than the AW group after 15 min of immersion. No significant microhardness change was found at a depth of 50 μm in any of the samples. Conclusion: AW produces a more pronounced softening of dentin than NW at a depth of 25 μm.
... The application of a galvanic current produces a physical phenomenon known as electrolysis which has a recognized power of disinfection against viruses and bacteria 1 . Through different types of electrodes, electrolysis has been used for disinfection of hands and surfaces 2 , medical and dental supplies 3,4 , surgical procedures 5 , food 6,7 and even industrially, in swimming pools and wastewater 8,9 . Traditionally, physiotherapists have also used the application of a galvanic current for other additional therapeutic purposes by using either electrodes or acupuncture needles. ...
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Percutaneous needle electrolysis using tri-beveled needles with a specific protocol (5 mA applied for 25 s) has demonstrated to provoke a clinical reduction of recurrent bacterial infections in mammary fistulas. However, the bactericidal effect of needle electrolysis in this pathology remains theoretical. This in vitro study evaluated the bactericidal effect of this protocol and whether it changed when introducing small variations. Staphylococcus aureus were generated in saline solution (9 Log10 CFU/mL) and treated in three different experiments including the main protocol and introducing variations in needle gauge, intensity, and total dosage, respectively. After 24 h, the viable cell count showed that the protocol had an average reduction of 5 log10 CFU/ml compared to the control group. While variations in needle gauge did not modify this effect, variations in current intensity or dosage did. This study demonstrated that the bacterial effect was greater by increasing either current intensity or total dosage, and it decreased with substantial reductions of these parameters.
... Typically, electric current oxidizes the chloride ions (Cl − ) in water to produce chlorine (Cl 2 ), which forms hypochlorous acid (HClO) and hypochlorite ions (ClO − ) by reacting with water [70]. Like free chlorine ions, they have a bactericidal effect due to their strong oxidizing properties [72]. The electrolysed water indeed has showed microbicidal effects on the microorganisms in waterlines and exhibits low cytotoxicity to human oral-derived cells [70]. ...
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Background. Severe contamination of dental unit waterlines was found in healthcare settings. The benefits of decontamination methods are controversial. The aim of this review was to systematically evaluate disinfection methods in contamination control of dental unit waterlines. Methods. The terms ‘dental unit waterline(s) or DUWL(s) or dental unit water line(s)’ were searched through PubMed, Cochrane Library, Embase, Web of Science and Scopusup to 31 May 2021. The DUWLs’ output water was incubated on R2A agar at 20–28 °C for 5–7 days to evaluate heterotrophic mesophilic bacteria. The risk of bias was evaluated by a modified Newcastle-Ottawa quality assessment scale. Results. Eighteen papers from the literature were included. One study indicated that water supply played a crucial role in disinfecting DUWLs. Three studies indicated that flushing decreased bacteria counts but did not meet the American CDC standard (500 c.f.u. ml ⁻¹ ). All chlorine- and peroxide-containing disinfectants except sodium hypochlorite in one of 15 studies as well as three mouthrinses and citrus botanical extract achieved the standard (≤500 c.f.u. ml ⁻¹ ). The included studies were of low (1/18), moderate (6/18) and high (11/18) quality. Conclusion. Independent water reservoirs are recommended for disinfecting DUWLs using distilled water. Flushing DUWLs should be combined with disinfections. Nearly all the chlorine-, chlorhexidine- and peroxide-containing disinfectants, mouthrinses and citrus botanical extract meet the standard for disinfecting DUWLs. Alkaline peroxide would lead to tube blockage in the DUWLs. Regularly changing disinfectants can reduce the risk of occurrence of disinfectant-resistant strains of microbes.
... and low oxidation-reduction potential (ORP) (− 800 to − 900 mV) produced from the cathode side. Currently, EW finds its applications in medical (Sakurai et al., 2003), agricultural, and agro-processing industries (Al-haq et al., 2005;Hricova, Stephan, & Zweifel, 2008;Huang et al., 2008). One of the most significant advantages of EW is its on-site production, which reduces its transportation, storage, and handling charges and the hazards associated with these operations (Al-haq et al., 2005). ...
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The application of pesticides enhances food production vastly, and it cannot be prevented; longer fresh produce is contaminated with health-threatening pesticides even though traditional processing methods can remove these pesticides from food surfaces to a certain extent; novel emerging technologies such as cold plasma, ultrasound, electrolyzed water, and pulsed electric field could more effectively dissipate the pesticide content in food without the release of toxic residual on the food surface. The present review focuses on applying emerging technologies to degrade pesticide residues in great utility in the food processing industries. This review also discusses the pesticide removal efficacy and its mechanism involved in these technologies. The oxidation principle in cold plasma is recently gaining more importance for the degradation of pesticide residue in the food processing industries. Analysis of the emerging physical processing methods indicated greater efficacy in eradicating pesticide residues during agriculture processing. Even though the technologies such as EO (99% reduction in dimethoate), ultrasound (98.96% for chlorpyrifos), and irradiation (99.8% for pesticide in aqueous solution) can achieve promising results in pesticide degradation levels, the rate and inactivation of highly depend on the type of equipment and processing parameters involved in different techniques, surface characteristics of produce, treatment conditions, and nature of the pesticide. Therefore, to effectively remove these health-threatening pesticides from food surfaces, it is necessary to know the process parameters and efficacy of the applied technology on various pesticides.
... In this study, we demonstrated that a unique electrolyzed water SAIW was a safe disinfectant effective to enveloped and nonenveloped viruses and Gram-negative bacteria. So far, the antibacterial effect of acidic electrolyzed water has been primarily studied, and many of them focused on the effect of free available chlorine (FAC) in the electrolyzed water [17,18]. Recently, it was reported that a neutral electrolyzed water (pH 7) reduced human norovirus RNA copy by 4.8-log10 after suspension for 1 min in the presence of 250 ppm FAC [19]. ...
Article
Air spaces and material surfaces in a pathogen-contaminated environment can often be a source of infection to humans, and disinfection has become a common intervention focused on reducing the contamination levels. In this study, we examined the efficacy of SAIW, a unique electrolyzed water with chlorine-free, high pH, high concentration of dissolved hydrogen, and low oxygen reduction potential, for the inactivation of several viruses and bacteria. Infectivity assays revealed that initial viral titers of enveloped and non-enveloped viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) influenza A virus, herpes simplex virus type 1, human coronavirus, feline calicivirus, and canine parvovirus, were reduced by 2.9- to 5.5-log10 within 30 s of SAIW exposure. Similarly, the culturability of three Gram-negative bacteria (Escherichia coli, Salmonella, and Legionella) dropped down by 1.9- to 4.9-log10 within 30 s of SAIW treatment. Mechanistically, treatment with SAIW was found to significantly decrease the binding and subsequent entry efficiencies of SARS-CoV-2 on Vero cells. Finally, we showed that this chlorine-free electrolytic ion water had no acute inhalation toxicity in mice, demonstrating that SAIW holds promise for a safer antiviral and antibacterial disinfectant.
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We developed a top-down strategy to characterize an antimicrobial, oxidizing sanitizer, which has diverse proposed applications including surface-sanitization of fresh foods, and with benefits for water resilience. The strategy involved finding quenchers of antimicrobial activity then antimicrobial mode of action, by identifying key chemical reaction partners starting from complex matrices, narrowing down reactivity to specific organic molecules within cells. The sanitizer electrolyzed-water (EW) retained partial fungicidal activity against the food-spoilage fungus Aspergillus niger at high levels of added soils (30–750 mg mL–1), commonly associated with harvested produce. Soil with high organic load (98 mg g–1) gave stronger EW inactivation. Marked inactivation by a complex organics mix (YEPD medium) was linked to its protein-rich components. Addition of pure proteins or amino acids (≤1 mg mL–1) fully suppressed EW activity. Mechanism was interrogated further with the yeast model, corroborating marked suppression of EW action by the amino acid methionine. Pre-culture with methionine increased resistance to EW, sodium hypochlorite, or chlorine-free ozonated water. Overexpression of methionine sulfoxide reductases (which reduce oxidized methionine) protected against EW. Fluoroprobe-based analyses indicated that methionine and cysteine inactivate free chlorine species in EW. Intracellular methionine oxidation can disturb cellular FeS-clusters and we showed that EW treatment impairs FeS-enzyme activity. The study establishes the value of a top-down approach for multi-level characterization of sanitizer efficacy and action. The results reveal proteins and amino acids as key quenchers of EW activity and, among the amino acids, the importance of methionine oxidation and FeS-cluster damage for antimicrobial mode-of-action.
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Studies on slightly acidic electrolyzed water (SAEW) for decontamination and shelf life extension of beef are limited. This study aimed to evaluate the effects of SAEW and tea polyphenols (Tpp) on the microbiological, physicochemical, and sensory qualities of fresh beef during storage. The changes in total viable count, thiobarbituric acid content, pH, total volatile basic nitrogen, and sensory scores revealed that the required quality standard of the beef treated with distilled water, Tpp, and SAEW was maintained for up to 6–8, 12–14, and 14–16 days, respectively. These results demonstrated that SAEW could effectively extend the shelf life of beef in comparison with that of other treatments. However, there were no significant differences (p > 0.05) between the untreated and SAEW‐treated group in the content of thiobarbituric acid, suggesting that SAEW does not possess antioxidant activity. Therefore, further studies are required to increase its antioxidant activity. This study suggests that SAEW treatment is an effective and promising method to prolong the shelf life of beef by around 8 days at 4°C. Our study found that SAEW could effectively extend the shelf life of beef in comparison with that of other treatments. However, there were no significant differences (p > 0.05) between the untreated and SAEW‐treated groups in the content of thiobarbituric acid, suggesting that SAEW does not possess antioxidant activity, and further studies are required to increase its antioxidant activity.
