Application of slightly acidic electrolyzed water for decontamination of stainless steel surfaces in animal transport vehicles

Effect of combined electrolyzed reduced water and slightly acidic electrolyzed water spraying on the control of Salmonella, eggshell quality, and shelf life of eggs during storage

Slightly acidic electrolyzed water (SAEW) is a safe and effective disinfectant, but its sterilizing efficiency is compromised by organic matter on the egg surface. Electrolyzed reduced water (ERW) is a harmless cleaner with a decontamination effect on a variety of surfaces and can be used to remove organic matter. This study assesses the effectiveness of a combination of ERW and SAEW in eliminating Salmonella and manure mixture from egg surfaces, as well as its impact on egg quality during storage. The results show that ERW (74.14%) was more effective than deionized water (DW, 64.69%) and SAEW (70.20%) (P < 0.05) in removing manure from egg surfaces. The damage to the cuticle of eggshell treated with ERW for 28 s was similar to that of DW (P > 0.05) and less than that of SAEW (P < 0.05). Spraying ERW for 10 s followed by SAEW for 18 s (ERW + SAEW) completely removed Salmonella from the egg surface, with no bacteria detected in the residual wash solution. Additionally, ERW + SAEW demonstrated superior preservation of egg quality during storage at 25℃ than the control and ERW single treatment (P < 0.05). Moreover, ERW + SAEW resulted in less weight loss compared to SAEW single treatment (P < 0.05). In conclusion, the sequential use of ERW and SAEW appears to be a promising approach for sterilizing eggs. It not only removes organic matter and Salmonella from the egg surface but also improves the preservation quality of the egg at 25 ℃.

Kinetics of sterilization of atomized slightly acidic electrolyzed water on tableware

The aim of this study was to elucidate the kinetics of atomization of slightly acidic electrolyzed water (SAEW) for use in sterilization of secondary contaminated tableware surfaces. The sterilization efficacy of SAEW was assessed on the basis of the change in the total number of colonies with different contamination levels (101 CFU/mL and 102 CFU/mL), atomization time (10, 20, 30, 40, and 50 s), atomizing distance (5, 10, 15, 20, 25, and 30 cm), and available chlorine concentration (ACC; 25.2, 30.2, 34.9, 40.5, 44.8, and 53.3 mg/L) as the main influencing factors. According to the relationship among flux, atomization area, and time, a kinetic model of SAEW atomization for the sterilization of tableware surfaces was established. The results indicated that the sterilization efficacy of SAEW gradually improved with decreased contamination levels (12.69 %-15.74 %), extended atomization time (13.68 %-46.58 %), and increased ACC (36.89 %-95.14 %). Based on the kinetics analysis, the change law of the kinetic model of SAEW atomization and sterilization of tableware surfaces with secondary pollution was found to be consistent with the change law of sterilization (r2 > 0.8). The results of this study provide a theoretical basis for SAEW atomization for sterilization of secondary contaminated tableware surfaces and also contributes to the improvement of technological theory of SAEW sterilization.

Inactivation of Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes on stainless steel by synergistic effects of tap water-based neutral electrolyzed water and lactic acid

Contaminated food contact surface is one of the most important transmission routes for foodborne pathogens. Stainless steel is one such food-contact surface that is widely used in food-processing environments. The present study aimed to evaluate the synergistic antimicrobial efficacy of a combination of tap water-based neutral electrolyzed water (TNEW) and lactic acid (LA) against the foodborne pathogens Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes on stainless steel. The results revealed that simultaneous treatment with TNEW (ACC of 4.60 mg/L) and 0.1% LA (TNEW-LA) for 5 min resulted in 4.99-, 4.34-, and >5.4- log CFU/cm² reductions in E. coli O157:H7, S. Typhimurium, and L. monocytogenes on stainless steel, respectively. Of these, 4.00-, 3.57-, and >4.76-log CFU/cm² reductions in E. coli O157:H7, S. Typhimurium, and L. monocytogenes, respectively were exclusively attributed to the synergistic action of the combined treatments after factoring out the reductions due to individual treatments. Furthermore, five mechanistic investigations revealed that the key mechanisms underlying the synergistic antibacterial effect of TNEW-LA were reactive oxygen species (ROS) production, cell membrane damage resulting from membrane lipid oxidation, DNA damage, and inactivation of intracellular enzymes. Overall, our findings suggest that the TNEW-LA combination treatment could be effectively used in the sanitization of food processing environments, especially the food contact surfaces, to control major pathogens and enhance food safety.

