Vibrio spp

Journal of food science and technology 54.5 (2017): 1321-1332
Application of electrolysed oxidising water as a sanitiser to extend the shelf-life of seafood products: a review
Electrolysed oxidising water (E.O. water) is produced by electrolysis of sodium chloride to yield primarily chlorine based oxidising products. At neutral pH this results in hypochlorous acid in the un-protonated form which has the greatest oxidising potential and ability to penetrate microbial cell walls to disrupt the cell membranes. E.O. water has been shown to be an effective method to reduce microbial contamination on food processing surfaces. The efficacy of E.O. water against pathogenic bacteria such as Listeria monocytogenes, Escherichia coli and Vibrio parahaemolyticus has also been extensively confirmed in growth studies of bacteria in culture where the sanitising agent can have direct contact with the bacteria. However it can only lower, but not eliminate, bacteria on processed seafoods. More research is required to understand and optimise the impacts of E.O. pre-treatment sanitation processes on subsequent microbial growth, shelf life, sensory and safety outcomes for packaged seafood products.
Frontiers in Microbiology 7 (2016): 305
Acidic Electrolyzed Water as a Novel Transmitting Medium for High Hydrostatic Pressure Reduction of Bacterial Loads on Shelled Fresh Shrimp
Acidic electrolyzed water (AEW), a novel non-thermal sterilization technology, is widely used in the food industry. In this study, we firstly investigated the effect of AEW as a new pressure transmitting medium for high hydrostatic pressure (AEW-HHP) processing on microorganisms inactivation on shelled fresh shrimp. The optimal conditions of AEW-HHP for Vibrio parahaemolyticus inactivation on sterile shelled fresh shrimp were obtained using response surface methodology: NaCl concentration to electrolysis 1.5 g/L, treatment pressure 400 MPa, treatment time 10 min. Under the optimal conditions mentioned above, AEW dramatically enhanced the efficiency of HHP for inactivating V. parahaemolyticus and Listeria monocytogenes on artificially contaminated shelled fresh shrimp, and the log reductions were up to 6.08 and 5.71 log10 CFU/g respectively, while the common HHP could only inactivate the two pathogens up to 4.74 and 4.31 log10 CFU/g respectively. Meanwhile, scanning electron microscopy (SEM) showed the same phenomenon. For the naturally contaminated shelled fresh shrimp, AEW-HHP could also significantly reduce the micro flora when examined using plate count and PCR-DGGE. There were also no significant changes, histologically, in the muscle tissues of shrimps undergoing the AEW-HHP treatment. In summary, using AEW as a new transmitting medium for HHP processing is an innovative non thermal technology for improving the food safety of shrimp and other aquatic products.
International journal of food microbiology 231 (2016): 48-53
Effect of acidic electrolyzed water-induced bacterial inhibition and injury in live clam (Venerupis philippinarum) and mussel (Mytilus edulis)
The effect of acidic electrolyzed water (AEW) on inactivating Escherichia coli O104:H4, Listeria monocytogenes, Aeromonas hydrophila, Vibrio parahaemolyticus and Campylobacter jejuni in laboratory contaminated live clam (Venerupis philippinarum) and mussel (Mytilus edulis) was investigated. The initial levels of bacterial contamination were: in clam 4.9 to 5.7 log10 CFU/g, and in mussel 5.1 to 5.5 log10 CFU/g. Two types of AEW were used for treatment time intervals of 1 and 2 h: strong (SAEW) with an available chlorine concentration (ACC) of 20 mg/L, pH = 3.1, and an oxidation-reduction potential (ORP) of 1150 mV, and weak (WAEW) at ACC of 10 mg/L, pH = 3.55 and ORP of 950 mV. SAEW and WAEW exhibited significant inhibitory activity against inoculated bacteria in both shellfish species with significant differences compared to saline solutions treatments (1–2% NaCl) and untreated controls (0 h). SAEW showed the largest inhibitory activity, the extent of reduction (log10 CFU/g) ranged from 1.4–1.7 for E. coli O104:H4; 1.0–1.6 for L. monocytogenes; 1.3–1.6 for A. hydrophila; 1.0–1.5 for V. parahaemolyticus; and 1.5–2.2 for C. jejuni in both types of shellfish. In comparison, significantly (P < 0.05) lower inhibitory effect of WAEW was achieved compared to SAEW, where the extent of reduction (log10 CFU/g) ranged from 0.7–1.1 for E. coli O104:H4; 0.6–0.9 for L. monocytogenes; 0.6–1.3 for A. hydrophila; 0.7–1.3 for V. parahaemolyticus; and 0.8–1.9 for C. jejuni in both types of shellfish. Among all bacterial strains examined in this study, AEW induced less bacterial injury (~ 0.1–1.0 log10 CFU/g) and more inactivation effect. This study revealed that AEW (10–20 mg/L ACC) could be used to reduce bacterial contamination in live clam and mussel, which may help control possible unhygienic practices during production and processing of shellfish without apparent changes in the quality of the shellfish.
Food and bioprocess technology 8.8 (2015): 1762-1770
Reduction of Escherichia coli and Vibrio parahaemolyticus Counts on Freshly Sliced Shad (Konosirus punctatus) by Combined Treatment of Slightly Acidic Electrolyzed Water and Ultrasound Using Response Surface Methodology
The aim of this study was to determine the combined effects of slightly acidic electrolyzed water [SAEW (pH range 5.0–6.5, oxidation–reduction potential 650–1000 mV, available chlorine concentration 10–80 mg/L)] containing 0, 15, and 30 ppm chlorine and 0, 50, and 100 min of ultrasound [US (37 kHz, 380 W)] using the central composite design (CCD) on the reductions of Escherichia coli and Vibrio parahaemolyticus (initial value, approximately 6–7 log10 colony forming unit (CFU) of E. coli or V. parahaemolyticus/g) and the sensory properties on freshly sliced shad (Konosirus punctatus), in comparison with SAEW or US alone. Another aim was to develop the response surface model for E. coli and V. parahaemolyticus in the shad treated with the combination of SAEW and US. Single treatments with SAEW (chlorine 15 ppm), SAEW (chlorine 30 ppm), or US for 50 min caused a much-less-than-1-log10 reduction in the number of both E. coli and V. parahaemolyticus in the shad. In contrast, the combination of SAEW (15 or 30 ppm chlorine) and US (50 or 100 min) caused >1-log10 reduction of E. coli numbers (1.04–1.86 log reduction) and V. parahaemolyticus (1.02–1.42 log reduction) in the shad. In addition, the sensory properties of the shad were not changed under the harshest conditions of the combination (SAEW with chlorine at 30 ppm and US for 100 min). Response surface models were developed for the population of E. coli (Y = 6.15322 − 0.024732X 1 − 0.016486X 2 − 0.00015X 1 X 2 + 0.00024X 1 2 + 0.00007X 2 2) and V. parahaemolyticus (Y = 5.67649 − 0.042598X 1 − 0.014013X 2 + 0.00003X 1 X 2 + 0.00006X 1 2 + 0.00062X 2 2 ), where Y is the bacterial population (log10 CFU), X 1 is ppm chlorine in SAEW, and X 2 is the duration of treatment (min) with US. The appropriateness of the models was verified by bias factor (B f; 1.10 for E. coli, 1.03 for V. parahaemolyticus), accuracy factor (A f; 1.11 for E. coli, 1.05 for V. parahaemolyticus), mean square error (MSE; 0.0087 for E. coli, 0.0028 for V. parahaemolyticus), and coefficient of determination (R 2; 0.976 for E. coli, 0.982 for V. parahaemolyticus). To produce a 1-log10 reduction of E. coli and V. parahaemolyticus, US treatment times for E. coli and V. parahaemolyticus were calculated within the maximum of 54 and 67 min, respectively, at chlorine 10 ppm in SAEW. SAEW chlorine concentrations (ppm) for E. coli and V. parahaemolyticus were calculated within the maximum of 38 and 41 ppm, respectively, at 20 min of US. Therefore, the resulting response surface models for E. coli and V. parahaemolyticus should be further validated on slices of other kinds of raw fish. Ultimately, the response surface quadratic polynomial equations may thus be used for predicting the combined treatments of SAEW and against E. coli and V. parahaemolyticus in raw fish production, processing, and distribution.
Korean Journal of Food Science and Technology 47.6 (2015): 719-724