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Foodborne disease outbreak caused by food microbiological contamination is a serious public health problem. Slightly acidic electrolyzed water (SAEW), a new ultra-high effect and wide-spectrum disinfectant that is colourless, odourless, and harmless to humans and the environment, is directly used on food surfaces in Japan and America. However, the underlying inactivation mechanism remains unknown. In this study, biochemical and cellular changes were observed to investigate the bactericidal mechanism of SAEW against Escherichia coli (E. coli). The results indicated that SAEW with a pH of 6.40, an oxidation-reduction potential (ORP) of 910 mV, an available chlorine concentration (ACC) of 60 mg/L, and a volume ratio of 20:1, produced the most effective sterilization action. A fluorescence-based live-dead assay was further used to demonstrate the sterilized effect and the cell esterase activity damage caused by SAEW. During the observation period, within 10 min, the cell morphology changed, which was characterized by cell expansion, cell elongation and increased membrane permeability. Meanwhile, reactive oxygen substances (ROS) were released in the bacterial cells. E. coli inactivation and apoptosis induced by SAEW were observed. Our findings illustrate that the bactericidal effects of SAEW against E. coli occurred through cellular and biochemical mechanisms of cell necrosis and apoptosis.
Article
Fruits and vegetables (F&V) provide people with a variety of essential vitamins, antioxidants and dietary fiber, thus constituting integral components of human diet. With the surge of interest in F&V, their consumption ratio has kept increasing in recent years. Unfortunately, microorganisms and pesticide residues on the surfaces of F&V may be hazardous to humans. As an emerging technology, electrolyzed water (EW) shows great application potential in reducing these hazards. EW treatment not only effectively removes microorganisms from F&V, but also degrades pesticide residues on their surfaces. In addition, EW treatment affects the physiological metabolism of harvested F&V, which is conducive to maintain their sensory quality and nutritional value. This article reviews the principles of EW preparation, advantages and disadvantages, and the application of EW in F&V in the last decade, including disinfection of irrigation water, removal of pesticide residues, disinfection after harvest, and its effects on physicochemical parameters and enzyme activity of F&V etc. Moreover, the combination of EW and other technology, including ozone, short‐time heat treatment, ultraviolet irradiation, and ultrasound, to further improve the quality control effects of F&V is discussed.
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Electrolyzed water (EW) is a new type of cleaning and disinfecting agent obtained by means of electrolysis with a dilute sodium chloride solution. It has low cost and harm to the human body and is also friendly to the environment. The anode produces acidic electrolyzed water (AEW), which is mainly used to inhibit bacterial growth and disinfect. The cathode provides basic electro-lyzed water (BEW), which is implemented to promote human health. EW is a powerful multifunc-tional antibacterial agent with a wide range of applications in the medicine, agriculture, and food industry. Studies in vitro and in vivo show that it has an inhibitory effect on pathogenic bacteria and viruses. Therefore, EW is used to prevent chronic diseases, while it has been found to be effective against various kinds of infectious viruses. Animal experiments and clinical trials clearly showed that it accelerates wound healing, and has positive effects in oral health care, anti-obesity, lowering blood sugar, anti-cancer and anti-infectious viral diseases. This review article summarizes the application of EW in treating bacteria and viruses, the prevention of chronic diseases, and health promotion.
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Adaptive exposure to sub-lethal concentrations of sanitizers was previously reported to offer cross-protection to bacteria against antibiotics. This study was undertaken to determine whether the pre-exposure of fecal coliforms to suboptimal concentrations of a chemical sanitizer, chlorine dioxide (ClO2), alters their susceptibility to certain antibiotics. Fecal coliforms isolated from fresh fruit packing facilities (n = 12) were adapted in ½ or ¼ of the manufacturer-recommended concentration of ClO2. The susceptibility of the adapted and non-adapted cells to 13 different antibiotics was determined by observing the changes in their minimal inhibitory concentrations (MICs). The results showed that preadaptation to the suboptimal concentrations of ClO2, in general, either decreased or did not change the MICs of the antibiotics against selected fecal coliform isolates, with only two exceptions; preadaptation increased the MICs of kanamycin against two of the fecal coliform isolates, and of nalidixic acid against one of the fecal coliform isolates. The results suggest that the use of ClO2 has a relatively low risk of inducing the resistance of fecal coliforms to antibiotics.
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In this paper, anolyte is considered as a possible disinfectant for inhibiting the growth of bacteria in meat (beef cuts and minced pork). Meat cuts were contaminated with two concentrations of L. monocytogenes and S. Typhimurium, as these are the most common meat pathogens that are closely regulated by the EU, and treated with two different concentrations of anolyte: 20% for beef cuts and 18% for minced pork. Then, the total viable count (TVC), L. monocytogenes count and S. Typhimurium count were determined. In meat cuts and minced pork, anolyte was able to reduce TVC, S. Typhimurium and L. monocytogenes counts effectively, significantly decreasing L. monocytogenes and S. Typhimurium counts after spraying and throughout 29 days of incubation at 0–4 °C. TVC was reduced after spraying and for 10 days of incubation but later increased to be the same as before spraying with anolyte. Anolyte was effective when spraying beef cuts with a 20% solution for 60 s against pathogenic bacteria L. monocytogenes and Salmonella spp. and also when using it at a concentration of 18% from the minced meat mass. Initially, anolyte significantly decreased TVC, however during the storage period (10–29 days) TVC increased but remained significantly lower compared to control. Anolyte was effective in reducing L. monocytogenes and S. Typhimurium counts throughout the study, and after 29 days of incubation, these bacteria could not be detected in the samples treated with anolyte.
Article
This study aimed to evaluate the virucidal effect and potential use as a disinfectant of undiluted and diluted slightly acidic electrolyzed water (SAEW) on human noroviruses (HuNoVs) using the in vitro suspension test and in food test. The oxidization reduction potential of SAEW gradually decreased with the increase in distilled water volume. Moreover, as the volume of distilled water and the dilution ratio increased, the available chlorine concentration of the samples significantly decreased from 31.2 ± 0.63 (SAEW) to 1.3 ± 0.21 (1:10 dilution of SAEW solution) (p < 0.05). Undiluted SAEW presented the lowest pH (5.56 ± 0.02) and as SAEW was diluted in distilled water, the pH of the sample increased. Considering the standard reduction values of pathogenic virus (> 4.00 log reduction), the reduction value of HuNoVs in cabbage samples was 4.65 (GI.6) and 4.28 (GII.4) log. These results suggest the potential application of SAEW for inactivating HuNoVs in the food industry. Supplementary information: The online version contains supplementary material available at 10.1007/s10068-021-01011-w.
Article
Acidic and alkaline electrolyzed water (EW) were investigated for their bactericidal effects when sprayed on the surface of beef, chevon (goat meat), and pork inoculated with Escherichia coli K12. Inoculated meat samples were subjected to different treatment times ranging from 2 to 12 min and enumerated on tryptic soy agar to determine the effective log reductions of microbial populations. Acidic EW treated beef, chevon, and pork samples resulted in the highest log reductions of approximately 1.16 (4 min), 1.22 (12 min), and 1.30 log10 CFU/mL (10 min), respectively; and alkaline EW treatments resulted in 1.61, 0.96, and 1.52 log10 CFU/mL reductions at 12 min treatment, respectively. In general, no significant difference in bacterial reduction (p > .05) among the different types of meat was observed. Experimental data were used to fit two microbial reduction models. The Weibull model best described E. coli reduction from meat surfaces. Practical applications Foodborne microorganisms are responsible for a large number of outbreaks and foodborne illnesses. Several conventional methods such as heat and chemicals have been used for many years to ensure the safety of food. Meat is the most consumed food as a source of protein. Since meat is usually marketed raw, chlorine‐based washing technologies are commonly preferred for surface decontamination. However, these technologies may leave some chemical residues in meat that might alter its color, flavor, and texture. Electrolyzed oxidizing water is an alternative nonthermal technology that has been used in recent years to improve the safety of food products. This study thus focuses on determining the efficacy of acidic and alkaline electrolyzed water in inactivating Escherichia coli on beef, chevon, and pork surfaces.
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Objective: To evaluate the effect of the combination of calcium hydroxide (Ca(OH)2) and a novel electrolyzed superoxidized solution at neutral pH, known as OxOral® on Enterococcus faecalis growth in root canals. Methods: Sixty human teeth were used, from which root canals were infected and randomly divided into the following treatment groups: saline solution, saline solution plus Ca(OH)2, OxOral®, and OxOral® plus Ca(OH)2. Results: A permanent reduction in bacterial growth was observed at days 1, 6, 12, and 18 after OxOral® plus Ca(OH)2 treatment from 4.4 ± 0.074 log10 CFU/mL to 0.0 ± 0.001 log10 CFU/mL. In addition, alkaline conditions maintenance was observed from application time (pH = 12.2 ± 0.033) to 18 d posttreatment (pH = 12.6 ± 0.083). Conclusion: The combination of OxOral® and Ca(OH)2 provides an alkaline pH and inhibits E. faecalis growth into the root canals. Our study opens the possibility for further research on the use of OxOral® in endodontic therapy.