Hydrogen-Rich Water Treatment of Fresh-Cut Kiwifruit with Slightly Acidic Electrolytic Water: Influence on Antioxidant Metabolism and Cell Wall Stability

The synergistic impact of hydrogen-rich water (HRW, 394 ppb) and slightly acidic electrolyzed water (SAEW, pH of 6.25 ± 0.19) on the antioxidant metabolism of fresh-cut kiwifruit during storage was investigated (temperature: (3 ± 1) °C, humidity: 80%-85%). Compared with control group, H+S treatment increased the contents of active oxygen-scavenging enzymes (SOD, CAT, POD, and APX) and inhibited the increase of O₂^•- and H₂O₂ contents during the storage of fresh-cut kiwifruit. Meanwhile, H+S treatment could reduce the activities of the cell wall-degrading enzymes PG, PME, PL, Cx, and β-Gal, inhibit the formation of soluble pectin, delay the degradation rate of propectin, cellulose, and pseudocellulose, and maintain higher fruit hardness and chewability. The results showed that H+S treatment could enhance free radical scavenging ability and reduce the cell wall metabolism of fresh-cut kiwifruit, maintaining the good texture found in fresh-cut fruit.

Slightly acidic electrolyzed water as an alternative disinfection technique for hatching eggs

Conventional chemical disinfectants used for egg disinfection could result in toxic residue and endanger hatchability, chick quality, and pullet growth performance. Slightly acidic electrolyzed water (SAEW) is known as a novel disinfectant for egg sterilization due to its high efficiency and no residue. In this study, a comprehensive assessment of slightly acidic electrolyzed water and benzalkonium bromide solution (BBS) used in the disinfection channel was conducted to assess the microbial count, eggshell quality, and hatchability concomitantly. The results show that the sterilization efficiency of SAEW increased with an increase in available chlorine concentration (ACC), spraying volume, and sterilization duration. SAEW with an ACC of 150 mg/L and 10,000 mg/L benzalkonium bromide solution had the same sterilization rates of approximately 86.2% at a spraying volume of 0.5 mL/egg and sterilization duration of 180 s. Neither had significant effect on eggshell strength or thickness. The eggshell cuticle quality in the benzalkonium bromide group was significantly higher than the control group (no disinfection) and the 150 mg/L SAEW group. The embryo weight, relative embryo weight, hatchability, and embryonic mortality in the SAEW group had no significant differences of those in the benzalkonium bromide group. SAEW should be more popular because of its simple preparation, low cost, and no residue. Our results indicate SAEW is an alternative disinfectant for the sterilization of hatching eggs instead of conventional chemical disinfectants, such as benzalkonium bromide, and give a recommendation is using SAEW as a disinfectant with 150 mg/L ACC, 0.5 mL/egg spray volume, and disinfection for 180 s in the novel disinfection channel.