Bactericidal Effects of Hypochlorous Acid Water against Vibrio parahaemolyticus Contaminated on Raw Fish and Shellfish

The bactericidal effects of strongly acidic hypochlorous acid water (StAHA) and slightly acidic hypochlorous acid water (SlAHA) against Vibrio parahaemolyticus contaminated on surface of raw fish and shellfish were examined. V. parahaemolyticus contaminated with about 7.0 log CFU/g on the meat chunk of olive flounder (Paralichthys olivaceus), and yellow tail (Seriola quinqueradiata), and 4.0 log CFU/g on the shucked scallop (Patinopecten yessoensis) were not detected after washing with StAHA and SlAHA at a ratio of 30:1 on a sample weight basis. However, 1.0 log CFU/g of V. parahaemolyticus was survived on shucked oyster (Crassostrea gigas) under same treatment conditions. The bactericidal effects of acidic hypochlorous acid water against V. parahaemolyticus contaminated on surface of shucked oyster were not as effective as those against V. parahaemolyticus contaminated on surface of meat chunk of olive flounder, yellow tail, and shucked scallop. Such differences can be attributed to the complicated surface conformation of oyster.

Food Control 53 (2015): 117-123

Efficacy of acidic and alkaline electrolyzed water for inactivating Escherichia coli O104:H4, Listeria monocytogenes, Campylobacter jejuni, Aeromonas hydrophila, and Vibrio parahaemolyticus in cell suspensions

This study investigated the effect of electrolyzed water on pathogenic bacteria cell suspensions. Specifically, we evaluated the efficacy of strong and weak acidic electrolyzed waters (SACEW, WACEW) and strong and weak alkaline electrolyzed waters (SALEW, WALEW) on Vibrio parahaemolyticus, Listeria monocytogenes, Aeromonas hydrophila, Campylobacter jejuni, and Escherichia coli O104:H4 in suspensions of (107–109 CFU/mL) in 1% NaCl. SACEW and WACEW were applied at available chlorine concentrations (ACC) of 20 and 10 mg/mL, pH 3.1 and 3.55 and oxidation-reduction potentials (ORP) of 1150 and 950 mV, respectively. Results show that no viable cells were recovered for V. parahaemolyticus, L. monocytogenes, A. hydrophila, C. jejuni within 2 min at 20 °C. However, E. coli O104:H4 was significantly more resistant to ALEW compared to ACEW. Results also show that the bactericidal activity of SACEW (20 mg/mL ACC) was more effective than WACEW (10 mg/mL ACC) in terms of inactivating E. coli O104:H4. Alkaline-electrolyzed waters were found to reduce cell numbers by 1–3 log (P < 0.05). However, alkaline electrolyzed water was less effective (P < 0.05) than acidic electrolyzed treatment.

Journal of food protection 77.12 (2014): 2176-2180

Efficacy of Neutral Electrolyzed Water for Reducing Pathogenic Bacteria Contaminating Shrimphttps

Pathogenic contamination is a food safety concern. This study was conducted to investigate the efficacy of neutral electrolyzed water (NEW) in killing pathogens, namely, Vibrio parahaemolyticus, Vibrio vulnificus, Salmonella Enteritidis, and Escherichia coli in shrimp. Pure cultures of each pathogen were submerged separately in NEW containing five different chlorine concentrations: 10, 30, 50, 70, and 100 ppm. For each concentration, three submersion times were tested: 1, 3, and 5 min. The population of V. parahaemolyticus was rapidly reduced even at low concentrations, but prolonged contact times caused only a slight reduction. V. vulnificus was gradually inhibited with increasing NEW concentrations and contact times. For the V. parahaemolyticus applications of 70 ppm for 5 min and of 100 ppm for 3 min, each eliminated 7 log CFU/ml. For V. vulnificus, applications of 50 ppm for 3 min and 100 ppm for 1 min, each eliminated 7 log CFU/ml. Salmonella Enteritidis and E. coli were slightly reduced by NEW. Applications of 50 ppm for 15 min and 10 ppm for 30 min completely eliminated 4.16 log CFU/g of V. parahaemolyticus in inoculated shrimp, while only a 1-log CFU/g reduction of V. vulnificus was detected. Soaking shrimp in 10 ppm NEW for 30 min did not affect its sensory quality. Our results suggest NEW could be an alternative sanitizer to improve the microbiological quality of seafood.