Article
The use of electrolyzed oxidizing (EO) water to inactivate microorganisms on foods has been extensively studied and shown to be effective. However, the prospect of the formation of “viable but nonculturable” (VBNC) cells in pathogens after low free chlorine concentration (FCC) treatments under high organic loads presents safety concerns. This study investigated the effect of EO water FCC on inducing Escherichia coli O157:H7 and Listeria monocytogenes into the VBNC state and studied possible resuscitation triggering procedures of the VBNC cells. A 5‐strain cocktail of each pathogen (10⁶ colony forming units [CFU]/mL) was exposed to EO water (FCC of 20, 10, 5, 2.5, 1.25, 0.625 mg/L) and allowed to stand for 1 and 5 min, followed by the addition of neutralizing broth. Treated samples were plated on nonselective agar and analyzed using flow cytometry. For resuscitation, samples treated with identified VBNC induction conditions were exposed to elevated temperatures (37 °C) as well as addition of sodium pyruvate (SP) and Tween® 20 (T20) solutions. The initial culturing procedures suggested complete inactivation of both pathogens at 2.5 and 1.25 mg/L FCC in the growth medium. However, flow cytometry profiles showed VBNC cells were present. Subjecting samples to the recovery procedures further proved that VBNC E. coli O157:H7 can be resuscitated after exposure to SP and T20 at 37 °C, while L. monocytogenes did not resuscitate. These findings show that treating pathogens at low FCC can induce the VBNC state, and culturability of E. coli O157:H7 can be restored under appropriate conditions. Practical Application VBNC induction conditions for foodborne pathogens during chlorine washing treatment were determined in a broth system and the information can serve as a basis for future studies that address the prevention of VBNC formation during produce wash treatments.
Article
Objective To compare the antimicrobial efficacy of a 2% chlorhexidine gluconate and 70% ethanol solution (CG+A) with that of F10 Skin Prep Solution (F10) and electrochemically activated water (EAW) when used as a surgical preparation in canine patients. Study design Prospective randomized clinical study. Sample population One hundred sixteen dogs presented for ovariohysterectomy. Methods Dogs were randomly divided into 1 of the 3 antiseptic groups (CG+A, F10, EAW). Skin samples with replicating organism detection and counting plates were taken at 4 different perioperative sites and time intervals (postskin preparation, postskin antisepsis, 2 hours after the second sample, and at the end of surgery) during ovariohysterectomies performed by students. The colony forming unit (CFU) counts from each sample were quantified according to the level of bacterial contamination. Zero CFU was defined as no contamination, 1‐12 CFU was defined as low contamination, and greater than 12 CFU was defined as high contamination. The 3 antiseptics were compared with respect to the level of contamination. Results There was no difference in the level of colonization between the antiseptics at the first sampling time (P = .454). However, the level of contamination for CG+A was lower compared with F10 and EAW at the second, third, and fourth sampling times (P = .001, P = .01, P = .02, respectively). Conclusion CG+A was more effective at achieving a zero CFU count and low levels of contamination compared with F10 and EAW for surgical preparation in dogs undergoing ovariohysterectomy. Clinical significance This study does not provide evidence to support the use of F10 and EAW instead of CG+A for the surgical skin preparation of dogs undergoing ovariohysterectomy.
Article
In this current study, comparative study between the effect of electrolyzed water and ultrapure water on the extraction of apricot protein was conducted. The results revealed that under the condition of same pH (pH = 9.5), the extraction efficiency of electrolyzed water on apricot protein was superior to that of ultrapure water. Moreover, apricot protein (EAP) extracted by electrolyzed water displayed preferable foaming capacity and emulsion stability. The foaming capacity and emulsion stability of EAP were 11.17% and 36.33 min, for UAP, only 4.75% and 23.88 min, respectively. Meanwhile, compared to UAP, the secondary structure of EAP was more orderly, in which the orderly structures of α-helix and β-sheet were 7.5 and 60.2%, while the disorderly structures of β-turn and random coil were 8.4 and 23.8%. This work provided a novel extraction strategy, which could improve the extraction rate and minimize the destruction of the structure and functional properties of apricot protein.
Article
Bactericidal activity of neutral electrolyzed water (NEW) was investigated against endospore forming Bacillus cereus and Clostridium perfringens in cell suspensions and artificially inoculated onto the surface of selected fresh produce items (cherry tomato, miniature cucumber, carrot and parsley) and polypropylene cutting boards at ambient temperature (22 °C). Viable counts of survivors were determined within 0 (untreated control), 1, 3 and 5 min of treatment at ambient temperature using NEW solutions of 60 and 120 mg/L free available chlorine FAC. All treatments showed significant differences (P < 0.05) in bacterial reductions with regard to contact time and concentration used and which maximized after 5 min of treatment at 120 mg/L FAC. For cell suspensions, the extent of reduction (log10 CFU/mL) after 5 min of treatment ranged from 2.11 to 3.03 for B. cereus and 2.46–3.62 for C. perfringens at 60 and 120 mg/L FAC, respectively. However, when the bacteria inoculated onto the produce items and cutting boards showed greater resistance to NEW treatments compared to cell suspensions. Sterile deionized water did not contribute any significant reduction (P > 0.05) after 5 min of treatment, whereas bacterial viability of the inoculated produce was reduced by 2.11–2.30 and 2.41–3.16 log10 CFU/g when NEW used at 120 mg/L FAC for B. cereus and C. perfringens, respectively. When inoculated cutting boards were sprayed with NEW at 120 mg/L FAC and after 5 min of treatment, cell viability was reduced by 2.33 and 3.06 log10 per 100 cm² for B. cereus and C. perfringens, respectively. This study showed that NEW could be used as an effective bactericidal treatment alternative to commonly used chemical sanitizers against endospore forming bacteria.
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A novel protein extraction method of ultrasound-assisted basic electrolyzed water (BEW) was proposed, and its effects on the structural and functional properties of Antarctic krill proteins were investigated. Results showed that BEW reduced 30.9% (w/w) NaOH consumption for the extraction of krill proteins, and its negative redox potential (−800 ~ −900 mV) protected the active groups (carbonyl, free sulfhydryl, etc.) of the proteins from oxidation compared to deionized water (DW). Moreover, the ultrasound-assisted BEW increased the extraction yield (9.4%), improved the solubility (8.5%), reduced the particle size (57 nm), favored the transition of α-helix and β-turn to β-sheet, promoted the surface hydrophobicity and disulfide bonds formation of krill proteins when compared to BEW without ultrasound. These changes contributed to the enhanced foam capacity, foam stabilityand emulsifying capacity of the krill proteins. Notably, all the physicochemical, structural and functional properties of the krill proteins were comparable to those extracted by the traditional ultrasound-assisted DW. This study suggests that the ultrasound-assisted BEW can be a potential candidate to extract proteins, especially offering an alternative way to produce marine proteins with high nutritional quality.
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Percutaneous needle electrolysis (PNE) is a physiotherapy technique that has been shown to be effective in different pathologies such as tendinopathies or mammary fistula. For many years, theoretical bactericidal and germicidal effects have been attributed to this type of galvanic currents, partly explained by the changes in pH that it generates. However, these effects have not yet been demonstrated. The aim of this study was to evaluate the bactericidal effect and the changes in pH caused by PNE. S. aureus were prepared in two different solutions (TSB and saline solution) and in different concentrations (from 9 to 6 Log10 CFU/mL). Bacteria were treated with three experimental PNE doses to assess bacterial death levels and the changes caused to the pH of the medium. The viable cell count showed that all experimental PNE doses had a bactericidal effect against a high concentration (9 Log10 CFU/mL) of S. aureus in saline solution (p < 0.001). Furthermore, we found that when the concentration of bacteria decreased, a lower dose of galvanic current generated the same effect as a higher dose. Changes in pH were registered only in experiments performed with saline solution. PNE had a bactericidal effect against S. aureus and the level of this effect was mainly modulated by the solution, the bacterial concentration and the dose. Changes affecting pH were modulated by the type of solution and there was no relationship between this and bacterial death.
Chapter
Electrolyzed water (EW) considered as a novel broad-spectrum and high-performance bactericide has gained immense popularity over the last few decades. It offers several advantages over other sanitizers for sanitation of both food contact and noncontact surfaces, such as safety, effective disinfection, easy operation, relatively inexpensive, and environmentally friendly. EW can be produced by electrolyzing soft tap water with sodium chloride as the chemical additive. Different producing equipment and parameters greatly influence the types and properties of EW. During production period, preparation settings are vital factors on the basic properties of EW (available chlorine concentration (ACC), pH, and oxidization reduction potential (ORP)) and then influence its inactivation efficiency, including current, water flow rate, salt/acid concentration, electrolyte and electrode, water temperature and hardness, storage environments, and so on. This chapter provides an overview of the production, properties, types of EW, as well as a section on its advantages and disadvantages.
