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Neutral Electrolyzed Water –
an introduction
Neutral
Electrolyzed Water (NEW©) consist primarily of
chlorine (as HOCl and OCl- depending on pH), as well as other
chlorine ions that are short-lived when presented with an
oxidant-demanding substance; they react rapidly and are no longer
detectable in the water, leaving the chlorine component as a measurable
residual.
Neutral
Electrolyzed Water used in water treatment
The
use of chlorine gas to disinfect water has prevented disease and saved
millions of lives over the past century. Chlorination is regarded
as a reliable, cost-effective method for disinfecting water for drinking
purposes. It is used on small, remote plants and on large-scale
sophisticated drinking water treatment plants. However in remote areas
the application of chlorine presents problems where difficulties such as the
following, may exist.
·
Distance from the place of chlorine manufacture
·
Transport and delivery schedules are unreliable or non-existent;
·
Lack of sufficient expertise on the proper dosing of chlorine
(especially of gaseous chlorine);
·
The quality of chlorine gas obtained causes problems at the
point of dosing.
To
read more, please download The
use of electrochemical solutions in water treatment
Neutral Electrolyzed Water
for cooling tower treatment.
Enhanced
disinfection and minimal impact on scaling and corrosion are among the
promising results of using NEW©instead of oxidizing biocides
such as chlorine or bromine for cooling tower maintenance.
Results
show:
1. aerobic bacteria counts
consistently less than 1,000 milliliters in the cooling tower, a result
rarely achieved using chlorine alone or chlorine with other biocides
2. ease in maintaining free
available chlorine (FAC) concentrations at 0.2-0.3 milligrams per liter
(mg/L) using a standard ORP controller; and
3. removal of biofilms from
small areas of cooling surfaces where they had accumulated in the
previous maintenance program, and a consequent reduction or complete
elimination of microbiologically induced corrosion.
The
benefits of NEW© observed and general
application for cooling tower maintenance include:
a) aggressive disinfection -
elimination of biofilms, inactivation of pathogenic microorganisms
including Legionella species, and nil or low aerobic bacteria counts, all
without additional biocides
b) safe operations - because
only salt, water and power are used to generate the nonhazardous,
mixed-oxidant solution, liability exposure and associated management
costs are reduced, staff and community safety are improved and costs for
safe transportation, handling and storage of chlorine gas or hypochlorite
are eliminated
c) low maintenance - automated
systems require only minimal operator attention
Cooling
tower maintenance can include the following:
a) controlling deposition on
cooling surfaces (CaCO3, CaSO4 and SiO2) deposits
b) providing corrosion
protection for copper, copper/nickel tubing, admiralty (copper alloy) and
carbon and stainless steels
c) controlling microbiological
growth including biofilms on cooling surfaces and bacterial counts in the
cooling tower basin water
d) controlling airborne
impurities including contaminants and particulates washed out of the air
and other contaminants that enter external to the water source.
Chlorine
is currently the preferred disinfectant because of relatively low cost,
ease of use and control and a disinfection residual can be maintained.
Scaling
often is controlled by lowering the pH to less than 7.5 using H2SO4.
Lowering the pH also improves the biocidal effectiveness of chlorine by
increasing the fraction of the chlorine present as Hypochlorous Acid
(HOCl), which is the chlorine species most effective as a biocide.
It is therefore that NEW© is so successfully used, as
it’s main active substance is HOCL.
For more details download NEW in
cooling towers
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Various abstracts of
published articles about electrolyzed water
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Inactivation
of Escherichia coli O157:H7, Salmonella enteritidis and Listeria
monocytogenes on the surface of tomatoes by neutral electrolyzed
water
M.A. Deza, M. Araujo and M.J. Garrido
Institute of Food Research and Analysis, University of Santiago de Compostela, Santiago de Compostela, Spain
ABSTRACT
Aims: To determine the efficacy
of neutral electrolyzed water (NEW©) in killing Escherichia
coli OI57:H7, Salmonella enteritidis and Listeria
monocytogenes, as well as non-pathogenic E- coli, on the
surface of tomatoes, and to evaluate the effect of rinsing with NEW© on the organoleptic characteristics of
the tomatoes.
Methods
and Results:
The bactericidal activity of NEW©, containing 444 or 89 mg1-1
of active chlorine, was evaluated over pure cultures (8.5Iog CFU mI-1)
of the above-mentioned strains. All of them were reduced by more than 6
log CFU ml-1 within 5 min of exposure to NEW©. Fresh tomatoes were
surface-inoculated with the same strains, and rinsed in NEW© (89 mg1-1 of
active chlorine) or in deionized sterile water (control), for 30 or 60 s.
