Total Microbial Count

Wound debridement is considered essential in chronic wound management. Hypochlorous acid has been shown to be an effective agent in reducing wound bacterial counts in open wounds. Ultrasound-enabled wound debridement is an effective and efficient method of debridement. This study compared ultrasound irrigation with hypochlorous acid versus saline irrigation for wound debridement on pre- and postoperative wounds and determined regrowth of bacteria over 1 week period of time. Finally, the outcome of definitive wound closure of the clinically clean-appearing wounds was recorded. Methods: Seventeen consenting adult patients with chronic open wounds were randomly selected for study. The patients were randomly divided into the hypochlorous acid irrigation or saline irrigation group. All patients provided pre- and postoperative tissue samples for qualitative and quantitative bacteriology. For the time (7 days) between the debridement procedure and the definitive closure procedure, the wounds were dressed with a silver-impregnated dressing and a hydroconductive dressing. Results: Both types of irrigation in the ultrasonic system initially lowered the bacterial counts by 4 to 6 logs. However, by the time of definitive closure, the saline-irrigated wounds had bacterial counts back up to 105 whereas the hypochlorous acid–irrigated wounds remained at 102 or fewer. More than 80% of patients in the saline group had postoperative closure failure compared with 25% of patients in the hypochlorous acid group. Conclusions: Hypochlorous acid irrigation with ultrasound debridement reduced bacterial growth in chronic open wounds more efficiently than saline alone. Postoperative wound closure outcomes suggest a remarkable reduction in wound complications after wound debridement using hypochlorous acid irrigation with ultrasound versus saline alone.

Slightly acidic electrolyzed water (SAEW) spray has been considered as a novel approach for airborne bacteria reduction in animal housing. This study aimed to optimize the operating parameters of SAEW spray based on the size distribution of sprayed aerosols, the available chlorine travelling loss in sprayed aerosols, and the reduction efficiency of airborne culturable bacteria (CB). The optimized operating parameters were the nozzle orifice diameter and the spray pressure. The size distribution characteristics of sprayed SAEW aerosols under different operating parameters were quantified. The pH and available chlorine concentrations of the original SAEW solution and the SAEW aerosols collected at 0 m, 0.25 m, 0.50 m, 0.75 m, and 1.00 m from the spray nozzle head were analyzed. A bioaerosol nebulizing generator was used to simulate animal housing environment in an environmentally-controlled chamber. Six SAEW spray trials under different operating parameters were conducted at a spray dosage of 80 mL/m2 in the chamber. Airborne CB concentrations before and after spray were measured to investigate the reduction efficiency of airborne CB. Dv(50), the volume-based diameter below which 50% of the particle being present, increased with the nozzle orifice diameter and decreased with the spray pressure. The travelling loss of available chlorine in the sprayed SAEW aerosols was greatly dependent on Dv(50). SAEW spray with medium size sprayed aerosols (Dv(50) = 86.62 μm, 67.94 μm, and 54.53 μm) showed significantly higher airborne CB reduction efficiencies than large (Dv(50)=121.80 μm and 96.00 μm) or small size aerosols (Dv(50) = 42.57 μm). The spray operating parameters that provide medium size sprayed aerosols (Dv(50) ~ 60-90 μm) are recommended for SAEW spray in animal housing.
Keywords: animal housing, bioaerosol, available chlorine, size distribution, air quality, poultry and livestock
DOI: 10.3965/j.ijabe.20160904.2366

Citation: Zheng W C, Ni L, Hui X, Li B M, Zhang J F. Optimization of slightly acidic electrolyzed water spray for airborne culturable bacteria reduction in animal housing. Int J Agric & Biol Eng, 2016; 9(4): 185-191.

Three experiments were performed to enumerate the natural microflora on unwashed peaches, known as “field” peaches, and to determine the efficacy of using acidified electrolyzed water as a topical antimicrobial to remove or reduce the number of the natural microflora or inoculated Listeria innocua from to peach surfaces. During the first experiment, field peaches were divided into four treatment groups: no wash (NW), tap water wash (TW), acidified electrolyzed water wash (AEW), and chlorinated water wash (CL). Peaches were dipped into each of the treatment solutions at ambient temperature and immediately removed (approximately 5 seconds). Peaches were then rinsed in 100 mL of 0.1% peptone and rinsates were plated on aerobic plate count agar for enumeration. For the second experiment, exposure time to the treatment solutions and the temperature of the same treatment solutions were studied. Field peaches were again divided into NW, TW, AEW, and CL but treatments were applied using two exposure times of 5 seconds and 40 minutes at a temperature of 2°C (samples were given either a “0” or “40” in their labels to denote exposure time in minutes where 5 second exposures = 0 minutes e.g. TW-0, TW-40, AEW-0, etc.). Rinsing and plating was conducted as mentioned above. Experiment three investigated the efficacy of NW, TW, AEW, and Cl, in reducing numbers of Listeria innocua on peaches that were previously inoculated and held at 4°C for 24 hours. Inoculated peaches were dipped in treatment solutions for 5 second and 40 minute times at 2°C. Results showed that exposure time had a significant effect on bacterial reduction for both AEW and Cl treatments. Average aerobic counts from all NW peaches was 4.2 log10 CFU/g peach for natural microflora and 4.3 log10 CFU/g peach for samples inoculated with Listeria.