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Foods of animal origin, such as red meat and poultry products, are primary sources of superior protein for humans. With the production and consumption of these products increasing rapidly in recent decades, microbial safety and food quality are vital issues. Electrolyzed water (EW) as a sanitizer has awakened high interest in the food industry of many countries. The use of EW to decontaminate fresh red meat, ready-to-eat meat, poultry and shell eggs has been effective in reducing pathogenic microorganisms. Moreover, EW presents many advantages over traditional decontaminants; it provides effective antimicrobial activity and is environmentally friendly, simple to handle and relatively inexpensive. However, no complete elimination of pathogens on red meat and chicken meat was obtained after treatment of the meats with EW. This result probably occurs because organic matter and blood residue were present. This chapter provides a brief overview of how EW treatment affects foods of animal origin, especially the microbial safety and the physicochemical and sensory qualities of the food.
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Electrolyzed water is a safe, broad-spectrum bactericidal and viricidal agent, which can be used as a potent and effective alternative disinfectant in case of supply shortages. This report describes the on-site production of slightly acidic electrolyzed water (EW) from diluted salt solution and vinegar at a dental office using a portable EW generator unit. Such measures can ensure the safe continuity of important dental service provision for our patients during the coronavirus disease 2019 (CoVID-19) pandemic.
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Cassava starch was oxidized using the electrolysis system. Sodium chloride was added to this system at various concentrations from 0.5 to 5.0 % (w/v). The whiteness of modified starches proportionally increased based on the NaCl concentration and human eyes could recognize the difference of color. Under treatment, dents occurred on the surface of starch granule. Concentration of carbonyl and carboxyl groups was increased compared to native starch. Based on X-ray diffraction pattern, oxidized starch kept its A-type. Besides, the ratios of alpha-helix/amorphous regions remained indicating oxidation reaction mainly subjected on amorphous region. Intrinsic viscosity was used to indirectly calculate the average molecular weight of sample. Furthermore, results showed that average molecular weight was significantly reduced (from 2.09-fold to 13.22-fold) based on the reacting NaCl concentration. The increase of NaCl content related to the increase of retrogradation of treated starches. At various temperatures (30-95°C), swelling factor and clarity reflected negative and positive correlations to NaCl concentration.
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Electrolyzed oxidizing water (EOW) is one of the promising novel antimicrobial agents that have recently been proposed as the alternative to conventional decontamination methods such as heat and chemical sanitizers. Acidic EOW with pH ranging from 2 to 5 is regarded most applicable in the antimicrobial treatment of vegetables and meats. Neutral and alkaline electrolyzed water have also been explored in few studies for their applications in the food industry. Neutral electrolyzed water is proposed to solve the problems related to the storage and corrosion effect of acidic EOW. Recently, the research focus has been shifted toward the application of slightly acidic EOW as more effective with some supplemental physical and chemical treatment methods such as ultrasound and UV radiations. The different applications of electrolyzed water range from drinking water and wastewater to food, utensil, and hard surfaces. The recent studies also conclude that electrolyzed water is more effective in suspensions as compared with the food surfaces where longer retention times are required. The commercialization of EOW instruments is not adopted frequently in many countries due to the potential corrosion problems associated with acidic electrolyzed water. This review article summarizes the EOW types and possible mechanism of action as well as highlights the most recent research studies in the field of antimicrobial applications and cleaning. Electrolyzed water can replace conventional chemical decontamination methods in the industry and household. However, more research is needed to know its actual mechanism of antimicrobial action along with the primary concerns related to EOW in the processing of different food products.
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Ionised active water S-100® has been proposed as an original solution for use in dermocosmetics and for the treatment of wounds such as burns and atopic dermatitis. Among the mechanisms of action that are not completely understood, an antimicrobial activity would appear to be important. In the context of the COVID-19 pandemic, we assessed the inactivating efficacy of this solution on SARS-CoV-2 based on the recommendations of the NF-EN-14476+A2 standard. The tests carried out demonstrated that ionised active water S-100® 40% has a virucidal activity on SARS-CoV-2 which is at least 3.1 log after a contact time of 30 seconds and 3.5 log after two minutes at 20°C under clean conditions. Assays were also performed at 4°C and 37°C, and the results obtained are identical to those obtained at 20°C. This demonstration of the virucidal effect of ionised water against SARS-CoV-2 paves the way for the development of usage as an alternative disinfectant in SARS-CoV-2 control.
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As the situation of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is still deteriorating, there has been a huge increase in the demand and use of disinfectants. Electrolyzed water (EW), as a novel broad-spectrum disinfectant and cleaner, has been widely used for several years. EW can be produced in an electrolysis chamber which contains dilute salt and tap water. It is an effective antimicrobial and antibiofilm agent, with several advantages such as on-the-spot, cheap, environmentally friendly and safe for human beings. Therefore, EW holds potential significance for high-risk settings in hospitals and other clinical facilities. EW can also be applied for wound healing, advanced tissue care, and dental clinics. The present review article highlights the latest developments and new perspectives of EW, especially in clinical fields. Furthermore, the main action modes of antibiofilm and antimicrobial will be summarized.
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Disinfection after harvest is an essential step to maintain commodities and facilities free of fungal and bacterial postharvest pathogens, responsible of storage decay and economic losses. Electrolyzed water (EW) has gained considerable interest over the last decades as a novel broad-spectrum sanitizer. EW is sustainable and cost effective since it can be produced on-site utilizing tap water and different inexpensive salts and is healthy for both the environment and human beings. Its effectiveness in controlling fungi, yeasts, and bacteria within a wide range of pH is due to multiple mode of actions. Furthermore, its strong oxidizing potential is capable to reduce the amount of pesticide residues on fruit and vegetable surfaces and to avoid pathogen resistance. Properties of EW are related to salts employed for production, being those with low chlorine content preferable. Lastly, EW has no negative effect on the organoleptic properties and features of treated commodities. The present chapter highlights recent developments in EW generation, factors affecting its effectiveness for controlling postharvest decay of fruits and vegetables, mechanism of action on microbes and hosts, and advantages and disadvantages on its use.
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There is increasing demand for safe and effective sanitizers for irrigation water disinfection to prevent transmission of foodborne pathogens to fresh produce. Here we compared the efficacy of pH-neutral electrolyzed oxidizing water (EOW), sodium hypochlorite (NaClO) and chlorine dioxide (ClO2) against single and mixed populations of E. coli, Listeria and Salmonella under a range of pH and organic matter content. EOW treatment of the mixed bacterial suspension resulted in a dose-dependent (<1 mg/L free chlorine), rapid (<2 min) and effective (4–6 Log10) reduction of the microbial load in water devoid of organic matter under the range of pH conditions tested (pH, 6.0, 7.0, 8.4 and 9.2). The efficacy of EOW containing 5 mg/L free chlorine was unaffected by increasing organic matter, and compared favourably with equivalent concentrations of NaClO and ClO2. EOW at 20 mg/L free chlorine was more effective than NaClO and ClO2 in reducing bacterial populations in the presence of high (20–100 mg/L) dissolved organic carbon, and no regrowth or metabolic activity was observed for EOW-treated bacteria at this concentration upon reculturing in rich media. Thus, EOW is as effective or more effective than other common chlorine-based sanitizers for pathogen reduction in contaminated water. EOW’s other characteristics, such as neutral pH and ease of handling, indicate its suitability for fresh produce sanitation.
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The demand of lactulose production is increasing tremendously because of its bifidogenic (prebiotic) functionality. Therefore, the isomerization of lactose to synthesize lactulose through electroactivation (EA) technology is of great interest nowadays. However, lactulose production through electroisomerization is affected by several operational and experimental conditions, and the process needs to be optimized. In this context, the EA technique was applied to isomerize lactose into lactulose in an EA reactor modulated by anion and cation exchange membranes. The effect of lactose concentrations (5, 10, 15, and 20%), applied electric fields (300, 600, and 900 mA), and processing time (0–60 min) on lactose electroisomerization rate (lactulose formation) and coproduct (glucose, galactose, and fructose) formation has been investigated. The effect of different physicochemical parameters such as pH, alkalinity, temperature, ion migration, and oxidation–reduction potential (ORP) on the conversion of lactose into lactulose was correlated with the lactulose formation to understand the involved process mechanism of action. The conversion of lactose into lactulose was lactose-concentration-, electric-current-, and EA-time-dependent and reached the highest lactulose yield of 38% at 40 min using a 900 mA current intensity in a 10% lactose solution. The results were then compared to conventional chemical isomerization maintaining similar alkaline conditions at ambient temperature (22 ± 2 °C). A higher yield of lactulose was achieved in the EA process within a short reaction time compared to that of the chemical isomerization. The outcome of this study suggests that EA is a promising technique for the enhanced production of lactulose from lactose.