Food Control 36.1 (2014): 273-279

Modeling Vibrio parahaemolyticus inactivation by acidic electrolyzed water on cooked shrimp using response surface methodology

Thus, V. parahaemolyticus has become the predominant harmful factor of raw shrimp (Pu et al., 2013;Su and Liu, 2007). Additionally, cooked shrimp are often picked by hand, and also can be easily contaminated with V. parahaemolyticus through bad manufacturing practices and poor personal hygiene McCarthy, 1997;Wang et al., 2014) during each course including storage, transportation and distribution (Dupard et al., 2006;Gudbjorndottir et al., 2005). Moreover, risk assessment of V. parahaemolyticus on cooked black tiger shrimp has been conducted in Malaysia in 2008 and 2012, and the results showed that consuming cooked shrimp could cause illness related with V. parahaemolyticus (Sani et al., 2012(Sani et al., , 2008. …
… Moreover, risk assessment of V. parahaemolyticus on cooked black tiger shrimp has been conducted in Malaysia in 2008 and 2012, and the results showed that consuming cooked shrimp could cause illness related with V. parahaemolyticus (Sani et al., 2012(Sani et al., , 2008. Therefore, food scientists and food industry are searching for novel non-thermal methods that could destroy undesired microorganisms with less adverse effects on products (Ju et al., 2008;Wang et al., 2014). …
… Several studies have been performed on non-thermal methods for decontaminating bacteria on fresh produce, such as organic acids, compounds of chlorine, pulsed electric field (PEF), etc. (Ding et al., 2010;Huang et al., 2014;Pipek et al., 2006). Acidic electrolyzed water (AEW) is regarded as one of the most promising, with a high efficacy for inactivating food-borne pathogens (Ding et al., 2010;Wang et al., 2014). It has been demonstrated that AEW has a strong disinfectant effect on V. parahaemolyticus.

International Journal of Food Microbiology 179 (2014): 50-56

Fate of Vibrio parahaemolyticus on shrimp after acidic electrolyzed water treatment

The objective of this study was to investigate the fate of Vibrio parahaemolyticus on shrimp after acidic electrolyzed water (AEW) treatment during storage. Shrimp, inoculated with a cocktail of four strains of V. parahaemolyticus, were stored at different temperatures (4–30 °C) after AEW treatment. Experimental data were fitted to modified Gompertz and Log-linear models. The fate of V. parahaemolyticus was determined based on the growth and survival kinetics parameters (lag time, λ; the maximum growth rate, μmax; the maximum growth concentration, D; the inactivation value, K) depending on the respective storage conditions. Moreover, real-time PCR was employed to study the population dynamics of this pathogen during the refrigeration temperature storage (10, 7, 4 °C). The results showed that AEW treatment could markedly (p < 0.05) decrease the growth rate (μmax) and extend the lag time (λ) during the post-treatment storage at 30, 25, 20 and 15 °C, while it did not present a capability to lower the maximum growth concentration (D). AEW treatment increased the sensitivity of V. parahaemolyticus to refrigeration temperatures, indicated by a higher (p < 0.05) inactivation value (K) of V. parahaemolyticus, especially for 10 °C storage. The results also revealed that AEW treatment could completely suppress the proliferation of V. parahaemolyticus in combination with refrigeration temperature. Based on above analysis, the present study demonstrates the potential of AEW in growth inhibition or death acceleration of V. parahaemolyticus on seafood, hence to greatly reduce the risk of illness caused by this pathogen during post-treatment storage.

Food Control 23.2 (2012): 320-324

Combining basic electrolyzed water pretreatment and mild heat greatly enhanced the efficacy of acidic electrolyzed water against Vibrio parahaemolyticus on shrimp

The objective of this study was to investigate the efficacy of acidic electrolyzed water (AEW) against Vibrio parahaemolyticus on shrimp. The shrimp was initially inoculated with V. parahaemolyticus(7–8 log CFU/g), and treated with AEW (AEW1 containing 51 mg/L of chlorine or AEW2 containing 78 mg/L of chlorine) or organic acids (2% AA and 2%LA) for 1 min or 5 min under different treated conditions. The effect of AEW was better than that of organic acids, the number of survival V. parahaemolyticus cells on shrimp was reduced by 0.9 log CFU/g after treatment for 5 min with AEW without vibration, while 1.0 log CFU/g bacteria cells reduced with vibration. No significant difference (p > 0.05) was observed between AEW and organic acids in the bactericidal activity with or without vibration. The effective order of temperatures on bactericidal activities of AEW was 50 °C > 20 °C > 4 °C, and a 3.1 log CFU/g reduction of V. parahaemolyticus cells on shrimp was detected with treatment of AEW at 50 °C. Mild heat greatly enhanced efficacy of electrolyzed water against V. parahaemolyticus. Basic electrolyzed water (BEW) (50 °C) pretreatment combined with AEW (50 °C) treatment remarkably reduced bacterial cells by 5.4 log CFU/g on shrimp after treatment for 5 min. There was a significant change in physicochemical properties (pH, ORP, ACC) of AEW, after it was used to wash shrimp (P < 0.05). This study suggests that BEW (50 °C) pretreatment followed by AEW (50 °C) treatment could be a possible method to effectively control V. parahaemolyticus contamination on shrimp.

Food Research International 47.2 (2012): 331-336

Physicochemical properties and bactericidal activities of acidic electrolyzed water used or stored at different temperatures on shrimp

The objective of this study was to evaluate physicochemical properties and bactericidal activities of acidic electrolyzed water (AEW) used or stored at different temperatures on shrimp. Three independent experiments were carried out. The first experiment was to evaluate the physicochemical properties and bactericidal activities of AEW used at three different temperatures (4, 20, 50 °C) against food-borne pathogens (Listeria monocytogenes and Vibrio parahaemolyticus) contamination on cooked shrimp at 1 or 5 min; the second one was to monitor the bactericidal activity of AEW used at two temperatures (20, 50 °C) against total aerobic bacteria on raw shrimp at 5 min by conventional plate count method and PCR–DGGE method; the last one was to examine the physicochemical properties and bactericidal activities of AEW (AEW1, AEW2) stored at two temperatures (− 18, 25 °C) for 30 d against total aerobic bacteria on raw shrimp at 2 min. Results showed that AEW used at 50 °C showed the best bactericidal activity, leading to a log reduction of 3.11 for V. parahaemolyticus, 1.96 for L. monocytogenes and 1.44 for total aerobic bacteria at 5 min, respectively. Conventional plate count and PCR–DGGE (denaturing gradient gel electrophoresis) study further suggested that the bactericidal activity of AEW used at 50 °C was higher than at 20 °C. The loss of bactericidal activity of AEW stored at − 18 °C was less than that of stored at 25 °C, and the ORP and ACC decreased more slowly than those of stored at 25 °C. However, the ORP and ACC of AEW used at 50 °C showed a remarkably faster decrease than that of used at 20 °C. We suggest using AEW at 50 °C to enhance bactericidal activity and storing at − 18 °C to keep the content of ACC and the bactericidal activity.