The combined effect of weakly acidic electrolyzed water (WAEW) ice-glazing and modified atmosphere packaging (MAP) treatment on the quality of pacific white shrimp (Litopenaeus vannamei) during frozen storage was investigated in terms of microbiological activity, TVBN, TMA and TBARS content, texture, color and volatile flavor analysis. As a result, significantly (p < 0.05) higher inhibitor effects on total aerobes and Staphylococcus aureus were observed in WAEW ice-glazed shrimp packaged in 40% CO2 + 10% O2 + 50% N2 or in 30% CO2 + 20% O2 + 50% N2 than the water- and WAEW ice-glazed batches. Additionally, chemical analysis results showed that WAEW ice-glazing combined with MAP was highly effective in maintaining lower TVBN, TMA and TBARS values in frozen shrimp, perhaps due to the synergistic effect of antibacterial and antioxidant abilities. On the other hand, the texture, L*, and a* results also confirmed that this combined treatment effectively retarded the degradation of the physical structure of shrimp muscle and showed a positive effect on the stability of color during frozen storage. However, the presence of WAEW ice-glaze showed a negative effect on the volatile flavor of thawed shrimp due to the volatile chlorine and chlorine dioxide, but no significant effect in the cooked samples. Overall, the application of WAEW ice-glazing combined with MAP on peeled frozen shrimp is advisable to achieve better quality maintenance and extend the shelf-life of refrigerated products.

Apart from these physical methods, the efficacy of chemical sanitizers, such as chlorine and chlorine-based sanitizers (Kim, Huang, Marshall, & Wei, 1999) and acidic electrolyzed water (AEW) (Mccarthy & Burkhardt, 2012;Ozer & Demirci, 2006a;Rahman, Khan, & Oh, 2016) have been also assessed for disinfection of raw fish during processing. Interestingly, AEW is broadly applied in Japan as a washing step for raw fish in sushi industry (Rahman et al., 2016), and advised as sanitizer in aquatic foods for shelf-life extension (Rasco & Ovissipour, 2015). Furthermore, the concept of biopreservation, which involves the addition of antagonistic, bacteriocin-producing lactic acid bacteria has been also introduced to control the growth of Listeria spp. on smoked salmon (Vescovo, Scolari, & Zacconi, 2006). …
… Moreover, low bacterial reduction might be explained by insufficiently short time (1 min, in this study) of treatment and that raw fish tissue is a difficult food matrix for decontamination, which strongly attach bacterial cells, compared to skin surface (Mahmoud et al., 2004). Hence, to overcome this drawback, combining effect of two or more discontamination methods in lower quantities could be applied (Rahman et al., 2016;Rasco & Ovissipour, 2015). …
… Likewise, Ozer and Demirci (2006a) reported higher inactivation of L. monocytogenes Scott A (1.12 log CFU/g) at 35 C compared to 22 C (0.4 log CFU/g). However, increased temperatures of AEW treatment were not recommended for application in seafood industry due to possible quality change of seafood (Rasco & Ovissipour, 2015)

This study evaluated the efficacy of individual treatments (thermosonication [TS+DW] and slightly acidic electrolyzed water [SAcEW]) and their combination on reducing Escherichia coli O157:H7, Listeria monocytogenes, and spoilage microorganisms (total bacterial counts [TBC], Enterobacteriaceae, Pseudomonas spp., and yeast and mold counts [YMC]) on fresh-cut kale. For comparison, the antimicrobial efficacies of sodium chlorite (SC; 100 mg/L) and sodium hypochlorite (SH; 100 mg/L) were also evaluated. Each 10 g sample of kale leaves was inoculated to contain approximately 6 log CFU/g of E. coli O157:H7 or L. monocytogenes. Each inoculated or uninoculated samples was then dip treated with deionized water (DW; control), TS+DW, and SAcEW at various treatment conditions (temperature, physicochemical properties, and time) to assess the efficacy of each individual treatment. The efficacy of TS+DW or SAcEW was enhanced at 40 °C for 3 min, with an acoustic energy density of 400 W/L for TS+DW and available chlorine concentration of 5 mg/L for SAcEW. At 40 °C for 3 min, combined treatment of thermosonication 400 W/L and SAcEW 5 mg/L (TS+SAcEW) was more effective in reducing microorganisms compared to the individual treatments (SAcEW, SC, SH, and TS+DW) and combined treatments (TS+SC and TS+SH), which significantly (P < 0.05) reduced E. coli O157:H7, L. monocytogenes, TBC, Enterobacteriaceae, Pseudomonas spp., and YMC by 3.32, 3.11, 3.97, 3.66, 3.62, and >3.24 log CFU/g, respectively. The results suggest that the combined treatment of TS+SAcEW has the potential as a decontamination process in fresh-cut industry.

Introduction: Spray-application of membraneless acidic electrolyzed water (MLAEW) is a novel technique for disinfection in livestock houses. This study investigated the loss of free chlorine (FC – the major germicidal component in MLAEW) over distance during spraying, as affected by air temperature and initial FC concentration. The anti-microbial effect of MLAEW on airborne bacteria from an aviary laying-hen house was examined.

Materials and methods: MLAEW was prepared at two FC concentrations: app. 15 and 60 mg L⁻¹, and sprayed at three air temperatures (18, 25, 32 °C). The original MLAEW solution and MLAEW aerosols collected at 0, 25, and 50 cm from the spray nozzle were analyzed for FC concentrations. Bacteria were immersed into these MLAEW samples and numerated for viable count after 0.5, 2 and 5-min treatments.

Results: MLAEW aerosols collected at 0 cm lost 11.7-13.2% FC, compared with the original MLAEW solution. This initial loss was affected neither by the initial FC concentration (P = 0.13) nor by air temperature (P = 0.57). The rate of FC loss during travelling was 0.79-0.87 % per cm of aerosol travel distance (% cm⁻¹) at 18 °C, 1.08-1.15 % cm⁻¹ at 25 °C, and 1.35-1.49% cm⁻¹ at 32 °C. This travelling loss was affected by air temperature (P = 0.02), but not by initial FC concentration (P = 0.38). Bacteria were completely inactivated at 0.5 min when treated with MLAEW samples with FC > 16.8 mg L⁻¹, in 2 min when FC > 13.8 mg L⁻¹, and in 5 min when FC > 7.2 mg L⁻¹.