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The prevention of nosocomial infections is an imperative task. The dental chair unit (DCU) is an indispensable device used in dental treatment. However, it is known that the dental unit water line (DUWL) can become contaminated with biofilm, consisting mainly of heterotrophic bacteria (HB). Recently, the International Organization for Standardization specified the methods for testing DUWL contamination management. On these grounds, a simulator reproducing DUWL was prepared to standardize the examination method of the DUWL contamination. Objectives To evaluate the reproducibility of the DUWL simulator, monitor the DUWL contamination states, and test the efficacy of a commercial decontaminant for DUWL. Methods The DUWL simulator was assembled by a DCU manufacturing company. The simulator's DUWL was filled with tap water (TW), and left for approximately one year. Neutral electrolyzed water (NEW) was used as a decontaminant for DUWL. Both TW and NEW were passed through DUWL in a timely manner simulating daily dental treatment. Water was sampled from the air turbine hand piece weekly for 4 weeks and used for HB culture. Contamination status was evaluated by measuring bacterial adenosine triphosphate release and by culturing on Reasoner's 2A medium. Results The DUWL released contaminated water had a bacterial count of over 6 × 10⁴ cfu/mL. After passing NEW through DUWL for 1 week, the count drastically decreased to its basal level and remained steady for 4 weeks. However, TW showed no effect on DUWL decontamination throughout the examination periods. Conclusions The DUWL simulator could be useful to examine the efficacy of the decontaminant for DUWL and development of new methods in DUWL contamination management.
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The disinfection efficiencies of two chemical disinfectants, chlorine dioxide and weak acid hypochlorous water (WAHW), were examined in the soiled room and dishwashing room of a hospital infectious disease ward in Taiwan. The investigations were conducted in two seasons, namely winter and summer, in order to examine the correlation between the bioaerosol concentration and the environmental factors. In addition, a single-daily disinfection mode (SM) and a twice-daily disinfection mode (TM) were applied in this study. The results showed that the bacteria and fungi colony counts were strongly correlated with the temperature. Both disinfectants reduced the bacteria and fungi concentrations in the considered rooms. However, of the two disinfectants, the ClO2 showed a stronger disinfection effect than the WAHW. It means that when using ClO2 as the disinfectant, the disinfection efficiency of the TM treatment mode is significantly better than that of the SM treatment mode. But, when using WAHW as the disinfectant, no significant difference is found between the disinfection efficiencies of the two methods. Overall, the results showed that the application of ClO2 twice daily provided the most effective means of satisfying the Taiwan EPA guidelines for the indoor air quality of hospital medical wards.
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In the last decade, outbreaks linked to the consumption of contaminated fresh produce have increased mitigation efforts to minimize the risks associated with these products. Due to the lack of a kill step during processing of ready-to-eat (RTE) foods, good manufacturing practices (GMP’s), and sanitization are the key prevention areas most commonly used to control these risks. Many factors must be considered by processors for successful intervention such as sanitizer type, method of application, duration of application, and concentration. Additionally, product considerations such as water content, pH, and bacterial harborage sites can contribute greatly to how effective an applied treatment may be. The goal of this research was to evaluate alternative sanitization methods at the pilot scale to combat Listeria innocua and native microflora on fresh cut cantaloupe and wild blueberries. Parameters chosen for these studies aimed to mimic current processing conditions to provide a better understanding of what you likely would see in a large-scale processing environment. To carry out this research, a bench scale study was completed to determine which treatment combinations to use at the pilot scale. Sequential applications of chlorine (200ppm), peracetic acid (PAA, 80ppm), and electrolyzed water (200ppm active chlorine constituents) were compared to a water control. The combination of sanitizer treatments were applied via dip or spray singly, or sequential application of dip then spray, or duplicate spray. At the pilot scale, sanitizer combination treatments were evaluated for 3 minutes of contact time followed by freezing for up to two weeks (wild blueberries) or refrigerated storage for 48 hours (fresh cut cantaloupe). Microbial populations were evaluated at each stage to determine the efficacy of each treatment. For fresh cut cantaloupe we found that none of the treatments investigated were effective at reducing Listeria innocua populations at the pilot scale and observed an increase in population following refrigerated storage. Similarly, for wild blueberries none of the treatments investigated significantly reduced Listeria innocua populations and after two weeks of freezing Listeria innocua was detected in the product. Our results demonstrate the complex interaction of the treatment applied and product type, volume of product, and application method. Understanding these interactions can help processors to make informed decisions for potential food safety interventions and the applicability of current research at the pilot scale. Further investigation into the effects of growing practices on microbial communities and other potential pathogen inactivation methods need to be evaluated.
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Microbial control of postharvest diseases has been extensively studied and appears to be a viable technology. Food safety must be ensured at each postharvest processing step, including handling, washing of raw materials, cleaning of utensils and pipelines, and packaging. Several commercial products are available for this purpose. The time is ripe for developing new techniques and technologies. The use of electrolyzed water (EW) is the product of a new concept developed in Japan, which is now gaining popularity in other countries. Little is known about the principle behind its sterilizing e#ect, but it has been shown to have significant bactericidal and virucidal and moderate fungicidal properties. Some studies have been carried out in Japan, China, and the USA on the pre-and postharvest application of EW in the field of food processing. EW may be produced using common salt and an apparatus connected to a power source. As the size of the machine is quite small, the water can be manufactured on-site. Studies have been carried out on the use of EW as a sanitizer for fruits, utensils, and cutting boards. It can also be used as a fungicide during postharvest processing of fruits and vegetables, and as a sanitizer for washing the carcasses of meat and poultry. It is cost-e#ective and environment-friendly. The use of EW is an emerging technology with considerable potential.
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The adherence and viability of Escherichia coli inoculated onto the surfaces of plastic cutting boards and new and used wood cutting boards were evaluated. Most of the inoculum was recovered from all surfaces after resident drying times of 5 min and from plastic surfaces at 24 h. When the exposure time was extended to 2 h, > 90% of the cells placed on new and used dry wood surfaces were not recovered after vigorous rinsing. Scanning electron microscopy showed that the bacteria resided within the structural xylem fibers and vegetative elements of the wood. After resident drying times of up to 2 h, almost 75% of the adherent bacteria on the wood surfaces were viable, as defined by a nalidixic acid direct viable count procedure. Microcosm studies showed no intrinsic growth-supporting or toxic properties of the cutting board materials. Bacteria that adhered to plastic surfaces were more easily removed by low-temperature washing than were cells that adhered to wood surfaces. These studies demonstrated that bacteria adhering to wood surfaces resided within the structural and vegetative elements of the wood's xylem tissues and were viable; wood was more retentive than plastic; penetration of the inoculum liquid promoted cell adherence to the wood matrix; and conditioning of wood with water before inoculation interfered with bacterial adherence.
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Spores of Penicillium expansum, the primary organism responsible for the occurrence of patulin in apple juice, were exposed to electrolyzed oxidizing (EO) water in an aqueous suspension and on wounded apples. Full-strength and 50% EO water decreased viable spore populations by greater than 4 and 2 log units, respectively. Although EO water did not prevent lesion formation on fruit previously inoculated with P. expansum, cross-contamination of wounded apples from decayed fruit or by direct addition of spores to a simulated dump tank was substantially reduced. EO water, therefore, has potential as an alternative to chlorine disinfectants for controlling infection of apples by P. expansum during handling and processing operations.
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The efficacy of electrolyzed oxidizing (EO) and acidified chlorinated water (45 ppm residual chlorine) was evaluated in killing Escherichia coli O157:H7 and Listeria monocytogenes on lettuce. After surface inoculation, each leaf was immersed in 1.5 L of EO or acidified chlorinated water for 1 or 3 min at 22 °C. Compared to a water wash only, the EO water washes significantly decreased mean populations of E. coli O157:H7 and L. monocytogenes by 2.41 and 2.65 log10 CFU per lettuce leaf for 3 min treatments, respectively (p < 0.05). However, the difference between the bactericidal activity of EO and acidified chlorinated waters was not significant (p > 0.05). Change in the quality of lettuce subjected to the different wash treatments was not significant at the end of 2 wk of storage.
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Glutaraldehyde is used as a disinfectant for endoscopes, but is an irritant and so should be replaced by an alternative. Electrolysed acid water (EAW) has a bactericidal effect, and an endoscopic washing device using EAW has been developed in Japan. To investigate the effect of EAW on the infectivity of viruses, we treated duck hepatitis B virus (DHBV), which has similar properties to hepatitis B virus, with EAW, and determined the number of remaining infectious virus particles in a bioassay system. One-day-old Pekin ducks were inoculated with duck serum containing 105.5 ID 50 DHBV; the serum had previously been incubated with 100 volumes of EAW or ion-exchanged water at room temperature for 7 min. DHBV infection was indicated by detection of viral DNA in duck serum samples 1–8 weeks after inoculation. Treatment of serum with EAW diminished DHBV infectivity whereas treatment with ion-exchanged water did not. The virus load was estimated to have been reduced to 101–103 ID 50 during the first 1 min and to <100.5 ID 50 in the next 6 min of incubation when compared with the control. Thus, EAW directly inactivates DHBV and its clinical application is recommended.
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The efficacy of 14 disinfectants against Listeria innocua and two strains of Listeria monocytogenes in the presence of organic matter was studied. Quantitative efficacy tests were used. Many of the disinfectants tested were not as effective on Listeria spp. when the test organisms were dried onto the surface of steel disks (carrier tests) as they were when the organisms were placed in suspension (suspension test). The presence of whole serum and milk (2% fat) further reduced the disinfectant capacities of most of the formulations studied. Only three disinfectants (povidone-iodine, chlorhexidine gluconate, and glutaraldehyde) were effective in the carrier test in the presence of serum; however, all three were ineffective when challenged with milk (2% fat). Only one solution, sodium dichloroisocyanurate, was effective in the presence of milk. All but four formulations (chloramine-T, phosphoric acid, an iodophor, and formaldehyde) were effective in the suspension tests, regardless of the organic load. L. monocytogenes was observed to be slightly more resistant to disinfection than L. innocua was. There was no difference in disinfectant susceptibility between the two strains of L. monocytogenes. These findings emphasize the need for caution in selecting an appropriate disinfectant for use on contaminated surfaces, particularly in the presence of organic material.