Letters in applied microbiology 43.6 (2006): 666-672

Efficacy of electrolysed oxidizing water in inactivating Vibrio parahaemolyticus on kitchen cutting boards and food contact surfaces

Aim: To determine the efficacy of electrolysed oxidizing (EO) water in inactivating Vibrio parahaemolyticus on kitchen cutting boards and food contact surfaces.

Methods and Results: Cutting boards (bamboo, wood and plastic) and food contact surfaces (stainless steel and glazed ceramic tile) were inoculated with V. parahaemolyticus. Viable cells of V. parahaemolyticus were detected on all cutting boards and food contact surfaces after 10 and 30 min, respectively, at room temperatures. Soaking inoculated food contact surfaces and cutting boards in distilled water for 1 and 3 min, respectively, resulted in various reductions of V. parahaemolyticus, but failed to remove the organism completely from surfaces. However, the treatment of EO water [pH 2·7, chlorine 40 ppm, oxidation-reduction potential 1151 mV] for 30, 45, and 60 s, completely inactivated V. parahaemolyticus on stainless steel, ceramic tile, and plastic cutting boards, respectively.

Conclusions: EO water could be used as a disinfecting agent for inactivating V. parahaemolyticus on plastic and wood cutting boards and food contact surfaces.

Significance and Impact of the study: Rinsing the food contact surfaces with EO water or soaking cutting boards in EO water for up to 5 min could be a simple strategy to reduce cross-contamination of V. parahaemolyticus during food preparation.

Clinical Ophthalmology (Auckland, NZ) 11 (2017): 707

Reduction in bacterial load using hypochlorous acid hygiene solution on ocular skin

Purpose

To examine the magnitude of bacterial load reduction on the surface of the periocular skin 20 minutes after application of a saline hygiene solution containing 0.01% pure hypochlorous acid (HOCl).
Methods

Microbiological specimens were collected immediately prior to applying the hygiene solution and again 20 minutes later. Total microbial colonies were counted and each unique colony morphology was processed to identify the bacterial species and to determine the susceptibility profile to 15 selected antibiotics.
Results

Specimens were analyzed from the skin samples of 71 eyes from 36 patients. Prior to treatment, 194 unique bacterial isolates belonging to 33 different species were recovered. Twenty minutes after treatment, 138 unique bacterial isolates belonging to 26 different species were identified. Staphylococci accounted for 61% of all strains recovered and Staphylococcus epidermidis strains comprised 60% of the staphylococcal strains. No substantial differences in the distribution of Gram-positive, Gram-negative, or anaerobic species were noted before and after treatment. The quantitative data demonstrated a >99% reduction in the staphylococcal load on the surface of the skin 20 minutes following application of the hygiene solution. The total S. epidermidis colony-forming units were reduced by 99.5%. The HOCl hygiene solution removed staphylococcal isolates that were resistant to multiple antibiotics equally well as those isolates that were susceptible to antibiotics.
Conclusion

The application of a saline hygiene solution preserved with pure HOCl acid reduced the bacterial load significantly without altering the diversity of bacterial species remaining on the skin under the lower eyelid.

Food control 60 (2016): 505-510

Disinfection efficacy and mechanism of slightly acidic electrolyzed water on Staphylococcus aureus in pure culture

Slightly acidic electrolyzed water (SAEW), considered as a broad-spectrum and high-performance bactericide are increasingly applied in the food industry. However, its disinfection mechanism has not been completely elucidated. This study aims to examine the disinfection efficacy and mechanism of SAEW on Staphylococcus aureus, compared with that of sodium hypochlorite (NaClO) and hydrochloric acid (HCl). SAEW treatment significantly reduced S. aureus by 5.8 log CFU/mL in 1 min, while 3.26 and 2.73 log reductions were obtained with NaClO and HCl treatments, respectively. A series of biological changes including intracellular potassium leakage, TTC-dehydrogenase relative activity and bacterial ultrastructure destruction were studied following disinfection treatment of S. aureus. The results showed that SAEW decreased the relative activity of TTC-dehydrogenase by 65.84%. Comparing intracellular potassium leakage, the SAEW treatment caused a greater percent of protein leakage (108.34%) than the NaClO (18.75%) or HCl (0.84%) treatments. These results demonstrated the potent impact SAEW had on the permeability of cell membranes. In addition, the ranking of partly agglutinated cellular inclusion formation was HCl > SAEW > NaClO. It appeared that HCl, along with its low pH value, are responsible for most of the cytoplasmic disruptions. Overall, this study demonstrated that the disinfection mechanism of SAEW was disrupting the permeability of cell membrane and the cytoplasmic ultrastructures in S. aureus cells.

Polymers 7.12 (2015): 2638-2649

Open AccessArticle
Physicochemical and Antibacterial Properties of Carrageenan and Gelatine Hydrosols and Hydrogels Incorporated with Acidic Electrolyzed Water

The article focuses on investigation of the effects of usage of acidic electrolyzed water (AEW) with different sodium chloride concentration (0.001%, 0.01%, and 0.1%) for the preparation of carrageenan and gelatine hydrosols and hydrogels. To determine physiochemical properties of hydrosols, the pH, oxidation-reduction potential (ORP), available chloride concentration (ACC) and rheological parameters such us gelation and flow temperatures were measured. The samples were also characterized using Fourier transform infrared spectroscopy (FT IR) and texture profile analysis (TPA). Additionally, the article contains an analysis of antibacterial activity of carrageenan and gelatine hydrosols incorporated with acidic electrolyzed water, against Staphylococcus aureus and Escherichia coli. The FT IR spectra demonstrated that the structure of gelatine and carrageenan are not significantly affected by electrolyzed NaCl solution components. Furthermore, TPA analysis showed that the use of AEW did not cause undesirable changes in hydrogels layer. The microbiological analysis confirmed inhibition of bacterial growth by hydrosols to about 2.10 log reduction. The results showed that the range of reduction of microorganisms depends on the type AEW used. This might be explained by the fact that the lowest pH and the highest ACC values of hydrosols were obtained for samples with the longest period of exposure to electrolysis (10 min) and the highest amount of NaCl (0.1% w/v). These results suggest that hydrogels and hydrosols incorporated with AEW may be used for food preservation.