Conclusion: Airborne bacteria from aviary hen house can be effectively inactivated by MLAEW with adequate FC concentration and contact time. During spraying, the anti-microbial efficacy of MLAEW aerosols decreased over distance due to FC loss which exacerbated at higher air temperatures.

Compared to conventional cage laying-hen houses, aviary hen houses generally have much higher concentrations of airborne dust and bacteria due to generation of bioaerosols by the hens’ access to and activities on the litter floor. Hence, reducing these airborne agents is important to safeguard the health of the animals and workers in such housing systems. Spraying slightly acidic electrolyzed water (SAEW) is a novel approach to reducing airborne culturable bacteria (CB) and particulate matter (PM) levels in hen houses. The objective of this study was to evaluate the efficacy of reducing airborne CB and PM in an experimental aviary chamber by periodic spraying of SAEW (Trt), as compared to no spraying (Ctrlns) or spraying of tap water (Ctrlw). The hens were provided 16 h light and 8 h dark (lights on at 6:00 h and off at 22:00 h) and were given access to the litter floor from 12:00 h to 22:00 h. The Trt regimen sprayed SAEW at 14:00 h for 15 min at a dosage of 80 mL m-2; the Ctrlns regimen had no spraying; and the Ctrlw regimen sprayed tap water following the same procedure as with Trt. Concentrations of airborne CB and PM in six aerodynamic size ranges (0.65-1.1, 1.1-2.1, 2.1-3.3, 3.3-4.7, 4.7-7.1, and >7.1 μm) were measured at 1.5 m above the floor in the center of the room during the periods of 13:45-14:00 h and 14:45-15:00 h. Compared to Ctrlns, spraying SAEW significantly reduced airborne CB (>2.1 μm) by up to 49% ±10% (p < 0.05), while Ctrlw did not show a reduction effect. No significant difference was found between Trt and Ctrlw in reducing airborne PM, although both reduced or tended to suppress PM >7.1 μm in size. The results show that spraying SAEW can inactivate airborne CB attached to PM. Thus, this is a promising technique for alleviating the adverse health impacts of bioaerosols in aviary laying-hen housing systems.

Reducing airborne microorganisms may potentially improve the environment in layer breeding houses. The effectiveness of slightly acidic electrolyzed water (SAEW; pH 5.29–6.30) in reducing airborne microorganisms was investigated in a commercial layer house in northern China. The building had a tunnel-ventilation system, with an evaporative cooling. The experimental area was divided into five zones along the length of the house, with zone 1 nearest to an evaporative cooling pad and zone 5 nearest to the fans. The air temperature, relative humidity, dust concentration, and microbial population were measured at the sampling points in the five zones during the study period. The SAEW was sprayed by workers in the whole house. A six-stage air microbial sampler was used to measure airborne microbial population. Results showed that the population of airborne bacteria and fungi were sharply reduced by 0.71 × 105 and 2.82 × 103 colony-forming units (CFU) m−3 after 30 min exposure to SAEW, respectively. Compared with the benzalkonium chloride (BC) solution and povidone-iodine (PVP-I) solution treatments, the population reductions of airborne fungi treated by SAEW were significantly (P < 0.05) more, even though the three disinfectants can decrease both the airborne bacteria and fungi significantly (P < 0.05) 30 min after spraying.

The work presented here aims to contribute with a sustainable alternative to chemicals for avoiding deterioration of harvested date palm fruits by evaluating the single or combined use of UV-C radiation and ozonated or electrolyzed water (EW). In this way, the effects of UV-C light (0; 2.37; 6.22; 8.29 and 12.14 kJ m−2) alone, and the combined effect of 6.22 kJ m−2 UV-C with neutral EW (NEW, pH 6.99, 870 mV ORP, 100 mg L−1 free chlorine), alkaline EW (AEW, pH 11.28, −880 mV ORP, 1.83 mg L−1 free chlorine) and ozonated (O3, 0.55 mg/L ozone) water on overall quality of Deglet Nour dates stored for 30 days at 20 °C were studied. Microbial growth, weight loss, firmness, pH, titratable acidity, moisture, water activity, sugars and phenolics content, antioxidant activity color and sensory quality were monitored. UV-C light, mainly at 6.22 kJ m−2, alone or combined with NEW, AEW and O3, kept the overall quality of dates during storage, Moreover, those treatments reduced the most mesophilic, coliforms, yeasts and molds counts. In summary, these combined emergent sanitizers could be useful for disinfection of fresh dates while keeping quality and prolonging shelf-life.

This study aimed to monitor the microbiological effect of cleaning near-patient sites
over a 48 hour period with a novel disinfectant, electrolysed water.

One acute care of the elderly ward in a district general hospital in Scotland.

Lockers, left and right cot-sides and overbed tables in 30 bed spaces were screened
for aerobic colony counts (ACC), methicillin-susceptible Staphylococcus aureus
(MSSA) and methicillin-resistant S. aureus (MRSA) before cleaning with electrolysed
water. Sites were rescreened at varying intervals from 1- 48 hours after cleaning.
Microbial growth was quantified as cfu/cm2 and presence or not of MSSA and MRSA
for each site. The study was repeated three times at monthly intervals.