In the NEW© treatments, independent of the strain
and of the treatment time, an initial surface population of about 5 log
CFU sq.cm-1 was reduced to 5log CFU sq.cm-1, and no
cells were detected in the washing solution by plating procedure. A
sensory evaluation was conducted to ascertain possible alterations in
organoleptic qualities, yielding no significant differences with regard
to untreated tomatoes.
Significance
and Impact of the Study: Rinsing in NEW© reveals as an effective method to
control the presence of E. coli O157:H7, S. enteritidis and
L. monocytogenes on the surface of fresh tomatoes, without
affecting their organoleptic characteristics. This indicates its
potential application for the decontamination of fresh produce surfaces.
Keywords:
ANK-Anolyte, disinfectant, E.
coli O 157 :H7 , L. monocytogenes, neutral electroly'zed
water, organoleptic quality, rinsing fresh tomatoes, S. enteritidis.
Inactivation of
Cryptosporidium parvum oocysts and Clostridium perfringens spores by a
mixed-oxidant disinfectant and by free chlorine.
Venczel
LV, Arrowood
M, Hurd
M, Sobsey
MD.
University of North Carolina, Chapel Hill 27599, USA.
Cryptosporidium parvum oocysts and Clostridium perfringens spores are
very resistant to chlorine and other drinking-water disinfectants. Clostridium
perfringens spores have been suggested as a surrogate indicator of
disinfectant activity against Cryptosporidium parvum and other hardy
pathogens in water. In this study, an alternative disinfectant system
consisting of an electrochemically produced mixed-oxidant mixed-oxidant
solution was evaluated for inactivation of both Cryptosporidium parvum
oocysts and Clostridium perfringens spores. The disinfection efficacy of
the mixed-oxidant solution was compared to that of free chlorine on the
basis of equal weight per volume concentrations of total oxidants. Batch
inactivation experiments were done on purified oocysts and spores in
buffered, oxidant demand-free water at pH 7 an 25 degrees C by using a
disinfectant dose of 5 mg/liter and contact times of up to 24 h. The
mixed-oxidant solution was considerably more effective than free chlorine
in activating both microorganisms. A 5-mg/liter dose of mixed oxidants
produced a > 3-log10-unit (> 99.9%) inactivation of Cryptosporidium
parvum oocysts and Clostridium perfringens spores in 4 h. Free chlorine
produce no measurable inactivation of Cryptosporidium parvum oocysts by 4
or 24 h, although Clostridium perfringens spores were inactivated by 1.4
log10 units after 4 h. The on-site generation of mixed oxidants may be a
practical and cost-effective system of drinking water disinfection
protecting against even the most resistant pathogens, including
Cryptosporidium oocysts.
To
read the full article, please download Inactivation
of crypto
Activity of Electrolyzed
Oxidizing Water Against Penicilium expansum in Suspension and on Wounded
Apples
D.O. Okull and L.F. Laborde
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.
Keywords:
Penicillium expansum, electrolyzed oxidizing water, apples, patulin
To
read the full article, please download EO_Water_Apples.pdf
Effectiveness of Electrolyzed
Water Irrigation in a burn-wound infection model.
Hajime
Nakae, MD, PhD and Hideo Inaba, MD, PhD
Journal
of Trauma injury, infection and critical care
To
read the research, please download burn-wound
infection.pdf
______________________________________________________________________________________
Antioxidant effect of Reduced
Water (Alkaline Water) produced by the Electrolyses of Sodium chloride
solutions.
K.
Hanaoko
Journal
of Applied Electrochemistry
To
read article, please download Antioxidant
properties
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Bactericidal Activity of
Electrolyzed Acid Water from solution containing sodium chloride at low
concentration in comparison with that at high concentration.
Hiromasu
Kiura, Kouichi Sano, Sinitchi Morimatsu, Takashi Nakano, Chizuko Morita,
Masaki Yamaguchi, Tokoyoki Maedi, Yoji Katsuoka
Journal
of Microbiological Methods
To
read article, please download Bactericidal
Activity
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Enhanced disinfection
efficiency of mechanically mixed oxidants with free chlorine.
Son
H, Cho
M, Kim
J, Oh
B, Chung
H, Yoon
J.
School of Chemical Engineering, College of Engineering, Seoul National University, San 56-1, Sillim-dong,
Gwanak-gu, Seoul 151-742, Republic of Korea.