Poultry science 94.11 (2015): 2838-2848

Poultry Science
An official journal of the Poultry Science Association.

First self-published in 1921, Poultry Science is an internationally renowned monthly journal, known as the authoritative source for a broad range of poultry information and high-caliber research. The journal plays a pivotal role in the dissemination of preeminent poultry-related knowledge across all disciplines. Poultry Science is an Open Access journal with no subscription charges, meaning authors who publish here can make their research immediately, permanently, and freely accessible worldwide while retaining copyright to their work.

An international journal, Poultry Science publishes original papers, research notes, symposium papers, and reviews of basic science as applied to poultry. This authoritative source of poultry information is consistently ranked by Clarivate’s Impact Factor as one of the top 10 agriculture, dairy and animal science journals to deliver high-caliber research. Currently it is the highest-ranked (by Impact Factor and Eigenfactor) journal dedicated to publishing poultry research. Subject areas include breeding, genetics, education, production, management, environment, health, behavior, welfare, immunology, molecular biology, metabolism, nutrition, physiology, reproduction, processing, and products.

International journal of clinical and experimental medicine 8.7 (2015): 11463

An ınvestigation into the in-vitro effectiveness of electrolyzed water against various microorganisms

The aim of this study was to investigate the in-vitro antimicrobial activity of usage and normal concentrations of electrolyzed water in hospital. In our study, the effects of different concentrations of electrolyzed water named Envirolyte® (Industries International Ltd., Estonia) on two gram positive, four gram negative standard strains and clinical isolates of four gram negative, two gram positive, one spore-forming bacillus and Myroides spp strains that lead to hospital infections were researched. The effects of different concentrations and different contact times of Envirolyte® electrolyzed water on cited strains were researched through method of qualitative suspension tests. Petri dishes fo bacteria have been incubated at 37°C 48 hours. Bactericidal disinfectant was interpreted to be effective at the end of the period due to the lack of growth. Solutions to which disinfectant were not added were prepared with an eye to control reproduction and controlcultures were made by using neutralizing agents. 1/1, 1/2, and 1/10 concentrations of Envirolyte® electrolyzed water were found to be effective on the bacteria that lead to hospital infections used during all test times. As a conclusion, based upon the results we acquired, it was observed that Envirolyte® electrolyzed water of 100% concentration would be convenient to be used for disinfection when diluted to a usage concentration of 1/10.
Keywords: Electrolyzed water, disinfectant, bacteria

Food Science and Biotechnology 24.3 (2015): 1011-1016

Application of slightly acidic electrolyzed water and ultrasound for microbial decontamination of kashk

Application of slightly acidic electrolyzed water (SAEW) in combination with ultrasound for decontamination of kashk was investigated. SAEW had a pH of 5.3-5.5, an oxidation reduction potential of 545-600 mV, and an available chlorine concentration of 20-22 mg/L. Kashk is a dairy product with a unique aroma and a high nutritive value produced in Iran. A 2/1 SAEW/kashk ratio showed 1.42, 1.13, 1.24, and 1.37 log CFU/mL microbial reductions in Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Aspergillus fumigatus, respectively, at room temperature. A combination of SAEW treatment with ultrasound (SAEW+ultrasound) resulted in 1.87, 1.67, 1.71, and 1.91 log CFU/mL reductions in S. aureus, B. cereus, E. coli, and A. fumigatus, respectively. The developed hurdle approach can be a useful tool for sanitization of kashk and similar products. Application of SAEW+ultrasound in dairy microbial decontamination is first reported herein.

Food Control 47 (2015): 277-284

Combined effects of slightly acidic electrolyzed water and fumaric acid on the reduction of foodborne pathogens and shelf life extension of fresh pork

This study evaluated the efficacy of the individual treatments (slightly acidic electrolyzed water [SAcEW] or fumaric acid [FA]) and their combination to reduce Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus, and Salmonella Typhimurium in fresh pork as well as to study the shelf life and sensory quality (color, odor, and texture) of pork during storage at 4 and 10 °C. The inoculated pork samples (10 g) were dipped for 3 min in each treatment (tap water [TW], SAcEW, strong acidic electrolyzed water [StAEW], 0.5% FA, or SAcEW + 0.5% FA) with or without mild heat (40 °C). Decontamination of fresh pork with SAcEW +0.5% FA at 40 °C for 3 min showed greater bactericidal effect compared to other treatments, which significantly (P < 0.05) reduced E. coli O157:H7, L. monocytogenes, S. aureus, and S. Typhimurium by 2.59, 2.69, 2.38, and 2.99 log CFU/g, respectively. This combined treatment significantly (P < 0.05) yielded in a longer lag time of naturally occurring bacteria (TBC) on pork stored at 4 °C. This combined treatment also prolonged the shelf life of pork up to 6 days and 4–5 days when stored at 4 °C and 10 °C, respectively, compared to those of the untreated pork. The results suggest that the combined treatment of SAcEW + 0.5% FA has potential as a novel method to enhance the microbial safety and quality of fresh pork.

Annals of Clinical Microbiology and Antimicrobials 13.1 (2014): 29

In vitro antimicrobial activity of Medilox® super-oxidized water

Aim

Super-oxidized water is one of the broad spectrum disinfectants, which was introduced recently. There are many researches to find reliable chemicals which are effective, inexpensive, easy to obtain and use, and effective for disinfection of microorganisms leading hospital infections. Antimicrobial activity of super-oxidized water is promising. The aim of this study was to investigate the in-vitro antimicrobial activity of different concentrations of Medilox® super-oxidized water that is approved by the Food and Drug Administration (FDA) as high level disinfectant.
Material and methods

In this study, super-oxidized water obtained from Medilox® [Soosan E & C, Korea] device, which had been already installed in our hospital, was used. Antimicrobial activities of different concentrations of super-oxidized water (1/1, 1/2, 1/5, 1/10, 1/20, 1/50, 1/100) at different exposure times (1, 2, 5, 10, 30 min) against six ATCC strains, eight antibiotic resistant bacteria, yeasts and molds were evaluated using qualitative suspension test. Dey-Engley Neutralizing Broth [Sigma-Aldrich, USA] was used as neutralizing agent.
Results

Medilox® was found to be effective against all standard strains (Acinetobacter baumannii 19606, Escherichia coli 25922, Enterococcus faecalis 29212, Klebsiella pneumoniae 254988, Pseudomonas aeruginosa 27853, Staphylococcus aureus 29213), all clinical isolates (Acinetobacter baumannii, Escherichia coli, vancomycin-resistant Enterococcus faecium, Klebsiella pneumoniae, Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, Bacillus subtilis, Myroides spp.), and all yeastsat 1/1 dilution in ≥ 1 minute. It was found to be effective on Aspergillus flavus at 1/1 dilution in ≥ 2 minutes and on certain molds in ≥ 5 minutes.