The decontamination efficacy of neutral electrolyzed water (NEW) was evaluated using shredded cabbages and carrots in both a scalable laboratory system (experiment I) and an actual processing line in a plant (experiment II). In experiment I, the antimicrobial effect of highly concentrated NEW (up to the maximum regulated level: 200 ppm) was tested to determine the appropriate conditions for use in an actual plant test: (1) hypochlorous acid (HClO) concentration (100, 150, and 200 ppm), (2) ratio of sample weight to NEW volume (1:5, 1:10, and 1:20), and (3) treatment time (5, 10, 20, and 30 min), using 2 kg of shredded cabbages and carrots. In experiment II, the feasibility of the NEW treatment was validated on an actual processing line (treatment unit: 20 kg), including cutting, three washing steps (two air bubble washes for 5 min each and 150 ppm NEW for 5 min at ratio of 1:10), rinsing (5 min), and dehydration (5 min). Overall, the microbial reductions tended to increase as the HClO concentration, ratio of sample to NEW, and treatment time increased. The results obtained from experiment I indicated that the maximum conditions (NEW 200 ppm, 1:20, 30 min) achieved 3.3–3.5 log CFU/g reductions in the coliform counts. After treatment with 200 ppm NEW for > 10 min, however, there were noticeable color changes (color differences, DE > 5.0) in both the shredded cabbages and carrots. In the experiment II, the microbial populations were not affected by cutting and two air bubble treatments, whereas washing with NEW greatly reduced both the aerobic plate counts (1.93–2.17 log CFU/g) and coliform counts (0.97–1.51 log CFU/g). More than 2 log CFU/g of indigenous flora were reduced from raw materials to final products with both shredded cabbages (2.05–2.48 log CFU/g) and carrots (2.34–2.76 log CFU/g). These results may provide useful recommendations for the practical application of highly concentrated NEW in the fresh-cut produce industry to improve the microbiological safety without quality deterioration.

Biofilm formation in dental unit water systems (DUWSs) can contaminate water from three-in-one syringes, air rotors, and low-speed handpieces. This may serve as a potential source of infection for dentists, dental staff, and patients, so these systems must be sterilized. Because slightly acidic electrolyzed water (SAEW) is often used as a disinfectant for food, the aim of this study was to investigate the possibility of using SAEW as a DUWS disinfectant. Slightly acidic electrolyzed water was injected into a dental unit and its effects evaluated. Chemical properties such as chlorine ion and potential hydrogen in the SAEW were measured. Detection of both ordinary and heterotrophic bacteria from the DUWS was performed by culture, and biofilm formation of the bacteria in the DUWS evaluated. Polymerase chain reaction (PCR) was used to detected contamination by nosocomial pathogens. Almost all the chlorine ions in the SAEW were exhausted during the two-day trials, and the pH value of the SAEW fell from 5 to 4. No viable cells were detected in the SAEW collected. Biofilm formation in the water from the DUWS with SAEW was almost at a baseline level, whereas that without SAEW was 4 times higher. The PCR analysis showed that no nosocomial infecting pathogens were detected in the SAEW. The present study demonstrated the antiseptic effect of SAEW in DUWS.

Due to the limitations associated with the use of existing biocidal agents, there is a need to explore new methods of disinfection to help maintain effective bioburden control, especially within the healthcare environment. The transformation of low mineral salt solutions into an activated metastable state, by electrochemical unipolar action, produces a solution containing a variety of oxidants, including hypochlorous acid, free chlorine and free radicals, known to possess antimicrobial properties. Electrochemically activated solutions (ECAS) have been shown to have broad-spectrum antimicrobial activity, and have the potential to be widely adopted within the healthcare environment due to low-cost raw material requirements and ease of production (either remotely or in situ). Numerous studies have found ECAS to be highly efficacious, as both a novel environmental decontaminant and a topical treatment agent (with low accompanying toxicity), but they are still not in widespread use, particularly within the healthcare environment. This review provides an overview of the scientific evidence for the mode of action, antimicrobial spectrum and potential healthcare-related applications of ECAS, providing an insight into these novel yet seldom utilised biocides.

International Journal of Food Engineering is devoted to engineering disciplines related to processing foods. The areas of interest include heat, mass transfer and fluid flow in food processing; food microstructure development and characterization; application of artificial intelligence in food engineering research and in industry; food biotechnology; and mathematical modeling and software development for food processing purposes. Authors and editors come from top engineering programs around the world: the U.S., Canada, the U.K., and Western Europe, but also South America, Asia, Africa, and the Middle East.

The efficacy of mildly heated, slightly acidic electrolyzed water (mildly heated SlAEW) at 45 °C for disinfection and maintenance of sliced carrot quality was studied. Mildly heated SlAEW (23 mg/L available chlorine, pH at 5.5) was used to treat the carrots, followed by rinsing with tap water (TW) for 2 min at 4 °C, and its effectiveness as a disinfectant was evaluated. The physicochemical properties of the carrots were determined and a comparison was made between treatments with SlAEW at room temperature (18 °C), TW at 18 °C and mildly heated TW at 45 °C. Results show that total aerobic bacteria, mold and yeast populations were significantly lower after mildly heated SlAEW treatment. Mildly heated SlAEW treatment reduced the total aerobic bacteria by 2.2 log10 CFU/g and molds and yeasts by >1.9 log10 CFU/g compared with TW treatment. Color indices of hue and chroma of sample surfaces were not affected by mildly heated SlAEW treatment and there were insignificant differences in hardness or the ascorbic acid and β-carotene contents of sliced carrots. The use of mildly heated SlAEW is suggested as an effective disinfection method for fresh cut carrots with low available chlorine.