To the best of our knowledge, this study is the first investigation to be
performed into the potential benefits of mechanically mixed disinfectants
in controlling bacterial inactivation. The purpose of this study was to
evaluate the disinfection efficiency of mechanically mixed oxidants with
identical oxidant concentrations, which were made by adding small amounts
of subsidiary oxidants, namely ozone (O3), chlorine dioxide (ClO2),
hydrogen peroxide (H2O2) and chlorite (ClO2(-)), to free available
chlorine (Cl2), using Bacillus subtilis spores as the indicator
microorganisms. The mechanically mixed oxidants containing Cl2/O3,
Cl2/ClO2 and Cl2/ClO2(-) showed enhanced efficiencies (of up to 52%) in
comparison with Cl2 alone, whereas no significant difference was observed
between the mixed oxidant, Cl2/H2O2, and Cl2 alone. This enhanced
disinfection efficiency can be explained by the synergistic effect of the
mixed oxidant itself and the effect of intermediates such as
ClO2(-)/ClO2, which are generated from the reaction between an excess of
Cl2 and a small amount of O3/ClO2(-). Overall, this study suggests that
mechanically mixed oxidants incorporating excess chlorine can constitute
a new and moderately efficient method of disinfection.
Efficacy of electrolyzed water in the prevention and
removal of fecal material attachment and its microbicidal effectiveness
during simulated industrial poultry processing.
Kim C, Hung YC,
Russell SM.
Department of Food Science and Technology, College of Agricultural and
Environmental Sciences, University of Georgia, Griffin, Georgia 30223-1797, USA.
This study was undertaken to investigate the efficacy of alkaline and
acidic electrolyzed (EO) water in preventing and removing fecal
contaminants and killing Campylobacter jejuni on poultry carcasses under
simulated industrial processing conditions. New York dressed and defeathered chicken
carcasses spot-inoculated with cecal material or C. jejuni were subjected
to spraying treatment with alkaline EO or 10% trisodium phosphate (TSP) water or combinations of
spraying and immersion treatments with acidic EO and chlorinated water,
respectively. Prespraying chicken carcasses with alkaline EO water
significantly lowered cecal material attachment scores (3.77) than tap
water (4.07) and 10% TSP (4.08) upon treatment of the dorsal area.
Combinations of pre- and postspraying were significantly more effective
than postspraying only, especially when using alkaline EO water in
removing fecal materials on the surface of chicken carcasses. Although
treatment by immersion only in EO and chlorinated water significantly
reduced the initial population (4.92 log10 cfu/g) of C. jejuni by 2.33
and 2.05 log10 cfu/g, respectively, combinations of spraying and
immersion treatment did not improve the bactericidal effect of
sanitizers. The results indicated that alkaline EO water might provide an
alternative to TSP in preventing attachment and removal of feces
on the surface of chicken carcasses. The results also suggested that
chicken carcasses containing pathogenic microorganisms may contribute to
the cross-contamination of whole batches of chickens during processing in
the chiller tank and afterward.
Effects of electrolyzed oxidizing water on reducing
Listeria monocytogenes contamination on seafood processing surfaces.
Liu C, Duan J, Su YC.
College of Food Science and Technology, Shanghai Fisheries University, 334 Jungong Road, Shanghai 200-090, P.R. China.
The effects of electrolyzed oxidizing (EO) water on reducing Listeria
monocytogenes contamination on seafood processing surfaces were studied.
Chips (5 x 5 cm(2)) of stainless steel sheet (SS), ceramic tile (CT), and
floor tile (FT) with and without crabmeat residue on the surface were
inoculated with L. monocytogenes and soaked in tap or EO water for 5 min.
Viable cells of L. monocytogenes were detected on all chip surfaces with
or without crabmeat residue after being held at room temperature for 1 h.
Soaking contaminated chips in tap water resulted in small-degree
reductions of the organism (0.40-0.66 log cfu/chip on clean surfaces and
0.78-1.33 log cfu/chip on dirty surfaces). Treatments of EO water
significantly (p<0.05) reduced L. monocytogenes on clean surfaces
(3.73 log on SS, 4.24 log on CT, and 5.12 log on FT). Presence of
crabmeat residue on chip surfaces reduced the effectiveness of EO water
on inactivating Listeria cells. However, treatments of EO water also
resulted in significant reductions of L. monocytogenes on dirty surfaces
(2.33 log on SS and CT and 1.52 log on FT) when compared with tap water
treatments. The antimicrobial activity of EO water was positively
correlated with its chlorine content. High oxidation-reduction potential
(ORP) of EO water also contributed significantly to its antimicrobial
activity against L. monocytogenes. EO water was more effective than
chlorine water on inactivating L. monocytogenes on surfaces and could be
used as a chlorine alternative for sanitation purpose. Application of EO
water following a thorough cleaning process could greatly reduce L.
monocytogenes contamination in seafood processing environments.