Food Science and Technology Research 20.1 (2014): 93-100

Efficacy of Slightly Acidic Electrolyzed Water for Reduction of Foodborne Pathogens and Natural Microflora on Shell Eggs

The efficacy of slightly acidic electrolyzed water (SAEW) to inactivate foodborne pathogens and indigenous microbiota on shell eggs was evaluated and compared to chlorine dioxide (CD), acidic electrolyzed water (AEW) and NaClO solution. The eggs were artificially inoculated with S. enteritidis, E. coli O157:H7 and S. aureus and sprayed or immersed with SAEW, alkaline electrolyzed water (AlEW) followed by SAEW (AlEW+SAEW), CD, AEW and NaClO solution, respectively. The effect of SAEW on the natural microbiota of shell eggs was also determined. Spraying shell eggs with SAEW, CD and NaClO solution at an ACC of 60 mg/L had no significant bactericidal difference for foodborne pathogens and indigenous microbiota on shell eggs, and the difference of disinfection effect between SAEW and AEW was not significant, whereas the bactericidal activity of SAEW for E. coli O157:H7, S. aureus, total aerobic bacteria and moulds and yeasts was significantly higher than that of CD and NaClO solution at ACCs of 80 or 100 mg/L. SAEW was found to be more effective when used in conjunction with AlEW, and higher reductions were obtained with the immersion treatment. Results indicate that the disinfectant efficiency of SAEW is equivalent to or higher than that of chlorine dioxide and NaClO solution and therefore SAEW shows the potential to be used for sanitization of egg shells as an environmentally friendly disinfection agent.

Infection Control & Hospital Epidemiology 35.12 (2014): 1505-1510

Evaluating use of neutral electrolysed water for cleaning near-patient surfaces

Objective:This study aimed to monitor the microbiological effect of cleaning near-patient sites over a 48 hour period with a novel disinfectant, electrolysed water.Setting:One acute care of the elderly ward in a district general hospital in Scotland. Methods: Lockers, left and right cot-sides and overbed tables in 30 bed s paces were screenedfor 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 MRSAfor each site. The study was repeated three times at monthly intervals 3Results: There was an early and significant reduction in average ACC (360 sampled sites) from a pre-clean level of 4.3 to 1.65 cfu/cm2 at one hour after disinfectant cleaning(p< 0.0001). Average counts then increased to 3.53 cfu/cm2 a t 24 hours and 3.68 cfu/cm2 at 48 hours. Total MSSA/MRSA ( 34 isolates) declined by 71% at four hours after cleaning, but then increased to 155% ( 53 isolates) pre-clean levels at 24 hours.

The University of Georgia Cooperative Extension

Preventing Salmonella Colonization of ChickensElectrostatic Application of Electrolyzed Oxidative Acidic Water

Salmonella spp. may be found in the nest box of breeder chickens, cold egg-storage rooms at the farm, on the hatchery truck, or in the hatchery environment (5). These bacteria may then be spread to fertilized hatching eggs on the shell or, in some cases, may penetrate the shell and reside just be-neath the surface of the eggshell.Research has demonstrated that contamination of raw poultry products with Salmonella spp. may be attributable to cross-contamination in the hatchery from Salmonella infected eggs or surfaces to uninfect-ed baby chicks during the hatching process. Cox et al. (6 and 7) reported that broiler and breeder hatch-eries were highly contaminated with Salmonella spp. Within the broiler hatchery, 71 percent of eggshell fragments, 80 percent of chick conveyor belts swabs, and 74 percent of pad samples placed under newly hatched chicks contained Salmonella spp. (6).Cason et al. (4) reported that, although fertile hatch-ing eggs were contaminated with high levels of Salmonella typhimurium, they were still able to hatch. The authors stated that paratyphoid salmonellae do not cause adverse health affects to the develop-ing and hatching chick. During the hatching pro-cess, Salmonella spp. is readily spread throughout the hatching cabinet due to rapid air movement by circulation fans. When eggs were inoculated with a marker strain of Salmonella during hatching, greater than 80 percent of the chicks in the trays above and below the inoculated eggs were contaminated (4). In an earlier study, Cason et al. (3) demonstrated that salmonellae on the exterior of eggs or in eggshell membranes could be transmitted to baby chicks dur-ing pipping

PloS one 8.2 (2013): e55118

Direct Electric Current Treatment under PhysiologicSaline Conditions KillsStaphylococcus epidermidisBiofilms via Electrolytic Generation of Hypochlorous Acid

The purpose of this study was to investigate the mechanism by which a direct electrical current reduced the viability ofStaphylococcus epidermidisbiofilms in conjunction with ciprofloxacin at physiologic saline conditions meant to approximatethose in an infected artificial joint. Biofilms grown in CDC biofilm reactors were exposed to current for 24 hours in 1/10thstrength tryptic soy broth containing 9 g/L total NaCl. Dose-dependent log reductions up to 6.7 log10CFU/cm2wereobserved with the application of direct current at all four levels (0.7 to 1.8 mA/cm2) both in the presence and absence ofciprofloxacin. There were no significant differences in log reductions for wells with ciprofloxacin compared to those withoutat the same current levels. When current exposures were repeated without biofilm or organics in the medium, significantgeneration of free chlorine was measured. Free chlorine doses equivalent to the 24 hour endpoint concentration for eachcurrent level were shown to mimic killing achieved by current application. Current exposure (1.8 mA/cm2) in mediumlacking chloride and amended with sulfate, nitrate, or phosphate as alternative electrolytes produced diminished kills of 3, 2,and 0 log reduction, respectively. Direct current also killedPseudomonas aeruginosabiofilms when NaCl was present.Together these results indicate that electrolysis reactions generating hypochlorous acid from chloride are likely a maincontributor to the efficacy of direct current application. A physiologically relevant NaCl concentration is thus a criticalparameter in experimental design if direct current is to be investigated forin vivomedical applications.