Bioaerosols in the animal feeding facility might be the potential health risk factors to agricultural workers. A novel on-site membrane-less electrolyzed

water(MLEW) generating and fogging-spread system was designed and installed in selected experimental hen house for evaluating the airborne decontamination efficiency.

The result shows that the bacterial aerosols reached to 10 5 CFU/m 3 levels, 10 min of MLEW fogging-spread operation can has 70% bacterial and fungal aerosols neutralizing efficiency. Index Terms -bioaerosols, membrane-less electrolyzed water, decontamination, hen house.

The effects of 40, 70 or 100 mg L−1 free chlorine neutral and acidic electrolyzed water (NEW and AEW) during the washing and disinfection step, on quality attribute changes during shelf life of fresh-cut mizuna baby leaves, were studied. Physiological, nutritional, enzymatic, sensory, and microbial changes throughout 11 days at 5 °C were monitored. Results were compared to those reached with a conventional industrial treatment of 100 mg L−1 NaClO at pH 6.5 and with a control washing with deionised water. Both NEW and AEW showed an inhibitory effect on natural microflora growth and retained the main quality attributes. Total chlorophyll content was preserved after shelf life. Initial total phenolic contents ranged between 1868 and 2518 mg CAE kg−1 fw for AEW 40 and AEW 100 treatments respectively and slightly increased throughout shelf life. In contrast, after shelf life the total antioxidant activity recorded on the processing day decreased around 35%. Throughout shelf life EW induced an increase in catalase activity while superoxide dismutase activity decreased. Scanning electron microscopy of the leaves showed that neither NEW nor AEW affected their surface structure. To the best of our knowledge, the effects of NEW and AEW on bioactive quality parameters, as well as on antioxidant enzyme activities for fresh-cut baby leaves are first reported here. EW provides an alternative sanitizing technique to NaClO for maintaining the quality of fresh-cut mizuna baby leaves up to 11 days at 5 °C.

The efficacy of mildly heated, slightly acidic electrolyzed water (mildly heated SlAEW) at 45 °C for disinfection and maintenance of sliced carrot quality was studied. Mildly heated SlAEW (23 mg/L available chlorine, pH at 5.5) was used to treat the carrots, followed by rinsing with tap water (TW) for 2 min at 4 °C, and its effectiveness as a disinfectant was evaluated. The physicochemical properties of the carrots were determined and a comparison was made between treatments with SlAEW at room temperature (18 °C), TW at 18 °C and mildly heated TW at 45 °C. Results show that total aerobic bacteria, mold and yeast populations were significantly lower after mildly heated SlAEW treatment. Mildly heated SlAEW treatment reduced the total aerobic bacteria by 2.2 log10 CFU/g and molds and yeasts by >1.9 log10 CFU/g compared with TW treatment. Color indices of hue and chroma of sample surfaces were not affected by mildly heated SlAEW treatment and there were insignificant differences in hardness or the ascorbic acid and β-carotene contents of sliced carrots. The use of mildly heated SlAEW is suggested as an effective disinfection method for fresh cut carrots with low available chlorine.

Lactic acid bacteria isolated from 11 Chinese fermented foods were investigated for their resistance incidences of 7 clinically important antibiotics, including chloramphenicol, kanamycin, tetracycline, ciprofloxacin, ampicillin, clindamicin and erythromycin. It was found that antibiotic resistant lactic acid bacteria are widespread among traditional Chinese fermented foods and their resistance incidences depended on the raw material and manufacturing area of the foods. Resistance incidences of fermented sausages were much higher than that of fermented vegetables. Among 202 antibiotic resistant lactic acid bacterial isolates, 14 were further identified and their minimum inhibitory concentrations against 7 antibiotics were examined. Multi-resistance was observed in these 14 strains, and the presence of genes leading resistance was examined by PCR. Genes tetM and ermB were detected on both plasmid and chromosome in certain strains; gene aphA3 was only detected on plasmid while gene mefA was only on chromosome; genes gyrAblaZ and catpIP501 were not detected. These results indicate the possible role of lactic acid bacteria as reservoirs for dissemination of antibiotic resistance in foods and the environment.

This section covers peculiarities of so-called in-line electrolysis when drinking water is electrolysed to produce disinfection species killing microorganisms. Mainly mixed oxide electrodes (MIO) based on IrO2 and/or RuO2 coatings and boron-doped diamond electrodes were used in the studies. Artificial and real drinking water systems were electrolysed in continuous and discontinuous operating mode, varying water composition, current density and electrode materials. Results show, besides the ability of producing active chlorine, risks of inorganic disinfection by-products (DBPs) such as chlorate, perchlorate, nitrite, ammonium, chloramines, hydrogen peroxide and others. DBPs are responsible for analysis errors using DPD method for active chlorine measurements. Geometry may influence by-product yield. As a conclusion, the necessity of developing test routines for practical cell applications must be underlined.


Effect of Hypochlorous Acid to Reduce Microbial Populations in Dipping
Procedure of Fresh Produce as Saengshik Raw Materials

Pre-treatment steps of fresh produce as Saengshik raw materials are followed by initial clean-up, dipping,
primary washing, and cutting. Hypochlorous acid solution was applied in the dipping step to reduce natural
microflora. Also, procedures were changed by cutting, dipping and then primary washing, and the efficacy of
hypochlorus acid was evaluated. Potatoes, carrots, kales, and angelicas were submerged in water or 100 ppm
of hypochlorous acid for 5 min. After initial clean-up, the aerobic plate counts of potatoes, carrots, kales and
angelicas were 4.7, 5.3, 5.6, and 5.7 log CFU/g, respectively. When samples were submerged into water, it only
reduced the population of natural microflora by 0.2 to 1.1 log CFU/g, whereas when treated with hypochlorous
acid, it reduced the population by 0.5 to 2.8 log CFU/g. Reductions of natural microflora in green leafy vegetables
were more highly achieved than bulbs such as potatoes and carrots. However, the numbers of natural microflora
were increased after cutting step. To control the cross contamination at the cutting process, the process was
changed as follows: initial clean-up, cutting, dipping in hypochlorous acid, and then primary washing. It showed
effective reduction of the population by 2.3 to 3.2 log CFU/g. Hypochlorous acid solution could be useful as
a sanitizer for surface washing of fresh vegetables. 