Efficacy of ozonated and electrolyzed oxidative
waters to decontaminate hides of cattle before slaughter.
Bosilevac JM,
Shackelford SD,
Brichta DM,
Koohmaraie M.
US Department of Agriculture, Agricultural Research Service, Roman L.
Hruska US Meat Animal Research Center, Clay Center, Nebraska 68933-0166,
USA. bosilevac@email.marc.usda.gov
The hides of cattle are the primary source of pathogens such as
Escherichia coli O157:H7 that contaminate preevisceration carcasses
during commercial beef processing. A number of interventions that reduce
hide contamination and subsequent carcass contamination are currently
being developed. The objective of this study was to determine the
efficacy of ozonated and electrolyzed oxidizing (EO) waters to
decontaminate beef hides and to compare these treatments with similar
washing in water without the active antimicrobial compounds. Cattle hides
draped over barrels were used as the model system. Ozonated water (2 ppm)
was applied at 4,800 kPa (700 lb in2) and 15 degrees C for 10 s. Alkaline
EO water and acidic EO water were sequentially applied at 60 degrees C
for 10 s at 4,800 and 1,700 kPa (250 lb in2), respectively. Treatment
using ozonated water reduced hide aerobic plate counts by 2.1 log CFU/100
cm2 and reduced Enterobacteriaceae counts by 3.4 log CFU/100 cm2. EO
water treatment reduced aerobic plate counts by 3.5 log CFU/100 cm2 and
reduced Enterobacteriaceae counts by 4.3 log CFU/100 cm2. Water controls
that matched the wash conditions of the ozonated and EO treatments
reduced aerobic plate counts by only 0.5 and 1.0 log CFU/100 cm2,
respectively, and each reduced Enterobacteriaceae counts by 0.9 log
CFU/100 cm2. The prevalence of E. coli O157 on hides was reduced from 89
to 31% following treatment with ozonated water and from 82 to 35%
following EO water treatment. Control wash treatments had no significant
effect on the prevalence of E. coli O157:H7. These results demonstrate
that ozonated and EO waters can be used to decontaminate hides during
processing and may be viable treatments for significantly reducing
pathogen loads on beef hides, thereby reducing pathogens on beef
carcasses.
Enhancing the bactericidal effect of electrolyzed
water on Listeria monocytogenes biofilms formed on stainless steel.
Ayebah B,
Hung YC,
Frank JF.
Department of Food Science and Technology, University of Georgia, 1109
Experiment Street, Griffin, Georgia 30223, USA.
Biofilms are potential sources of contamination to food in processing
plants, because they frequently survive sanitizer treatments during
cleaning. The objective of this research was to investigate the combined
use of alkaline and acidic electrolyzed (EO) water in the inactivation of
Listeria monocytogenes biofilms on stainless steel surfaces. Biofilms
were grown on rectangular stainless steel (type 304, no. 4 finish)
coupons (2 by 5 cm) in a 1:10 dilution of tryptic soy
broth that contained a five-strain mixture of L. monocytogenes for 48 h
at 25 degrees C. The coupons with biofilms were then treated with acidic
EO water or alkaline EO water or with alkaline EO water followed by
acidic EO water produced at 14 and 20 A for 30, 60, and 120 s. Alkaline
EO water alone did not produce significant reductions in L. monocytogenes
biofilms when compared with the control. Treatment with acidic EO water
only for 30 to 120 s, on the other hand, reduced the viable bacterial
populations in the biofilms by 4.3 to 5.2 log CFU per coupon, whereas the
combined treatment of alkaline EO water followed by acidic EO water
produced an additional 0.3- to 1.2-log CFU per coupon reduction. The
population of L. monocytogenes reduced by treatments with acidic EO water
increased significantly with increasing time of exposure. However, no
significant differences occurred between treatments with EO water
produced at 14 and 20 A. Results suggest that alkaline and acidic EO
water can be used together to achieve a better inactivation of biofilms
than when applied individually.
Investigation of the presence of OH radicals in electrolyzed
NaCl solution by electron spin resonance spectroscopy.
Stan SD,
Woods JS,
Daeschel MA.
Department of Food Science and Technology, Oregon State University, 100 Wiegand Hall, Corvallis, Oregon 97331, USA.