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Transient chlorine concentration profiles were measured in biofilms during disinfection by use of a microelectrode developed for this investigation. The electrode had a tip diameter of ca. 10 microm and was sensitive to chlorine in the micromolar range. The biofilms contained Pseudomonas aeruginosa and Klebsiella pneumoniae. Chlorine concentrations measured in biofilms were typically only 20% or less of the concentration in the bulk liquid. Complete equilibration with the bulk liquid did not occur during the incubation time of 1 to 2 h. The penetration depth of chlorine into the biofilm and rate of penetration varied depending on the measurement location, reflecting heterogeneity in the distribution of biomass and in local hydrodynamics. The shape of the chlorine profiles, the long equilibration times, and the dependence on the bulk chlorine concentration showed that the penetration was a function of simultaneous reaction and diffusion of chlorine in the biofilm matrix. Frozen cross sections of biofilms, stained with a redox dye and a DNA stain, showed that the area of chlorine penetration overlapped with nonrespiring zones near the biofilm-bulk fluid interface. These data indicate that the limited penetration of chlorine into the biofilm matrix is likely to be an important factor influencing the reduced efficacy of this biocide against biofilms as compared with its action against planktonic cells.
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Surveys were made of commercial processing lines used to prepare fresh-cut vegetables such as chopped salad ingredients, carrot sticks, and cauliflower florets. Washing and chlorinated water dips only partially removed the microorganisms that were intrinsic to the vegetables. Major sources of in-plant contamination were the shredders used to prepare chopped lettuce and coleslaw. Gram-negative rods were the predominant microflora with species of Pseudomonas being most numerous; many were psychrotrophic. Only low numbers of lactic acid bacteria and fungi were recovered. Copyright © International Association of Milk, Food and Environmental Sanitarians.
Article
The disinfectant effect of acidic electrolyzed water (AcEW), ozonated water, and sodium hypochlorite (NaOCl) solution on lettuce was examined. AcEW (pH 2.6; oxidation reduction potential, 1140 mV; 30 ppm of available chlorine) and NaOCl solution (150 ppm of available chlorine) reduced viable aerobes in lettuce by 2 log CFU/g within 10 min. For lettuce washed in alkaline electrolyzed water (AlEW) for 1 min and then disinfected in AcEW for 1 min, viable aerobes were reduced by 2 log CFU/g. On the other hand, ozonated water containing 5 ppm of ozone reduced viable aerobes in lettuce 1.5 log CFU/g within 10 min. It was discovered that AcEW showed a higher disinfectant effect than did ozonated water significantly at P < 0.05. It was confirmed by swabbing test that AcEW, ozonated water, and NaOCl solution removed aerobic bacteria, coliform bacteria, molds, and yeasts on the surface of lettuce. Therefore, residual microorganisms after the decontamination of lettuce were either in the inside of the cellular tissue, such as the stomata, or making biofilm on the surface of lettuce. Biofilms were observed by a scanning electron microscope on the surface of the lettuce treated with AcEW. Moreover, it was shown that the spores of bacteria on the surface were not removed by any treatment in this study. However, it was also observed that the surface structure of lettuce was nor damaged by any treatment in this study. Thus, the use of AcEW for decontamination of fresh lettuce was suggested to be an effective means of controlling microorganisms.
Article
The efficacy of Electrolysed Oxidising Water (EOW) for inactivating spoilage microorganisms in process water and on minimally processed vegetables was investigated. The direct effect of EOW on three important spoilage bacteria namely; Pseudomonas fluorescens, Pantoea agglomerans or Rahnella aquatilis was determined by inoculating tap water or "artificial process water" with approximately 8 log CFU/ml pure culture and electrolysing the resultant solutions. The three bacteria were each reduced to undetectable levels at low (0.5 A) and relatively higher levels (1.0 A) of current in tap water and "artificial process water". respectively. The residual effect of EOW on P fluorescens, P agglomerans or R. aquatilis was determined by incubating at room temperature 1 ml (approximately 9 log CFU/ml) pure culture suspensions in 9 ml of EOW-T (EOW produced from tap water), EOW-A (EOW produced from "artificial process water" supplemented with approximately 60.7 mg Cl-/l and 39.3 mg Na+/l) or deionised water (control) for 0, 15 45 or 90 min. The bactericidal activity of both EOW-T and EOW-A increased with the concentration of free oxidants and incubation period and the three bacteria were completely reduced at free oxidants-incubation period combinations of 3.88 mg/1-45 min and 5.1 mg/1-90 min in EOW-T and EOW-A, respectively. Two types of industrial vegetable process water; salad-mix and soup process water, which had each a total psychrotrophic count of approximately 8 log CFU/ml were then electrolysed. Without any NaCl addition, only 1.2 and 2.1 log reductions of the psychrotrophs in soup and salad-mix process water was attained respectively. Supplementation of the process water with approximately 60.7 mg Cl-/l and 39.3 mg Na+ /l afterwards resulted in complete reduction of the psychrotrophic count in both process waters, but soup process water required relatively higher levels of current compared to salad-mix water. Finally, fresh-cut lettuce was washed in EOW-T containing 3.62 mg free oxidants/l, EOW-IP (EOW produced from industrial process water) containing 2.8 mg free oxidants/l or tap water (control) for 1 or 5 min. Washine the vegetables for 1 min in EOW-T resulted in 1.9, 1.2, and 1.3 log reductions of psychrotrophs, lactic acid bacteria and Enterobacteriacae, respectively, which increased to 3.3, 2.6, and 1.9 log reductions after washing for 5 min instead. EOW-IP tested in this work had no bactericidal effect on the microflora of fresh-cut lettuce. Electrolysis could therefore be used to decontaminate process water for vegetable pre-washing and to sanitise tap water for final rinsing of vegetables, respectively. (c) 2006 Elsevier B.V. All rights reserved.
Article
Inactivation by hypochlorite of Listeria monocytogenes cells adherent to stainless steel was determined. Adherent cell populations were prepared by incubating stainless steel slides with a 24 h culture of L. monocytogenes for 4 h at 21°C. Adherent microcolonies were prepared by growing L. monocytogenes on stainless steel slides submerged in a 1:15 dilution of tryptic soy broth at 21°C. The slides were then rinsed and transferred to fresh sterile broth every 2 d with a total incubation time of 8 d. Although the 4 h and 8 d adherent populations were at similar levels, 8 d adherent cells were over 100 times more resistant than the 4 h adherent cell population when exposed to 200 ppm hypochlorite for 30 s. When stainless steel slides containing adherent cells were heated at 72°C both adherent cell populations were inactivated after 1 min. Detectable numbers of L. monocytogenes remained on stainless steel slides after treatment at 65°C for 3 min when adherent 8 d cells were tested but not when adherent 4 h cells were used. Copyright © International Association of Milk, Food and Environmental Sanitarians.
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Electrolyzed water (EW) has attracted much recent attention as a high-performance, new technology for potential use in the food industry. However, this is the first review which examines the potential of the antimicrobial effect of electrolyzed water solutions in many different food models such as vegetable, fruits, meat, poultry, fish, and other products. Production, theoretical of the chemical reactions in the production of EW, theories of disinfectant effect of EW and advantage of using EW would be reviewed. The purpose of this review is to introduce simple information about the use of this new technology in the field of food disinfection, for both readers and food industry.
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Recently, several reports about sterilization effect of electrolyzed water have been published. The electrolyzed water is expected as one of attractive application for sanitation of fresh food, however, to install this electrolyzed water, we have to clear the potential of the microorganism control for real food. In this paper, we try to reveal the mechanism of the microorganism control, and also try to check the food quality change during the treatment. Therefore, to evaluate the effect of the electrolyzed water, we examined the several test for making sterilization mechanism clear and observed microorganism behavior on food surface. At first, for the purpose of making sterilization effects clear in vitro condition, we did microorganism test with several injection ratio and number. Then, we studied the effects of catalase on the enumeration of stressed Escherichia coli cells after acidic electrolyzed water treatment. Moreover, we studied sterilization effect of acidic electrolyzed water for E. coli on an agar block on the assumption as one of food model. In addition, we studied sterilization effects for sliced raw tuna as one sample of food surface treatment. The change in the quality of food surface was observed by scanning electron microscope, color meter and so on. Sterilization effects are dependent the condition of injection ratio and mixing numbers. These results suggest that it is important to keep available chlorine concentration for keeping the potential to the microorganisms' control. The increasing of E. coli number with the addition of catalase was suggested that the weak concentration of electrolyzed water gave the injured microbes. The Observation of cultivated E. coli behavior on agar block showed the microorganism behavior. Acidic electrolyzed water sterilizes microorganisms on sliced raw tuna, however, after treatment, the color change of surface of tuna and the protein denaturation were observed. These results suggest that when the electrolyzed water treatment is applied to control the microorganism on surface, the effectagainst food surface must be considered.