This study was to investigate the electrolyzed water washing efficiency on the inhibition of bacteria for raw shrimp.The bactericidal activities on raw shrimp treated by four types of electrolyzed water(AEW1,AEW2,MEW1 and MEW2) and two types of organic acid(2%LA and 2%AA) were compared.Sterilize tap water was used as control.The bactericidal activity of on raw shrimp treated with 2%AA was better than electrolyzed water under no vibration condition,Raw shrimp treated with AEW1 was better than 2%AA under vibration condition,tap water treatment was worse than electrolyzed water or organic acid under both no vibration and vibration conditions.Almost no bacterial colony was observed except for tap water.The organoleptic properties of raw shrimp were barely affected by four types of electrolyzed water.The color,odor and overall acceptability of raw shrimp were slightly affected by 2%LA,the odor of raw shrimp was greatly affected by 2%AA,and the muscle tissue and overall acceptability of raw shrimp were slightly affected by 2%AA.Electrolyzed water can be used as cleaning solution to replace tap water in raw shrimp washing in shrimp processing industry.

For the special efficacy of electrolyzed water and the status that electrolyzed water is less studied on leafy vegetables,in order to provide basis for electrolyzed water used in the cultivation of Chinese cabbage and other leafy vegetables,the effect of soaking Chinese cabbage seeds with electrolyzed water was studied under laboratory conditions.The results showed that pH value of the electrolyzed water was an important factor that affected the Chinese cabbage seeds germination.The acidic electrolyzed water of pH 3.30 could accelerate seeds germinating and raise fresh weight of shoots significantly;strong acidic electrolyzed water and alkaline electrolyzed water would slow down the speed of seeds germination and inhibit both germination rate and fresh weight of shoots;besides,neutral electrolyzed water have no clear effect on germination potential,germination rate and fresh weight of shoots.Preliminary view was that,In addition,the results also showed that 2h of soaking time was appropriate;when soaking time was too short,the electrolyzed water could not have any effect,and soaking too long would have a negative effect on the seeds germination.

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Electrolyzed strong acid water (ESAW) is generated by the electrolysis of a weak sodium chloride solution. Although ESAW is known to have a strong bactericidal activity and to be harmless to the living body, its effectiveness and safety in the treatment of perforated peritonitis has not been well established.

Male Wistar rats were used for the study. Three hours after cecal ligation and puncture, the cecum was resected and the peritoneal cavity was irrigated with 50 ml of saline (Group S, n=12) or ESAW (Group E, n=14). The 5-day survival rate was compared between the two groups. In another pair of animals (n=10 each), bacteria in the ascitic fluid were counted at 6 and 18 h after irrigation.

No adverse effects of ESAW were observed in the experimental group. The 5-day survival rate was 25% (3/12) and 85.7% (12/14) in Groups S and E, respectively (P < 0.01). The bacterial count at 18 h after the irrigation in Groups S and E was (5.0 ± 2.5) × 105/ml and (2.2 ± 2.0) × 104/ml, respectively (P < 0.0001).

The ability of activated carbon (AC) prepared from cherry stones (CS) by activation with H3PO4, ZnCl2 or KOH to remove ochratoxin A (OTA) from two Italian red wines has been studied. AC was characterized in terms of texture and surface chemistry. OTA was analyzed by reversed-phase high-performance liquid chromatrography, using a fluorescence detector. The content of OTA in the starting wines is 7.38 and 2.36 μg/L. The adsorption of OTA is high only for one AC, which was prepared by KOH activation at 900 °C, using the 3:1 KOH:CS impregnation ratio. It possesses a large apparent surface area (SBET = 1620 m2/g) and a high volume of large size macropores (1.84 cm3/g). It also contains narrow mesopores and intermediate size and wide micropores. Its content of acidic oxygen surface groups is low, whereas the content of basic groups is high (2.62 meq/g). The treatment of the wines with such an AC results in a decrease of the initial OTA content of more than 50%. However, the changes produced in the total polyphenolic index, color intensity, and hue are small (i.e. ∼8%, ∼5.5% and ∼1.2%, respectively).

The effectiveness of electrolyzed oxidizing anode (EOA) water (oxidation-reduction potential, 1,120 mV; pH 2.0) as a
sanitizer for use in abattoirs was compared with the iodophor (IOD) Mikroklene (25 ppm), a sanitizer approved for use by
regulatory authorities in Canada and the United States. A total of 240 swab (100 cm2) samples were obtained from 4 sites on
the kill floor and 16 sites in the secondary processing areas, during two visits within a 4-week period to each of three meat
packing plants, processing 50 animals per week. Swabs were obtained 12 h after the application of IOD and EOA and were
analyzed for the presence of total aerobic bacteria, total coliforms, and total Escherichia coli. Total aerobic bacteria (log CFU/
100 cm2) recovered from the 20 sample sites were lower (P 0.0001) in EOA as compared with IOD (2.94 0.12 versus
3.75 0.12, respectively). Plant A was 1.5 times more likely (P 0.0001) to have a sampling site positive for the presence
of coliforms and E. coli than plants B and C. There was no difference (P  0.05) between treatment IOD or EOA in the
likelihood of obtaining a positive sample for the presence of total coliforms or E. coli among the three plants. When the kill
floor and secondary processing areas are compared, the likelihood of obtaining a sample positive for coliforms or E. coli was
similar (P 0.05). Results indicate that EOA was more effective than IOD in reducing populations of total aerobic bacteria
on equipment surfaces in the three meat packing plants studied. Because the likelihood of obtaining a positive sample for
coliforms or E. coli in EOA as compared with IOD was similar, EOA may be a suitable alternative or complement to IOD
as a sanitizer in small- to medium-sized abattoirs. Additional research is required to further evaluate the effectiveness of EOA
to sanitize processing equipment on the basis of subsequent isolation of aerobes, coliforms, and E. coli from meat product