Canadian Journal of Microbiology 58.4 (2012): 448-454

Efficacy of acidic and basic electrolyzed water in eradicating Staphylococcus aureus biofilm

Staphylococcus aureus is a major pathogen. It can form biofilm on the surfaces of medical devices and food equipment, which makes it more difficult to eradicate. To develop a novel method to eradicate S. aureus biofilm, the effects of electrolyzed water on removing and killing S. aureus biofilm were investigated in this study. By using a biofilm biomass assay with safranin staining and visualization of biofilm architecture with scanning electron microscopy, it was shown that basic electrolyzed water (BEW) could effectively remove established biofilm. The pH of electrolyzed water affected removal efficacy. Using a biofilm viability assay with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide staining, acidic electrolyzed water (AEW) efficiently killed biofilm-imbedded S. aureus. The available chlorine in AEW may be a main contributing factor for bactericidal activity. Additionally, BEW had a removal efficacy for S. aureus biofilm equivalent to 2% NaOH, and AEW had a bactericidal capability for S. aureus in biofilm equivalent to 2% HCl. These data suggested that AEW and BEW could be applied as a bactericide and removing agent for S. aureus in biofilm, respectively.

Food Science and Biotechnology 20.5 (2011): 1367-1371

Optimization of inactivation of Staphylococcus aureus by low concentration electrolyzed water using response surface methodology

The objective of this study was to investigate the combined effect of temperature (15–35°C), pH (3-9), and dipping time (1–5 min) on the inactivation of Staphylococcus aureus in broth treated with low concentration electrolyzed water (LcEW). Reductions of 1.44–7.12 log CFU/mL were observed in different combinations of the 3 factors. Also, a quadratic equation for S. aureus inactivation kinetic was developed by multiple regression analysis using response surface methodology. The predicted values were shown to be significantly in good agreement with experimental values as a result of the level of significance was p<0.0001. Besides, the developed model was validated by fitting with literature data and the results showed that the predictions had a good agreement with the observed data with a satisfied determination of coefficient (R2=0.963).

Journal of Food Protection 73.12 (2010): 2211-2216

Effect of slightly acidic electrolyzed water for inactivating Escherichia coli O157:H7 and Staphylococcus aureus analyzed by transmission electron microscopy

The use of different available chlorine concentrations (ACCs) of slightly acidic electrolyzed water (SAEW; 0.5 to 30 mg/liter), different treatment times, and different temperatures for inactivating Escherichia coli O157:H7 and Staphylococcus aureus was evaluated. The morphology of both pathogens also was analyzed with transmission electron microscopy. A 3-min treatment with SAEW (pH 6.0 to 6.5) at ACCs of 2 mg/liter for E. coli O157:H7 and 8 mg/liter for S. aureus resulted in 100% inactivation of two cultures (7.92- to 8.75-log reduction) at 25°C. The bactericidal activity of SAEW was independent of the treatment time and temperature at a higher ACC (P > 0.05). E. coli O157:H7 was much more sensitive than S. aureus to SAEW. The morphological damage to E. coli O157:H7 cells by SAEW was significantly greater than that to S. aureus cells. At an ACC as high as 30 mg/liter, E. coli O157:H7 cells were damaged, but S. aureus cells retained their structure and no cell wall damage or shrinkage was observed. SAEW with a near neutral pH may be a promising disinfectant for inactivation of foodborne pathogens

International Journal of Food Microbiology 139.3 (2010): 147-153

Effectiveness of low concentration electrolyzed water to inactivate foodborne pathogens under different environmental conditions

In vitro E.O. water studies on cell suspensions of bacteria and bacteria in biofilms have shown good results in their ability to kill food pathogens and spoilage organisms such as Listeria monocytogenes, Escherichia coli, Salmonella spp., Vibrio parahaemolyticus, and Pseudomonas spp. Ovissipour et al. 2015;Rahman et al. 2010). Research on the efficacy of E.O. water against those bacteria contaminating various food products has also shown excellent results in suppressing microbial contamination (Huang et al. 2006a;Kim and Hung 2012;Park et al. 2001;Pinto et al. 2015;Rahman et al. 2010;Shiroodi et al. 2016). …
… Ovissipour et al. 2015;Rahman et al. 2010). Research on the efficacy of E.O. water against those bacteria contaminating various food products has also shown excellent results in suppressing microbial contamination (Huang et al. 2006a;Kim and Hung 2012;Park et al. 2001;Pinto et al. 2015;Rahman et al. 2010;Shiroodi et al. 2016). …
… Secondly, alkaline electrolysed water (AlEW), also known as electrolysed reducing water (E.R water), is collected from the cathode side (Al-Haq et al. 2005 123 SAEW) (Xie et al. 2012;Zhang et al. 2015). It is also called low concentration electrolysed water (LcEW) (Rahman et al. 2010). In this paper E.O. water refers to neutralised or slightly acidic E.O. water unless otherwise stated.

Journal of Bioscience and Bioengineering 110.3 (2010): 308-313

In vitro inactivation of Escherichia coli, Staphylococcus aureus and Salmonella spp. using slightly acidic electrolyzed water

In the current study, the effectiveness of slightly acidic electrolyzed water (SAEW) on an in vitro inactivation of Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Salmonella spp. was evaluated and compared with other sanitizers. SAEW (pH 5.6, 23mg/l available chlorine concentration; ACC; and 940mV oxidation reduction potential; ORP) was generated by electrolysis of dilute solution of HCl (2%) in a chamber of a non-membrane electrolytic cell. One milliliter of bacteria suspension (ca. 10-11 log(10)CFU/ml) was mixed with 9ml of SAEW, strong acidic electrolyzed water (StAEW; ca. 50mg/l ACC), sodium hypochlorite solution (NaOCl; ca.120mg/l ACC) and distilled water (DW) as control and treated for 60s. SAEW effectively reduced the population of E. coli, S. aureus and Salmonella spp. by 5.1, 4.8, and 5.2 log(10)CFU/ml. Although, ACC of SAEW was more than 5 times lower than that of NaOCl solution, they showed no significant bactericidal difference (p>0.05). However, the bactericidal effect of StAEW was significantly higher (p<0.05) than SAEW and NaOCl solution in all cases. When tested with each individual test solution, E. coli, S. aureus and Salmonella spp. reductions were not significantly different (p>0.05). These findings indicate that SAEW with low available chlorine concentration can equally inactivate E. coli, S. aureus and Salmonella spp. as NaOCl solution and therefore SAEW shows a high potential of application in agriculture and food industry as an environmentally friendly disinfection agent.