Article
The main factor contributing to the disinfecting potential of acidic electrolyzed water (AcEW) is deduced to be the oxidizing power of available chlorine. In this study, we compared the reliability of two different methods for measuring the available chlorine concentration (ACC). Several AcEW solutions with different levels of ACC to which various reducing agents (ascorbic acid, ammonium iron (II) sulfate, and iron (II) chloride) had been added were prepared. These ACC levels were quantified by iodometry and the DPD (N, N-diethyl-p-phenylenediamine) method. In the case of AcEW with iron (II) ions, iodometry did not show the correct ACC. On the other hand, the DPD method correctly quantified ACC even in the case of AcEW with iron (II) ions. Thus, the DPD method is an appropriate method for measuring ACC in AcEW. Moreover, we investigated the effect of the available chlorine concentration (ACC) in AcEW on its disinfecting potential. First, we examined the disinfectant effects of AcEW on shredded vegetables. We found that there was no difference in the disinfectant effects between AcEW with high ACC (40 ppm) and low ACC (0.4 ppm). The similar effect was detected in AcEW with 0 ppm of ACC, a solution that seemed to be the same as hydrochloric acid. Moreover, tap water with pH adjusted to 2.4 showed the same disinfectant effect as that of AcEW. These results indicated that AcEW is a solution in which available chlorine is activated in a low pH condition. Next, we examined the disinfectant effects of AcEW on a suspension obtained from shredded vegetables in vitro. The disinfecting potential became weaker, but did not completely disappear, when ACC was reduced to O ppm. Thus, AcEW with low ACC could be used to disinfect shredded vegetables, although the disinfecting potential of AcEW would become weak. When the effective concentration of Ace was examined, it was found that the AcEW with ACC of less than 20 ppm did not have sufficient disinfectant potential. Moreover, it was found that high ORP (above 1000 mV) does not contribute to disinfecting potential. Thus, the lower limit of ACC in AcEW for AcEW to exert a sufficient disinfectant effect will be 20 ppm.
Article
Electrolyzed Water (Acidic Electrolyzed Water, Alkaline Electrolyzed Water) has recently attracted the interest of researchers in various fields such as medicine, agriculture and food processing. in this study, we investigated the preservability of Electrolyzed Water produced in a two-cell batch-type apparatus. It was found that Acidic Electrolyzed Water could be preserved for one year under shaded and sealed conditions. However, Acidic Electrolyzed Water became inert after three days when exposed to light, although pH remained stable for one year. It was found out that the quality of Alkaline Electrolyzed Water changes easily regardless of preservation conditions.
Article
Electrolytically generated chlorine was injected into citrus microirrigation systems. Propagules of Phytophthora nicotianae var. parasitica, P. citrophthora, Fusarium spp., algae, and slime-forming bacteria were killed. Nematodes were found to resist free-chlorine levels in water of up to 50 μg ml -1 . Microemitters delivering chlorinated water were less frequently blocked by bacterial and/or bacterial slime than those delivering unchlorinated water. Soil and root populations of Phytophthora and nematodes under citrus trees in the field were unaffected by chlorinated water. No chlorine-induced phytotoxicity was observed on field-grown plants(.)
Article
水道水を電気分解処理して得られたアルカリ性水の炊飯水としての有効性について検討を行い,以下の結果を得た.(1) 白米と浸漬水の総体積変化は,アルカリ水,原水(水道水),酸性水の順に大きくなった.任意のpHに調整された試験水を用いた実験より,白米の膨潤度はpHの影響を受けていることが確認された.(2) 画像処理装置により炊飯米形状を二次元的に計測し,面積はアルカリ性水,酸性水,原水の順に大きく,アルカリ性水のものは原水のものよりも約4.5%の差がみられた.(3) 三粒法により各米飯のテクスチャーを測定したが,粘りと硬さの比がアルカリ性水,酸性水,原水の順に大きな値をとった.アルカリ性水により処理された炊飯米のテクスチャーが高い原因として,炊飯米表面の糊化した澱粉量が多いことによるものであることが考えられた.洗米において白米からの澱粉の溶出量は,アルカリ性水処理によるものが最も高く,炊飯米においても同様であった.この原因として,洗米では高いpHや界面活性的な働きが白米表面物質の遊離を促進するため,また炊飯米では高いミネラル濃度が澱粉細胞の細胞壁に沿って存在するタンパク質の可溶性を促進するためと推察された.
Article
Electrolyzed water (EW) has attracted much recent attention as a high-performance, new technology for potential use in the food industry. However, this is the first review which examines the potential of the an-timicrobial effect of electrolyzed water solutions in many different food models such as vegetable, fruits, meat, poultry, fish, and other products. Production, theoretical of the chemical reactions in the production of EW, theories of disinfectant effect of EW and advantage of using EW would be reviewed. The purpose of this review is to introduce simple information about the use of this new technology in the field of food disinfection, for both readers and food industry. Zusammenfassung Elektrolysiertes Wasser (EW) gerät als potenzielle Technologie für die Le-bensmittelindustrie immer mehr in den Blickpunkt. Die vorliegende Arbeit gibt einen Überblick über ihre Einsatzmöglichkeiten. Keywords: Antimicrobial effect, electrolyzed water (EW), acidic electro-lyzed water [EW (+)], cathodic electrolyzed water [EW (–)], Sanitation / elektrolysiertes Wasser, antimikrobieller Effekt, Hygiene
Article
The fungicidal effectiveness of electrolyzed oxidizing (EO) water on peach [Prunus persica (L.) Batsch.] fruit was studied. Fruit were inoculated with a spore suspension of 5 x 105 conidia/mL of Monilinia fructicola [(G. Wint.) Honey] applied as a drop on wounded and nonwounded fruits, or by a uniform spray-mist on nonwounded fruits. Fruit were immersed in tap water at 26°C for 5 or 10 minutes (control), or treated with EO water varying in oxidation-reduction potential (ORP), pH, and free available chlorine (FAC). Following treatment, fruit were held at 20°C and 95% relative humidity for ≥10 days to simulate retail conditions. Disease incidence was determined as the percentage of fruits showing symptoms of the disease, while severity was expressed as lesion diameter. EO water did not control brown rot in wound-inoculated fruits, but reduced disease incidence and severity in nonwound-inoculated peach. Symptoms of brown rot were further delayed in fruit inoculated by a uniform-spray mist compared with the nonwounded-drop-inoculated peaches. Fruit treated with EO water held for 8 days at 2°C, 50% RH, did not develop brown rot, until they were transferred to 20°C, 95% RH. The lowest disease incidence and severity occurred in fruit immersed in EO water for up to 5 minutes. EO water having pH 4.0, ORP 1,100 mV, FAC 290 mg·L-1 delayed the onset of brown rot to 7 days, i.e., about the period peach stays in the market from a packing house to consumer. No chlorine-induced phytotoxicity was observed on the treated fruit. This study revealed that EO water is an effective surface sanitizer, but only delayed disease development.
Article
Hydrated pollen of Nicotiana tabacum L. (var. xanthi nc) was exposed to different concentrations of several volatile organic compounds. The germination rate of the pollen was determined by applying a modified test procedure originally developed by Kappler and Kristen (1990). A stimulation of pollen germination resulting through a rise in pCO2 was avoided by using a short exposure period. In the series of chlorinated ethanes, the ED50 (and ED25) values decrease with increasing number of chlorine atoms, which are correlated to a rise of the octanol-water partition coefficient. For the chlorinated ethenes a similar effect is probable, but less obvious. The toxicity of compounds with the same number of chlorine atoms is higher for ethane derivatives than for derivatives of ethene. The ED50 and ED25 values are compared with threshold values of physiological effects obtained after the application of 1,1,1-trichloroethane for 24 h to tobacco leaves. We presume that chlorinated hydrocarbons may cause stress even at lower concentrations than those suggested by the pollen test. Therefore the listed ED values (Table 1) should be considered as maximum tolerable values regarding phytotoxic effects in experimental investigations. For the important solvent 1,1,1-trichloroethane the ED25 value of phytotoxicity is lower than 4 mg/L; according to literature the concentration supposedly having no effect on man is 1.9 - 5.2 mg/L.
Article
The properties of tofu prepared with weakly electrolyzed waters (anode and cathode waters) obtained by electrolysis of tap water were investigated. The use of cathode water increased the protein content of the tofu. The texture of tofu prepared with cathode and anode waters was softer than that of tofu prepared with tap water. No significant difference in the free sugar content was seen between the tofu prepared with electrolyzed and non-electrolyzed waters. However, tofu prepared with cathode water was evaluated as sweeter than that prepared with tap water in a sensory test. The content of total carbonyl compounds, which is related to the substantial taste of tofu, was higher in the tofu prepared with cathode and anode waters than in that prepared with tap water. These results show that the eating quality of tofu can be modified by using electrolyzed water (especially cathode water) for its preparation.
Article
The effect of weakly electrolyzed water (anode water and cathode water) on the properties of Japanese wheat noodles was examined. Instrumental measurements and sensory tests of the cooked noodles revealed that noodles made by kneading wheat flour with anode water were harder and springier than those made by kneading wheat flour with tap water. This suggests that anode water provides a favorable texture to the cooked noodles. Anode water promoted the dissolution of gliadin and glutenin subunits which participate in the formation of gluten-matrix, so that the texture of cooked noodles was improved by kneading the wheat flour with this water. When noodles were cooked in either anode water or cathode water, they showed less springiness compared with those cooked in tap water. The use of either anode or cathode water for cooking changed the gelatinization condition of starch, which affects the texture of the cooked noodles.