Among different fish slices used for sashimi preparation, tuna is the most popular and preferable fish type for Taiwanese people. To improve the hygienic quality of fish slices, electrolyzed (EO) water containing 10, 50, and 100 mg/L chlorine, was used in combination with CO gas treatment. Effect of different treatment on aerobic plate count (APC), volatile basic nitrogen (VBN), K value, and Hunter L*, a*, b* values of yellow-fin tuna steak during storage (4 °C and −20 °C) were evaluated. It was found that APC, VBN, and K values increased with storage time for all treatment. Except for K value, APC and VBN of tuna steak treated with the combination of more than 50 mg/L chlorine EO water and CO gas had the lowest value after 8 d of refrigerated storage. Hunter a* value of tuna steak treated with only CO gas was the highest, followed by those treated with EO water and CO gas. These results demonstrated that EO water containing 50 mg/L chlorine combined with CO gas treatment in tuna fish steak would be an effective method for enhancing the hygienic quality and freshness for tuna meat and extending refrigerated storage time. Tuna treated with EO water containing 100 mg/L chlorine and CO gas combination had the lowest APC immediately after treatment and reduced further to below detection limit after 1 mo frozen storage at −20 °C.

Electrolysed oxidizing (EO) water is produced by passing a DC current through a weak sodium chloride solution, resulting in alkaline and acidic EO water. The goal of this research was to determine whether EO water could be used as an acceptable cleaning and disinfecting agent for materials used in pipeline milking systems. Small pieces of materials commonly used in milking systems were soiled using raw milk inoculated with a cocktail of four bacterial cultures similar to those commonly found in raw milk, and then cleaned by soaking in alkaline EO water followed by soaking in acidic EO water at various treatment times and temperatures. Effective treatment time and temperature combinations were determined by response surface design for a temperature range of 25–60°C and a time range of 5–20 min. Treated materials were evaluated by aerobic plate counts and ATP bioluminescence to assess the disinfecting and cleaning effectiveness of EO water. Most of the treatments at 60°C and several treatments at lower temperatures successfully removed all detectable bacteria and ATP. Overall, the results of this study indicated that EO water has the potential to be used as a cleaning and disinfecting agent for materials used in milking systems.

Efficacy of Ozonated and Electrolyzed Oxidative Waters To
Decontaminate Hides of Cattle before Slaughter

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 158C for 10 s. Alkaline EO water and acidic EO water were sequentially
applied at 608C 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.

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.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.

Decontamination effect of electrolysed NaCl solutions on carpB.S.M. Mahmoud1, K. Yamazaki2, K. Miyashita1, S. Il-Shik3, C. Dong-Suk4and T. Suzuki2Laboratories of1Bioresources Chemistry, and2Marine Food Science, Graduate School of Fisheries Science, Hokkaido University,Minato, Hakodate, Japan,3Faculty of Marine Bioscience, Kangnung National University, Kangnung, Korea, and4College of FisheriesScience, Pukyong National University, Busan, Korea2004/0109: received 3 February 2004, revised 22 April 2004 and accepted 30 April 2004ABSTRACTB . S . M . M A H M O U D , K . Y A M A Z A K I , K . M I Y A S H I T A , S . I L – S H I K , C . D O N G – S U K A N D T . S U Z U K I . 2004.Aims: To evaluate the efficacy of electrolysed NaCl solutions (EW) for disinfecting bacterial isolates from carp, andthe potential application of EW to reducing the bacterial load in whole carp and carp fillets.Methods and Results: EW was produced by using a two-compartment batch-type electrolysed apparatus.Pure cultures (in vitro), whole carp (skin surface) and carp fillets were treated with EW to detect its antimicrobialeffects. The anodic solution [EW (+)] completely inhibited growth of the isolates. Furthermore, dipping thefish samples in EW (+) reduced the mean total count of aerobic bacteria on the skin of whole carp and in fillets by2Æ8 and 2Æ0 log10, respectively. The cathodic solution [EW ())] also reduced growth of the isolates from carp byca 1Æ0 log10. Moreover, the total counts of aerobic bacteria in whole carp (on the skin) and fillets were reduced by1Æ28 and 0Æ82 log10, respectively

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.

Electrolyzed oxidizing (EO) water has been regarded as a new sanitizer in recent years. Production of EO water needs only water and salt (sodium chloride). EO water have the following advantages over other traditional cleaning agents: effective disinfection, easy operation, relatively inexpensive, and environmentally friendly. The main advantage of EO water is its safety. EO water which is also a strong acid, is different to hydrochloric acid or sulfuric acid in that it is not corrosive to skin, mucous membrane, or organic material. Electrolyzed water has been tested and used as a disinfectant in the food industry and other applications. Combination of EO water and other measures are also possible. This review includes a brief overview of issues related to the electrolyzed water and its effective cleaning of food surfaces in food processing plants and the cleaning of animal products and fresh produce.