Simultaneous annihilation of microorganisms and volatile organic compounds from municipal solid waste storage rooms with slightly acidic electrolyzed water

Great deal pathogenic bacteria and malodorous gases are hidden in municipal solid waste (MSW), which poses excellent environmental sanitation risks for sanitation workers and residents, and preventive measures should be implemented. In this study, the simultaneous annihilation of microorganisms and volatile organic compounds (VOCs) with slightly acidic electrolyzed water (SAEW) was investigated in an MSW storage room of a residential community in Shanghai, China. The microbial population of airborne, surfaces and handles of waste bins, hands of sanitation workers and the main components of VOCs were measured. The results indicated that the bacterial reduction efficiencies of SAEW with an available chlorine concentration (ACC) of 50-100 mg/L on surfaces and handles of waste bins and sanitation workers' hands were 22.7%-84.1%. Also, SAEW effectively reduced the average population of airborne bacteria and fungi by 358 and 378 colony-forming units (CFU)/m³ and decreased the detection rates of coliforms by 14.2%-51.9%. The concentrations of most VOCs were reduced by 21.4%-88.3% after spraying SAEW. And the accumulated values of carcinogenic and noncarcinogenic risks also tended to decrease with spraying SAEW. These findings imply that SAEW has significant application potential to control environmental sanitation risks in MSW storage rooms.

Antibacterial effect of acidic ionized water on horse wounds bacterial isolates

Background and Aim

Horse wounds can be easily infected with bacteria depending on the nature of its cause such as laceration, abrasion, or puncture as well as the nature of its environment. Various treatments are available in managing open wounds, including the usage of topical antibiotics and antiseptics. However, antibiotic resistance has been a major concern attributed with chronic wound infection. The aim of this study was to test the efficacy of ionized water at different pH against the growth of common bacteria from horse wounds.

Materials and Methods

Ten swab samples from equine infected wounds were collected and bacteria isolation and identification were performed. The antibacterial effect of the ionized water of pH 2.5, 4.5, 7.0, and 11.5 was tested on Staphylococcus aureus, Staphylococcus pseudintermedius, Staphylococcus intermedius, Escherichia coli, Pantoea agglomerans, and Klebsiella pneumoniae. The time-kill profiles of the ionized waters were determined at time 0, 2, 4, 6, and 8 h.

Results

Ionized water of pH 2.5 and 4.5 showed antibacterial activity against S. aureus, S. pseudintermedius, and S. intermedius with significant (p>0.05) reduction in colony-forming unit/mL within 2-8 h. The degree of bactericidal effect of the acidic ionized water differs between the species with S. intermedius more susceptible. However, there was no antibacterial effect at pH 2.5, 4.5, 7.0, and 11.5 on the Gram-negative bacteria tested.

Conclusion

Ionized water of pH 2.5 and 4.5 is effective in minimizing the growth of Gram-positive bacteria; thus it could be of clinical importance as an antiseptic for surface wound lavage in horses.

New Clinical Applications of Electrolyzed Water: A Review

As the situation of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is still deteriorating, there has been a huge increase in the demand and use of disinfectants. Electrolyzed water (EW), as a novel broad-spectrum disinfectant and cleaner, has been widely used for several years. EW can be produced in an electrolysis chamber which contains dilute salt and tap water. It is an effective antimicrobial and antibiofilm agent, with several advantages such as on-the-spot, cheap, environmentally friendly and safe for human beings. Therefore, EW holds potential significance for high-risk settings in hospitals and other clinical facilities. EW can also be applied for wound healing, advanced tissue care, and dental clinics. The present review article highlights the latest developments and new perspectives of EW, especially in clinical fields. Furthermore, the main action modes of antibiofilm and antimicrobial will be summarized.

A systematic review of chlorine-based surface disinfection efficacy to inform recommendations for low-resource outbreak settings

BACKGROUND

Infectious diseases can be transmitted via fomites (contaminated surfaces/objects); disinfection can interrupt this transmission route. However, disinfection guidelines for low-resource outbreak settings are inconsistent and not evidence-based.

METHODS

A systematic review of surface disinfection efficacy studies was conducted to inform low-resource outbreak guideline development. Due to variation in experimental procedures, outcomes were synthesized in a narrative summary focusing on chlorine-based disinfection against 7 pathogens with potential to produce outbreaks in low-resource settings (Mycobacterium tuberculosis, Vibrio cholerae, Salmonella spp., hepatitis A virus, rotavirus, norovirus, and Ebola virus).