In the anode side of a two-chamber electrolyzer, electrolysis of a NaCl
solution generates acidic electrolyzed oxidizing (EO) water, which
exhibits bactericidal effects against a large number of pathogens. This
study was undertaken to investigate whether OH radical species are
present in EO water or are formed when EO water reacts with iron ions.
Electron spin resonance spectroscopy (ESR) coupled with the spin
trapping technique was used for the detection of free radicals. Samples
of EO water were collected at 0.5, 1, 2, 3, and 5 min of electrolysis and
immediately mixed with the spin trapping agent
5,5-dimethyl-1-pyrroline-N-oxide (DMPO). The
5,5-dimethyl-2-hydroxypyrrolidine-N-oxyl (DMPO-OH) spin adduct,
characteristic of OH radicals, was not observed. Starting with 2-min
electrolysis, a seven-line spectrum characteristic of
5,5-dimethyl-2-pyrrolidone-N-oxyl (DMPOX) was formed. The reactions of EO
water with Fe3+ and Fe2+ in the presence of DMPO yielded the spin adduct
DMPO-OH. However, the addition of OH radical scavengers (ethanol and
methanol) did not generate the characteristic DMPO-alkyl spin adducts.
This indicated that the DMPO-OH spectrum was due to a nucleophilic
addition of water to DMPO and not to trapping of OH radicals.
Efficacy of electrolyzed water in inactivating
Salmonella enteritidis and Listeria monocytogenes on shell eggs.
Park CM,
Hung YC,
Lin CS, Brackett RE.
Department of Food Science and Technology, University of Georgia, Griffin, Georgia 30223-1797, USA.
The efficacy of acidic electrolyzed (EO) water produced at three levels
of total available chlorine (16, 41, and 77 mg/ liter) and chlorinated
water with 45 and 200 mg/liter of residual chlorine was investigated for
inactivating Salmonella Enteritidis and Listeria monocytogenes on shell
eggs. An increasing reduction in Listeria population was observed with
increasing chlorine concentration from 16 to 77 mg/liter and treatment
time from 1 to 5 min, resulting in a maximal reduction of 3.70 log CFU
per shell egg compared with a deionized water wash for 5 min. There was
no significant difference in antibacterial activities against Salmonella
and Listeria at the same treatment time between 45 mg/liter of
chlorinated water and 14-A acidic EO water treatment (P > or = 0.05).
Chlorinated water (200 mg/liter) wash for 3 and 5 min was the most
effective treatment; it reduced mean populations of Listeria and
Salmonella on inoculated eggs by 4.89 and 3.83 log CFU/shell egg,
respectively. However, reductions (log CFU/shell egg) of Listeria (4.39)
and Salmonella (3.66) by 1-min alkaline EO water treatment followed by
another 1 min of 14-A acidic EO water (41 mg/liter chlorine) treatment
had a similar reduction to the 1-min 200 mg/liter chlorinated water
treatment for Listeria (4.01) and Salmonella (3.81). This study
demonstrated that a combination of alkaline and acidic EO water wash is
equivalent to 200 mg/liter of chlorinated water wash for reducing
populations of Salmonella Enteritidis and L. monocytogenes on shell eggs.
Efficacy of electrolyzed oxidizing water for the
microbial safety and quality of eggs.
Bialka KL,
Demirci A,
Knabel SJ,
Patterson PH,
Puri VM.
Department of Agricultural & Biological Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
During commercial processing, eggs are washed in an alkaline detergent
and then rinsed with chlorine to reduce dirt, debris, and microorganism
levels. The alkaline and acidic fractions of electrolyzed oxidizing (EO)
water have the ability to fit into the 2-step commercial egg washing
process easily if proven to be effective. Therefore, the efficacy of EO
water to decontaminate Salmonella Enteritidis and Escherichia coli K12 on
artificially inoculated shell eggs was investigated. For the in vitro
study, eggs were soaked in alkaline EO water followed by soaking in
acidic EO water at various temperatures and times. Treated eggs showed a
reduction in population between > or = 0.6 to > or =2.6 log10 cfu/g
of shell for S. Enteritidis and > or =0.9 and > or =2.6 log10 for
E. coli K12. Log10 reductions of 1.7 and 2.0 for S. Enteritidis and E.
coli K12, respectively, were observed for typical commercial
detergent-sanitizer treatments, whereas log10 reductions of > or =2.1
and > or =2.3 for S. Enteritidis and E. coli K12, respectively, were
achieved using the EO water treatment. For the pilot-scale study, both
fractions of EO water were compared with the detergent-sanitizer
treatment using E. coli K12. Log10 reductions of > or = 2.98 and >
or = 2.91 were found using the EO water treatment and the
detergent-sanitizer treatment, respectively. The effects of 2 treatments
on egg quality were investigated. EO water and the detergent-sanitizer
treatments did not significantly affect albumen height or eggshell
strength; however, there were significant affects on cuticle presence.
