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In the natural environment, most microorganisms live in mixed-species biofilms, in which the metabolism and growth of organisms are different from that in single-species biofilms. Adhesive bacteria and their biofilms on the surface of food processing equipment are the sources of cross-contamination, leading to the risk for humans. Slightly acidic electrolyzed water (SAEW) has been proposed as a novel sanitizer in the food and agriculture industry. In this study, we investigated the changes in the physical properties of SAEW under different conditions and the disinfection abilities of SAEW against spore-forming and non-spore-forming pathogens. Furthermore, we examined the disinfection abilities of SAEW after 12 months of shelf life on a mixed-species biofilm of Listeria monocytogenes Scott A and Staphylococcus aureus. The results showed that SAEW at 30 and 50 ppm achieved all-kill of the spore-forming pathogen Bacillus cereus within 30 s. Changes in the ACC and pH of the produced SAEW were generally affected by the storage conditions. Both spore-forming and non-spore-forming pathogens were not detected under treatment with 50 ppm SAEW for 5 min under HDPE-closed conditions throughout the whole storage period. Moreover, 25 mg/L SAEW can inactivate L. monocytogenes Scott A and S. aureus biofilm cells in ~2.45 and 2.57 log CFU/mL in biofilms within 5-min treatment. However, the decline of the two bacteria in the mixed-species biofilm was 1.95 and 1.43 log CFU/mL, respectively. The changes in the cell membrane permeability of the mixed-species biofilm under treatment with SAEW were observed by using atomic force microscopy and confocal laser scanning microscopy. L. monocytogenes Scott A was more sensitive to SAEW in the mixed-species biofilm cells. These findings exhibited strong antibiofilm activities of SAEW in impairing biofilm cell membranes, decreasing cell density, and eliminating biofilm, which suggest that SAEW is an excellent antibacterial agent in the food processing industries. [ABSTRACT FROM AUTHOR]

Slightly acidic electrolyzed water (SAEW) has been recently proposed as a novel promising sanitizer and cleaner in the agricultural and food industries. However, several factors, including water hardness, were considered to strongly affect the physical properties and sanitization efficacy of SAEW. To study the effect of water hardness on the SAEW production, we evaluated the production properties and sanitization effect of SAEW, which was generated from water sources in 16 representatively geographical locations of South Korea. The results showed that the hardness of water sources from Kangwon-do, Jeollanam-do, and Daegu was 22–41 ppm; that from Busan, Gyeongnam-do, Gwangju Bukgu was 80–443 ppm, and that from seven other locations was 41–79 ppm. SAEW is produced from water hardness less than 50 ppm and greater than 80 ppm was beyond the accepted pH range (5.0–6.5). Notably, high-hardness water (>80 ppm) containing 5% HCl could be used to produce SAEW with accepted pH. The SAEW generated from low-hardness water with additions of 2% HCl and 2 M NaCl at 7 A showed accepted pH and higher germicidal effect. Furthermore, SAEW with the available chlorine concentration of 27–41 mg/L for 1 min was sufficient to completely inactivate non–spore-forming foodborne pathogens. Sanitization efficacy was not markedly affected by storage conditions for SAEW at 40 ppm. Our results demonstrated that the degree of water hardness is an important factor in the production of SAEW, which would provide a foundation for commercial application of SAEW. [ABSTRACT FROM AUTHOR]