Journal of food science 75.5 (2010): M253-M260

Studies on Disinfection Mechanism of Electrolyzed Oxidizing Water on E. coli and Staphylococcus aureus

Suspension quantitative germicidal test showed that electrolyzed oxidizing water (EO water) was an efficient and rapid disinfectant. Disinfection rates towards E. coli (available chlorine concentration ACC: 12.40 mg/L) and Staphylococcus aureus (ACC: 37.30 mg/L) could reach 100% at 1 and 3 min, respectively. Disinfection mechanism of EO water was investigated at a molecular biological level by detecting a series of biochemical indices. The results showed that the dehydrogenase activities of E. coli and S. aureus decreased rapidly, respectively, at the rates of 45.9% and 32% in the 1st minute treatment with EO water. EO water also improved the bacterial membrane permeability, causing the rise of conductivities and the rapid leakages of intracellular DNA, K+, and proteins in 1 min. The leakages of DNA and K+ tended to slow down after about 1 min while those of proteins began to decrease a little after reaching the peak values. The sodium dodecyl sulfonate polyacrylamide gel electrophoresis (SDS-PAGE) showed that EO water destroyed intracellular proteins. The protein bands got fainter and even disappeared as the treatment proceeded. EO water’s effects on the bacterial ultrastructures were also verified by the transmission electronic microscopy (TEM) photos. The disinfection mechanism of EO water was composed of several comprehensive factors including the destruction of bacterial protective barriers, the increase of membrane permeability, the leakage of cellular inclusions, and the activity decrease of some key enzymes.

Food Microbiology 25.1 (2008): 36-41

Reduction of bacteria on spinach, lettuce, and surfaces in food service areas using neutral electrolyzed oxidizing water

Food safety issues and increases in food borne illnesses have promulgated the development of new sanitation methods to eliminate pathogenic organisms on foods and surfaces in food service areas. Electrolyzed oxidizing water (EO water) shows promise as an environmentally friendly broad spectrum microbial decontamination agent. EO water is generated by the passage of a dilute salt solution (∼1% NaCl) through an electrochemical cell. This electrolytic process converts chloride ions and water molecules into chlorine oxidants (Cl2, HOCl/ClO−). At a near-neutral pH (pH 6.3–6.5), the predominant chemical species is the highly biocidal hypochlorous acid species (HOCl) with the oxidation reduction potential (ORP) of the solution ranging from 800 to 900 mV. The biocidal activity of near-neutral EO water was evaluated at 25 °C using pure cultures of Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, Listeria monocytogenes, and Enterococcus faecalis. Treatment of these organisms, in pure culture, with EO water at concentrations of 20, 50, 100, and 120 ppm total residual chlorine (TRC) and 10 min of contact time resulted in 100% inactivation of all five organisms (reduction of 6.1–6.7 log10 CFU/mL). Spray treatment of surfaces in food service areas with EO water containing 278–310 ppm TRC (pH 6.38) resulted in a 79–100% reduction of microbial growth. Dip (10 min) treatment of spinach at 100 and 120 ppm TRC resulted in a 4.0–5.0 log10 CFU/mL reduction of bacterial counts for all organisms tested. Dipping (10 min) of lettuce at 100 and 120 ppm TRC reduced bacterial counts of E. coli by 0.24–0.25 log10 CFU/mL and reduced all other organisms by 2.43–3.81 log10 CFU/mL.

Letters in Applied Microbiology 40.5 (2005): 341-346

Inactivation of Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa and Staphylococcus aureus on stainless steel and glass surfaces by neutral electrolysed water

https://sfamjournals.onlinelibrary.wiley.com/doi/full/10.1111/j.1472-765X.2005.01679.xAim: To ascertain the efficacy of neutral electrolysed water (NEW) in reducing Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Listeria monocytogenes on glass and stainless steel surfaces. Its effectiveness for that purpose is compared with that of a sodium hypochlorite (NaClO) solution with similar pH, oxidation–reduction potential (ORP) and active chlorine content.

Methods and Results: First, the bactericidal activity of NEW was evaluated over pure cultures (8·5 log  CFU ml−1) of the abovementioned strains: all of them were reduced by more than 7 log CFU ml−1 within 5 min of exposure either to NEW (63 mg l−1 active chlorine) or to NaClO solution (62 mg l−1 active chlorine). Then, stainless steel and glass surfaces were inoculated with the same strains and rinsed for 1 min in either NEW, NaClO solution or deionized water (control). In the first two cases, the populations of all the strains decreased by more than 6 log CFU 50 cm−2. No significant difference (P ≤ 0·05) was found between the final populations of each strain with regard to the treatment solutions (NEW or NaClO solution) or to the type of surface.

Conclusions: NEW was revealed to be as effective as NaClO at significantly reducing the presence of pathogenic and spoilage bacteria (in this study, E. coli, L. monocytogenes, P. aeruginosa and S. aureus) on stainless steel and glass surfaces.

Journal of agricultural and Food Chemistry 50.1 (2002): 230-234

Inactivation of Staphylococcal Enterotoxin-A with an Electrolyzed Anodic Solution

Electrolyzed anodic NaCl solutions [EW(+)], prepared by the electrolysis of 0.1% NaCl, have been shown to instantly inactivate most pathogens that cause food-borne disease. Elimination of food-borne pathogens does not necessarily guarantee food safety because enterotoxins produced by pathogens may remain active. We have tested whether EW(+) can inactivate Staphylococcal enterotoxin A (SEA), one of the major enterotoxins responsible for food poisoning. Fixed quantities of SEA were mixed with increasing molar ratios of EW(+), and SEA was evaluated by reversed-phase passive latex agglutination (RPLA) test, immunoassay, native polyacrylamide gel electrophoresis (PAGE), and amino acid analysis after 30 min incubations. Exposure of 70 ng, or 2.6 pmol, of SEA in 25 μL of PBS to a 10-fold volume of EW(+), or ca. 64.6 × 103-fold molar excess of HOCl in EW(+), caused a loss of immuno-reactivity between SEA and a specific anti-SEA antibody. Native PAGE indicated that EW(+) caused fragmentation of SEA, and amino acid analysis indicated a loss in amino acid content, in particular Met, Tyr, Ile, Asn, and Asp. Staphylococcal enterotoxin-A excreted into culture broth was also inactivated by exposure to an excess molar ratio of EW(+). Thus, EW(+) may be a useful management tool to ensure food hygiene by food processing industries.

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