These results indicate that EO water has the potential to be used as a
sanitizing agent for the egg washing process.
Efficacy of acidic electrolyzed water ice for
pathogen control on lettuce.
Koseki S,
Isobe S,
Itoh K.
Food Processing Laboratory, National Food Research Institute, 2-1-12 Kannondai, Tsukuba 305-8642, Japan. koseki@nfri.affrc.go.jp
Acidic electrolyzed water (AcEW) was used as frozen AcEW (AcEW-ice) for
inactivation of Listeria monocytogenes and Escherichia coli O157:H7 on
lettuce. AcEW-ice was prepared from AcEW with 20, 50, 100, and 200 ppm of
available chlorine by freezing at -40 degrees C and generated 30, 70,
150, and 240 ppm of chlorine gas (Cl2), respectively. The AcEW-ice was
placed into styrene-foam containers with lettuce samples at 20 degrees C
for 24 h. Although AcEW-ice generating 30 ppm Cl2 had no effect on L.
monocytogenes cell counts, AcEW-ice generating 70 to 240 ppm of Cl2
significantly (P < 0.05) reduced L. monocytogenes by ca. 1.5 log
CFU/g. E. coli O157:H7 cell counts were reduced by 1.0 log CFU/g with
AcEW-ice generating 30 ppm of Cl2. AcEW-ice generating 70 and 150 ppm of
Cl2 reduced E. coli O157:H7 by 2.0 log CFU/g. Further significant
reduction of E. coli O157:H7 (2.5 log CFU/g) was demonstrated by treatment
with AcEW-ice generating 240 ppm of Cl2. However, treatment with AcEW-ice
generating 240 ppm of Cl2 resulted in a physiological disorder resembling
leaf burn. AcEW-ice that generated less than 150 ppm of Cl2 had no effect
on the surface color of the lettuce. AcEW-ice, regardless of the
concentration of the emission of Cl2, had no effect on the ascorbic acid
content in the lettuce. The weight ratio of lettuce to AcEW-ice required
was determined to be over 1:10. The bactericidal effect of
AcEW-ice appeared within the first 2 h. The use of AcEW-ice provides
simultaneously for low temperature storage and inactivation of bacteria.
The efficacy of function water (electrolyzed strong
acid solution) on open heart surgery; postoperative mediastinitis due to
methicillin-resistant Staphylococcus aureus]
[Article in Japanese]
Ichihara T,
Fujii G,
Eda T, Sasaki M,
Ueda Y.
Department of Cardiovascular Surgery, Tosei General Hospital, Seto, Japan.
Methicillin-resistant Staphylococcus aureus (MRSA) infection after cardiac
surgery has recently increased. We compared the anti-inflammatory effect
of an electrolyzed strong acid solution and a warm saline solution in
patients with open heart surgery. These solutions were used for
mediastinal irrigation before closing the sternum. Group A patients were
irrigated by a warm saline solution, and group B patients were irrigated
by an electrolyzed strong acid solution, administration of this water is
safe, feasible, and easy for the prevention of MRSA infection. Postoperative
infection was significantly decreased in the group B as compared in the
group A. An electrolyzed strong acid solution may be effective on
postoperative infection, particularly MRSA infection following open
heart surgery.
Effects of water source, dilution, storage, and
bacterial and fecal loads on the efficacy of electrolyzed oxidizing water
for the control of Escherichia coli O157:H7.
Stevenson SM,
Cook SR,
Bach SJ,
McAllister TA.
Agriculture and Agri-Food Canada Research Centre, Lethbridge, Alberta, Canada T1J 4B1.
To evaluate the potential of using electrolyzed oxidizing (EO) water for
controlling Escherichia coli O157:H7 in water for livestock, the effects
of water source, electrolyte concentration, dilution, storage conditions,
and bacterial or fecal load on the oxidative reduction potential (ORP)
and bactericidal activity of EO water were investigated. Anode and
combined (7:3 anode:cathode, vol/vol) EO waters reduced the pH and
increased the ORP of deionized water, whereas cathode EO water increased
pH and lowered ORP. Minimum concentrations (vol/vol) of anode and
combined EO waters required to kill 10(4) CFU/ml planktonic suspensions
of E. coli O157:H7 strain H4420 were 0.5 and 2.0%, respectively. Cathode
EO water did not inhibit H4420 at concentrations up to 16% (vol/vol).