Article
The use of electrolyzed water for washing and sanitizing eggshells and an egg washer was evaluated for its effectiveness at a Grade & Packing Center adjacent to a poultry farm for a period of nine months. The test results indicate improvement in sanitation control. Dissolving yolks of broken eggs with electrolyzed alkaline water followed by sanitizing with electrolyzed acidic water produced favorable effects. Also, the use of electrolyzed water has an advantage in that it simplifies the conventional washing and sanitizing process and motivates operators to employ the process more frequently. This sense developed in operators may be a significant factor in the improvement of sanitation control.
Article
The hide of cattle is known to be a source for the microbial contamination of beef, with microorganisms transferred onto the carcass from the hide, during the slaughter and dressing processes. To assess the potential risk of carcass contamination from food-borne bacterial pathogens on cattle hides, a study was carried out involving 90 beef cattle in the South-West of England to determine the prevalence of these microorganisms. A one-pass swab technique was carried out to sample a measured area on the rump, flank and brisket of each animal. These swabs were processed in the laboratory to determine the prevalence of E. coli O157, Salmonella spp., and Campylobacter spp. on these hide areas. The most contaminated area was the brisket with one in five animals testing positive for E. coli O157 (22.2% prevalence on average) and approximately one in 10 animals testing positive for Salmonella spp. (10.0% prevalence on average). The least contaminated area on the cattle hides was the rump area (3.3% prevalence for E. coli O157, 2.2% prevalence for Salmonella spp.). Campylobacter spp. was not isolated from any samples taken from the 90 cattle studied. The results of this study indicate that the brisket area on the hide of cattle most frequently carries food-borne pathogens and is therefore most likely to lead to cross-contamination of beef during the de-hiding process.
Article
For reducing bacterial contamination, electrolyzed oxidizing water (EO water) has been used to reduce microbial population on seafood and platform of fish retailer. The specimens of tilapia were inoculated with Escherichia coli and Vibrio parahaemolyticus, and then soaked into EO water for up to 10min. EO water achieved additional 0.7logCFU/cm2 reduction than tap water on E. coli after 1min treatment and additional treatment time did not achieved additional reduction. EO water treatment also reduced V. parahaemolyticus, by 1.5logCFU/cm2 after 5min treatment and achieved 2.6logCFU/cm2 reduction after 10min. The pathogenic bacteria were not detected in EO water after soaking treatment. In addition, EO water could effectively disinfect the platform of fish retailer in traditional markets and fish markets.
Article
Chlorination presents one of the few chemical options available to help manage postharvest decay. Electrolyzed oxidizing (EO) water, containing free chlorine, is the product of a new concept developed by scientists in Japan. The effectiveness of pear (Pyrus communis L.) immersion in EO water on the control of Bot. rot on European pear, cv. La-France, was investigated. Four independent experiments were carried out. A wound was found necessary for infection. Wounded fruit were inoculated with 20 μl spore suspension of 5×105 conidia/ml of Botryosphaeria berengeriana, incubated for 4 h, immersed in EO water, and held at 20 °C, ⩾90% relative humidity (simulated retail conditions) for ripening and disease development. No chlorine-induced phytotoxicity was observed on the treated fruit. EO water suppressed the incidence and disease severity. The minimum incidence and severity were recorded for a 10-min immersion period. This study revealed that EO water is an effective surface sanitizer.
Article
Acidic electrolyzed oxidizing (EO) water quickly kills a variety of fungi and shows promise as a broad-spectrum contact fungicide for control of foliar diseases of greenhouse-grown ornamentals. One requirement for use in the greenhouse is that EO water will not cause excessive phytotoxic symptoms on a wide variety of species. In one experiment, two applications of EO water did not damage 15 species of bedding plants. In a second experiment, EO water applied as a foliar spray three times per week for 4–7 weeks did not produce any visible phytoxicity on seven of the 12 species tested. Small, white spots were observed on flowers of geranium (Pelargonium x hortorum), impatiens (Impatiens walleriana), and vinca (Catharanthus roseus). Slight necrosis was observed on some leaf edges of petunia (Petunia x hybrida), and snapdragon (Antirrhinum majus). EO water generated from magnesium chloride produced more phytotoxicity than EO water generated by potassium chloride or sodium chloride. Phytotoxicity ratings of greater than 3 (0–10 scale) were not observed on any of the species tested. EO water caused slight damage to some plant species but, in general, appears to be safe to use as a foliar spray on a wide variety of bedding plants grown under greenhouse conditions.
Article
Acidic electrolyzed water (acidic EW), which is prepared by the electrolysis of an aqueous NaCl solution, has recently become of great importance for disinfection in a variety of fields, including medicine, the food industry and agriculture. In a previous paper we showed that: 1) acidic EW is a mixture of hypocholorite ion, hypochlorous acid and chlorine, depending upon the pH; 2) hypochlorous acid is primarily responsible for disinfection in the case of Escherichia coli K12 and Bacillus subtilis PCI219, both in clean culture media. In practice, however, the use of acidic EW is in many cases severely hampered due to the presence of a variety of non-selective reducing agents. In view of the salient nature of acidic EW, it is therefore strongly urged to establish an optimum way to use acidic EW in a variety of systems. The present paper is the first report on our attempt along this line in order to characterize the nature of the chemical changes that the bactericidal activity of the acidic EW deteriorates in the presence of organic materials, which include amino acids and proteins.
Article
Cut lettuce dip-inoculated with Escherichia coli O157:H7 and Salmonella was treated with alkaline electrolyzed water (AlEW) at 20°C for 5min, and subsequently washed with acidic electrolyzed water (AcEW) at 20°C for 5min. Pre-treatment with AlEW resulted in an approximate 1.8log10cfu/g reduction of microbial populations, which was significantly (p⩽0.05) greater than microbial reductions resulting from other pre-treatment solutions, including distilled water and AcEW. Repeated AcEW treatment did not show a significant bacterial reduction. Mildly heated (50°C) sanitizers were compared with normal (20°C) or chilled (4°C) sanitizers for their bactericidal effect. Mildly heated AcEW and chlorinated water (200ppm free available chlorine) with a treatment period of 1 or 5min produced equal reductions of pathogenic bacteria of 3log10 and 4log10cfu/g, respectively. The procedure of treating with mildly heated AlEW for 5min, and subsequent washing with chilled (4°C) AcEW for period of 1 or 5min resulted in 3–4log10cfu/g reductions of both the pathogenic bacterial counts on lettuce. Extending the mild heat pre-treatment time increased the bactericidal effect more than that observed from the subsequent washing time with chilled AcEW. The appearance of the mildly heated lettuce was not deteriorated after the treatment. In this study, we have illustrated the efficacious application of AlEW as a pre-wash agent, and the effective combined use of AlEW and AcEW.
Article
An acidic solution (pH 2.5∼2.6) with a high oxidation-reduction potential (ORP; about +1,170 mV) and an alkaline solution (pH 11.5∼11.7) with a low ORP (about −880mV) that resulted from electrolysis of 20 mM NaCl (dissolved in a pure water) were tested for their effect on the growth of Streptomyces spp. When spores (∼2×107) were exposed to the electrolyzed solutions (2 ml) for 1 minute, colony formation was totally inhibited by the acidic solution, but little by the alkaline solution although extending the exposure (10 minutes) resulted in a marked inhibition. The 1 minute exposure to their mixture (1:1, v/v) showed a strong inhibition (but weaker than that of the acidic solution). When the unexposed spores were streaked and incubated on ISP No. 4 (inorganic salts - starch medium) agar plate containing a cross density gradient of the acidic and alkaline solutions, a biased growth inhibition toward the acidic solution side was observed although the pH range of the acidic solution end of the plate was around 6.2. It seemed thus unlikely that low pH value contributed to the antimicrobial activity of the acidic solution. It was notable that S. griseus SS-1198 formed a unique morphology on the cross gradient plate.In addition, clear growth inhibition by the acidic solution was observed without direct contact with spores, probably because of chlorine gas release. Acidic solutions (pH 2.6∼2.7) resulting from the electrolysis of 20 mM of Na2SO4 show no significant antimicrobial activity when tested by the cross gradient plate method. It thus seemed likely that chlorine played a key role for the antimicrobial activity of the acidic electrolyzed NaCl solution.
Article
This study investigates the resistance of Listeria monocytogenes biofilms on stainless steel surfaces to electrolyzed oxidizing (EO) water. A direct agar overlay method was used to estimate the attached bacteria on stainless steel coupons after an EO water treatment. A scraping method was also used to quantify the adherent cell populations after the EO water treatment. The stainless steel surface allowed 10 to 15% of the surface area to be covered by Listeria biofilm when the inoculated stainless steel coupon was incubated in 10% tryptic soy broth (TSB) at 23C for 48 h. When the stainless steel coupons containing adherent cells were treated with EO water (56 mg/L of residual chlorine) for 10, 30, 60, 180, and 300 s, adherent cell populations (10.3 log10 CFU/coupon) were reduced with increasing treatment time. Although the direct agar overlay methods do not quantify survival of single bacteria, only one to five cell clumps per coupon survived after 300 s of the EO water treatment. Using the scraping method, the adherent cell population on the stainless steel coupons was reduced by about 9 log cycles after 300 s of EO water treatment.