RESULTS

Data were extracted from 89 laboratory studies and made available, including 20 studies on relevant pathogens used in combination with surrogate data to determine minimum target concentration × time ("CT") factors. Stainless steel (68%) and chlorine-based disinfectants (56%) were most commonly tested. No consistent trend was seen in the influence of chlorine concentration and exposure time on disinfection efficacy. Disinfectant application mode; soil load; and surface type were frequently identified as influential factors in included studies.

CONCLUSIONS

This review highlights that surface disinfection efficacy estimates are strongly influenced by each study's experimental conditions. We therefore recommend laboratory testing to be followed by field-based testing/monitoring to ensure effectiveness is achieved in situ.

Optimization of Electrolysis Parameters for Green Sanitation Chemicals Production Using Response Surface Methodology

Electrolyzed water (EW) shows great potential as a green and economical sanitation solution for the food industry. However, only limited studies have investigated the optimum electrolysis parameters and the bactericidal effect of acidic electrolyzed water (AcEW) and alkaline electrolyzed water (AlEW). Here, the Box–Behnken experimental design was used to identify the optimum parameters. The tests were conducted with different types of electrodes, electrical voltages, electrolysis times, and NaCl concentrations. There were no obvious differences observed in the physico-chemical properties of EW when different electrodes were used. However, stainless steel was chosen as it meets most of the selection criteria. The best-optimized conditions for AcEW were at 11.39 V, 0.65 wt.% NaCl, and 7.23 min, while the best-optimized conditions for AlEW were at 10.32 V, 0.6 wt.% NaCl, and 7.49 min. The performance of the optimum EW (AcEW and AlEW) compared with commercial cleaning detergents for the food industry was then evaluated. The bactericidal activity of AcEW and AlEW was examined against Escherichia coli ATCC 10536 at different temperatures (30 °C and 50 °C) for 30 s. The results show that both AcEW and AlEW have the ability to reduce the Escherichia coli to non-detectable levels (less than 2 log CFU/mL).

Application of slightly acidic electrolyzed water and ultraviolet light for Salmonella enteritidis decontamination of cell suspensions and surfaces of artificially inoculated plastic poultry transport coops and other facility surfaces

The efficiency of combination treatment of slightly acidic electrolyzed water (SAEW) and ultraviolet light (UV) for inactivation of Salmonella enteritidis (S. enteritidis) on the surface of plastic poultry coops and other facility surfaces was evaluated in the presence of organic matter. The bactericidal activities of SAEW, UV + SAEW, and composite phenol (CP) for inactivating S. enteritidis were also compared. Moreover, a model of UV + SAEW treatment of plastic transport coops with different times and available chlorine concentrations (ACC) was developed using multiple linear regression analysis. There are differences between SAEW and CP inactivation of S. enteritidis on coops, stainless steel, and glass surfaces (P < 0.05), and there are no differences between SAEW and CP on tire surfaces (P > 0.05). Disinfection of some rough material surfaces with SAEW treatment alone under feces interference on poultry farms may need a longer treatment time and/or a higher ACC than smooth surfaces. The combined treatment of UV and SAEW showed higher inactivation efficiency of S. enteritidis compared to CP and SAEW treatment alone (P < 0.05) in pure cultures or on the facility surfaces. A complete 100% inactivation of S. enteritidis on plastic poultry coop surfaces was obtained by using UV + SAEW with an ACC of 90 mg/L for more than 70 s. The established model had a good fit that was quantified by the determination coefficient R² (0.93) and a lack of fit test (P > 0.05). The bactericidal efficiency of UV + SAEW increased with greater ACC and increasing time. The findings of this study indicate that the combination treatment of UV and SAEW may be a promising disinfection method and could be used instead of SAEW alone, especially on rough materials in the presence of organic matter on poultry farms.