Higher concentrations of anode or combined EO water were required to elevate
the ORP of irrigation or chlorinated tap water compared with that of
deionized water. Addition of feces to EO water products (0.5% anode or
2.0% combined, vol/vol) significantly reduced (P < 0.001) their ORP
values to < 700 mV in all water types. A relationship between ORP and
bactericidal activity of EO water was observed. The dilute EO waters
retained the capacity to eliminate a 10(4) CFU/ml inoculation of E. coli
O157:H7 H4420 for at least 70 h regardless of exposure to UV light or
storage temperature (4 versus 24 degrees C). At 95 h and beyond, UV
exposure reduced ORP, significantly more so (P < 0.05) in open than in
closed containers. Bactericidal activity of EO products (anode or
combined) was lost in samples in which ORP value had fallen to < or =
848 mV. When stored in the dark, the diluted EO waters retained an ORP of
> 848 mV and bactericidal efficacy for at least 125 h; with
refrigeration (4 degrees C), these conditions were retained for at least
180 h. Results suggest that EO water may be an effective means by which
to control E. coli O157:H7 in livestock water with low organic matter
content.
Efficacy of electrolyzed acid water in reprocessing
patient-used flexible upper endoscopes: Comparison with 2% alkaline
glutaraldehyde.
Lee JH, Rhee PL,
Kim JH, Kim JJ, Paik SW,
Rhee JC,
Song JH,
Yeom JS,
Lee NY.
Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-Dong.
Kangnam-Ku, Seoul 135-710, Korea.
BACKGROUND AND AIM: Two percent glutaraldehyde,
the most widely used liquid chemical germicide (LCG), may be hazardous to
patients and medical personnel. Alternatives to glutaraldehyde, such as
electrolyzed acid water (EAW), are being developed, but data from
well-controlled studies with patient-used endoscopes are rare. The
purpose of the present paper was to evaluate the high-level disinfection
capability of EAW and compare it with glutaraldehyde. METHODS: A random
sample of 125 endoscopes was collected immediately after upper endoscopic
examination. After careful manual cleaning, endoscopes were divided into
a glutaraldehyde and EAW group. After the disinfection procedure, samples
from working channel (S-1), insertion tube (S-2), umbilical cord (S-3),
and angulation knob (S-4) were taken and cultured. Another twenty
endoscopes were experimentally contaminated with hepatitis B virus (HBV)
and samples were collected after contamination (T-1), after manual
cleaning (T-2), and after final disinfection (T-3). Polymerase chain
reaction (PCR) for HBV-DNA was performed. RESULTS: In
the EAW group, culture-positive rates were 3.2% in S-1, 9.5% in S-2, 3.2%
in S-3, and 27.0% in the S-4 samples. There was no significant difference
between the EAW and glutaraldehyde groups for all sampling sites.
However, in both groups, disinfection of the angulation knobs (S-4) was
less efficient than the others. For the T-1 site, HBV-DNA was detected from all of
them, and in 95% (19/20) of T-2. However, HBV-DNA was not detected from T-3
samples. CONCLUSIONS: Electrolyzed acid water is as efficient as
glutaraldehyde in eliminating bacteria from patient-used endoscopes.
After disinfection procedures using both methods, HBV-DNA was not detected from any
endoscopes experimentally contaminated with HBV-positive mixed sera.
However, some bacteria may remain on the surface of the endoscopes.
Therefore, more careful precleaning of the endoscopes may help achieve
high-level disinfection in the clinical setting.
Efficacy of acidic electrolyzed water for microbial
decontamination of cucumbers and strawberries.
Koseki S,
Yoshida K,
Isobe S,
Itoh K.
Food Processing Laboratory, National Food Research Institute, 2-1-12 Kannondai, Tsukuba 305-8642, Japan. koseki@nfri.affrc.go.jp
An examination was made of the efficacy of acidic electrolyzed water
(AcEW, 30 ppm free available chlorine), ozonated water (5 ppm ozone), and
a sodium hypochlorite solution (NaOCl, 150 ppm free available chlorine)
for use as potential sanitizers of cucumbers and strawberries. AcEW and
NaOCl reduced the aerobic mesophiles naturally present on cucumbers
within 10 min by 1.4 and 1.2 log CFU per cucumber, respectively. The
reduction by ozonated water (0.7 log CFU per cucumber) was significantly
less than that of AcEW or NaOCl (P < or = 0.05). Cucumbers washed in
alkaline electrolyzed water for 5 min and then treated with AcEW for 5
min showed a reduction in aerobic mesophiles that was at least 2 log CFU per
cucumber greater than that of other treatments (P < or = 0.05). This
treatment was also effective in reducing levels of coliform bacteria and
fungi associated with cucumbers. All treatments offered greater microbial
reduction on the cucumber surface than in the cucumber homogenate.