 The purpose of the study was to determine whether electrolyzed oxidized water (EOW) functions as a bactericide in burn injury with Pseudomonas aeruginosa infection in a rat burn-wound model.Sprague-Dawley rats (n = 31) were subjected to third-degree burns to 30% of total body surface area. Two days after injury, all rats were infected with P. aeruginosa using 1 mL of a suspension containing 1 x 10(8) colony-forming units. Rats were assigned to one of three groups: no irrigation (group I), irrigation with physiologic saline (group II), or irrigation with EOW (group III). Blood culture, endotoxin levels, and survival rates were determined. Survival rate was significantly higher in group III than in groups I or II (p < 0.0001). Serum endotoxin levels on day 3 after infection in group III were significantly lower than the levels in group I (p < 0.01) and group II (p < 0.01). There were significant differences between the three groups in the culture of P. aeruginosa (p < 0.05).Irrigation and disinfection with EOW may become useful in preventing burn-wound sepsis.

The Effect of Available Chlorine Concentration on the Disinfecting Potential
of Acidic Electrolyzed Water for Shredded Vegetables

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 (0.4ppm). The similar effect was detected in AcEW with 0ppm 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. 

The purposes of this study were to examine the time-related changes in pH, oxidation-reduction potential, and concentration of chlorine of electrolyzed neutral water and to evaluate the bactericidal effect of electrolyzed neutral water against bacteria from infected root canals. Study Design. Various properties of electrolyzed neutral water—pH value, oxidation-reduction potential, and concentration of chlorine—were measured at different times after storage of the water in the open state, the closed state, or the closed-and-dark state. The bactericidal effect of the various electrolyzed neutral water samples was then tested against 17 strains of bacteria, including 15 strains isolated from infected canals, as well as against 1 strain of fungus. Each bacterial or fungal suspension was mixed with electrolyzed neutral water, and the 2 substances were reacted together for 1 minute. After incubation for 1 to 7 days, the bactericidal effect of the electrolyzed neutral water was determined. Results. The pH value and oxidation-reduction potential of electrolyzed neutral water remained almost unchanged when the water was stored in a dark, closed container. However, the concentration of chlorine decreased from 18.4 ppm to 10.6 ppm. Electrolyzed neutral water showed a bactericidal or growth-inhibitory effect against the bacteria. Conclusions. The results indicate that electrolyzed neutral water maintains a constant pH and oxidation-reduction potential when kept in a closed container without light and that it exhibits a bacteriostatic/bactericidal action against isolates obtained from infected root canals.The purposes of this study were to examine the time-related changes in pH, oxidation-reduction potential, and concentration of chlorine of electrolyzed neutral water and to evaluate the bactericidal effect of electrolyzed neutral water against bacteria from infected root canals .

Electrolyzed Water as a Disinfectant
for Fresh-cut Vegetables

The effect of electrolyzed water on total microbial count was
evaluated on several fresh-cut vegetables. When fresh-cut
carrots, bell peppers, spinach, Japanese radish, and potatoes were treated with electrolyzed water (pH 6.8, 20 ppm
available chlorine) by dipping, rinsing, or dipping/blowing, microbes on all cuts were reduced by 0.6 to 2.6 logs CFU/g.
Rinsing or dipping/blowing were more effective than dipping.
Electrolyzed water containing 50 ppm available chlorine had
a stronger bactericidal effect than that containing 15 or 30
ppm chlorine for fresh-cut carrots, spinach, or cucumber.
Electrolyzed water did not affect tissue pH, surface color, or
general appearance of fresh-cut vegetables.
Key words: freshcut vegetables, electrolyzed water, disinfectant, chlorine, microbes food additives in 1991 due to lack of use at that time. Thus, it appears
that use of electrolyzed water would be presently constrained legally.
Hypochlorous acid is present in electrolyzed water, which is generated from the reaction of Cl2 and H2O in an anode site when NaCl
solution ,10% is electrolyzed through a septum. This results in acid
water with pH of 2 to 3. Neutral water at pH 6.8 is generated by
electrolysis of NaCl solution without a septum, because HCl formed
at the anode site neutralizes the NaOH at the cathode site (Hirano and
Ueda, 1997). The objective of this work was to determine the effectiveness of electrolyzed neutral water as a source of hypochlorous
acid to control microbial populations of fresh-cut vegetables

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.

 Milking systems, electrolyzed oxidizing water, CIP, clean in place, ATP bioluminescence

Electrolyzed oxidizing (EO) water is a technology that electrolyzes a weak sodium chloride solution into sodium and chlorine, resulting in two solutions alkaline and acid. The goal of this research is to determine if EO water is an acceptable cleaning agent for pipeline milking systems. After constructing 1.5 inch-diameter pipeline milking system, the system was soiled using raw milk that had been spiked with common raw milk microorganisms. After soiling, the system was rinsed with warm water and then evaluated in several locations for initial counts. To evaluate the level of soiling, the surfaces were evaluated using an ATP bioluminescence method. The milk contact surfaces were also swabbed for microbial analysis. The pipeline system was then washed with an alkaline EO water treatment followed by an acidic EO water treatment. After treatment, the effectiveness of the treatment was evaluated by ATP bioluminescence and microbiological analysis. First, a 10 min wash with 60C alkaline water followed by a 10 min wash with 60C acid water successfully removed all detectable bacteria and ATP from the non-porous milk contact surfaces. Shorter treatment times (5 and 7.5 min) with EO water were also tested, along with a control treatment using conventional dairy cleaning chemicals. Using ANOVA, there were no significant differences between the EO water treatments and the conventional treatment, however the 5-min EO water treatment was significantly less effective than the 10-min treatment.

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