Ecofriendly disinfectants are being extensively investigated for their potential sanitiser efficacy and food industry application.This study aimed to explore the inhibitory effect of slightly acidic electrolyzed water (SAEW) combined with essential oil (EO) based on surfactant monolaurin (ML) on the growth of Escherichia coli O157:H7 43894, Salmonella enteritidis ATCC 13076, Listeria monocytogenes Scott ATCC 43251, Staphylococcus aureus ATCC 13565, Candida albicans KCCM 11282. The SAEW's (ACC 5, 10 and 20 mg/L) antimicrobial activity was significantly enhanced for nanoemulsion (NE). The stability of the NE was enhanced based on sonication and the particle size, and zeta potential analysis was determined. The results revealed that the addition of ML (nonionic surfactant) and high-intensity ultrasound sonication influences the formulation of oil-in-water nanoemulsion. Higher antimicrobial activity of the essential oil and electrolyzed water in both individual and combined (nanoemulsion) effect were confirmed. The nanoemulsion appeared to amplify the antimicrobial effect of SAEW with particle size (117.3 nm) suggesting the formation of SAEW–TV complexes probably through hydrophobic interaction. The zeta potential showed the enhanced stability (−37.4 mV) of the emulsion was confirmed based on sonication. The mechanism of antimicrobial ability to disrupt cell membrane integrity was investigated based on electron microscopy (TEM) analysis and based on the molecular binding, the mode of action of epinastine, oseltamivir and 2-isopropyl -5-methylphenol (−12.47, −7.98 and −9.456 kcal/mol) binding affinity was confirmed respectively. In addition, the MTT assay was assessed to evaluate the non-cytotoxic effect of the combination of (SAEW + TR + ML) as a disinfectant. [Display omitted] • Thymus vulgaris enhances the antimicrobial activity of SAEW combined with monolaurin and its nanoemulsion efficiency. • Toxicity studies examined on cell line [Human Dermal Fibroblasts (HDF)]. • The non-allergic effect was confirmed for the nanoemulsion based on HET-CAM (Hen'segg-chorioallantoic membrane test). [ABSTRACT FROM AUTHOR]

Electrolyzed water (EW) has been proposed as a novel promising sanitizer and cleaner in recent years. It is an effective antimicrobial and antibiofilm agent that has several advantages of being on the spot, environmentally friendly, cheap, and safe for human beings. Therefore, EW has been applied widely in various fields, including agriculture, food sanitation, livestock management, medical disinfection, clinical, and other fields using antibacterial technology. Currently, EW has potential significance for high-risk settings in hospitals and other clinical facilities. The research focus has been shifted toward the application of slightly acidic EW as more effective with some supplemental chemical and physical treatment methods such as ultraviolet radiations and ultrasound. This review article summarizes the possible mechanism of action and highlights the latest research studies in antimicrobial applications. [ABSTRACT FROM AUTHOR]

This study aimed to assess microbial contamination of the processed rice product, food contact surface, and air at workplaces in the infant rice food industry. Further, the effectiveness of slightly acidic electrolyzed water (SAEW) against Cronobacter sakazakii airborne and biofilm was evaluated. C. Sakazaki was detected in the grinding steps, dry room, and dry chamber, which can live in a low-water activity environment. After steaming, pathogenic bacteria counts were found immediately in the samples collected from the dry room. Escherichia coli , Bacillus cereus , C. sakazakii could be found on contact surfaces in the dry room process, pointing out these facilities as potential sources for cross-contamination. Air movement in the closed drying room enhanced the level and spread of aerosol transmission. The total bacterial count was reduced from 94.67 to 115.33 CFU/m3 to 36.00–46.67 CFU/m3 in the dry room under SAEW aerosolization at 30 ppm. SAEW spray (30 ppm) completely eliminated C. sakazakii bacterial in the laboratory-scale clean booth. In addition, SAEW at 30 ppm effectively eradicates C. Sakazakii biofilm (54.55% reduction ratio). Scanning electron microscopy assays showed that the SAEW treatment effectively inactivated C. Sakazakii biofilm cells by disrupting the biofilm matrix and damaging the cell membrane. [Display omitted] • Indoor air is a vector of microbial contamination in the infant dry snack industry. • The airborne bacteria in the dry room was 94.67–115.33 CFU/m3. • Pathogenic bacteria could be found on the food contact surface and rice processed sample in the dry room. • Slightly acidic electrolyzed water (SAEW) spryer at 30 ppm treatment inactivated airborne bacteria and C.sakazakii. • SAEW at 30 ppm inactivated C. Sakazakii biofilm cells by disrupting the biofilm matrix and damaging the cell membrane. [ABSTRACT FROM AUTHOR]