Aerobic mesophiles associated with strawberries were reduced by less than
1 log CFU per strawberry after each treatment. Coliform bacteria and
fungi associated with strawberries were reduced by 1.0 to 1.5 log CFU per
strawberry after each treatment. Microbial reduction was approximately
0.5 log CFU per strawberry greater on the strawberry surface than in the
strawberry homogenate. However, neither treatment was able to completely
inactivate or remove the microorganisms from the surface of the cucumber
or strawberry.
The bactericidal effects of electrolyzed oxidizing
water on bacterial strains involved in hospital infections.
Vorobjeva NV,
Vorobjeva LI,
Khodjaev EY.
Department of Physiology of Microorganisms, Biology Faculty, Moscow State
University, Lenin Hills 1/12, Moscow 119992, Russia. nvvorobjeva@mail.ru
The study is designed to investigate bactericidal actions of electrolyzed
oxidizing water on hospital infections. Ten of the most common
opportunistic pathogens are used for this study. Cultures are inoculated
in 4.5 mL of electrolyzed oxidizing (EO) water or 4.5 mL of sterile
deionized water (control), and incubated for 0, 0.5, and 5 min at room
temperature. At the exposure time of 30 s the EO water completely
inactivates all of the bacterial strains, with the exception of
vegetative cells and spores of bacilli which need 5 min to be killed. The
results indicate that electrolyzed oxidizing water may be a useful
disinfectant for hospital infections, but its clinical application has
still to be evaluated.
Bactericidal effects of acidic electrolyzed water on
the dental unit waterline.
Kohno S,
Kawata T,
Kaku M, Fuita T,
Tsutsui K,
Ohtani J,
Tenjo K,
Motokawa M,
Tohma Y,
Shigekawa M,
Kamata H,
Tanne K.
Department of Orthodontics and Craniofacial Developmental Biology, Hiroshima University, Hiroshima 734-8553, Japan. acho@hiroshima-u.ac.jp
Many studies have been conducted in the United States regarding the microbial
contamination of dental unit waterline, but not in Japan. Recently, acidic
electrolyzed water has been used in the medical and dental fields. In
this study, we investigated the bactericidal effects of the temporary
inflow of acidic electrolyzed water on microbial contamination of the
dental unit waterline. First, in order to observe the daily bacterial
contamination of the dental unit waterline, water samples were collected
at the end of handpieces and three-way syringes before the inflow of
acidic electrolyzed water. They were cultured to detect viable bacteria.
Later, the inflow of acidic electrolyzed water was conducted through the
piping box of the dental unit. Before starting operation on next day,
water samples were collected and cultured, as described above. The mean
viable bacteria count was 910 -/+ 190 CFU/ml at the end of handpieces,
and 521 -/+ 116 CFU/ml at the end of three-way syringes before the inflow
of acidic electrolyzed water. However, bacteria were detected in only
small numbers at the end of handpieces and three-way syringes on the next
day. These results indicated that acidic electrolyzed water could be
applied as an appropriate measure against bacterial contamination of the
dental unit waterline.
Corrosion behavior of dental alloys in various types
of electrolyzed water.
Dong H, Nagamatsu Y,
Chen KK,
Tajima K,
Kakigawa H,
Shi S, Kozono Y.
Pedodontics Research Institute, Tongji University, 2, Lane 158, DaMuQiao
Rd., Ste. 402 Shanghai, 200032, PR China.
The corrosion behavior of dental alloys was examined in electrolyzed
strong acid water, weak acid water and neutral water using a 7-day
immersion test. The precious metal alloys, gold alloy. Au-Ag-Pd alloy and
silver alloy showed the greatest surface color change and dissolution of
constituents in the strong acid water and the smallest in the neutral
water. The release of Au from gold alloy was especially marked in the
strong acid water. Co-Cr alloy showed greater corrosion and tarnish
resistance in the strong acid water rather than in the weak acid water
and the neutral water. X-ray microanalysis revealed that the corrosion
products on the precious metal alloys were silver chloride crystals and
the thin brown products on Co-Cr alloy were cobalt and chromium oxides.
Ti was sound in all three types of electrolyzed water. The neutral water
appeared the least corrosive to metals among the three types showing
equivalent bactericidal activity.
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