Slightly Acidic Electrolyzed Water Treatment Research Articles

Structural insights on anti-biofilm mechanism of heated slightly acidic electrolyzed water technology against multi-resistant Staphylococcus aureus biofilm on food contact surface

Slightly acidic electrolyzed water (SAEW) has proven to be an efficient and novel sanitizer in food and agriculture field. This study assessed the efficacy of SAEW (30 mg/L) at 40 °C on the inactivation of foodborne pathogens and detachment of multi-resistant Staphylococcus aureus (MRSA) biofilm. Furthermore, the underlying mechanism of MRSA biofilm under heated SAEW at 40 °C treatment on metabolic profiles was investigated. The results showed that the heated SAEW at 40 °C significantly effectively against foodborne pathogens of 1.96–7.56 (lg (CFU/g)) reduction in pork, chicken, spinach, and lettuce. The heated SAEW at 40 °C treatment significantly reduced MRSA biofilm cells by 2.41 (lg (CFU/cm2)). The synergistic effect of SAEW treatment showed intense anti-biofilm activity in decreasing cell density and impairing biofilm cell membranes. Global metabolic response of MRSA biofilms, treated by SAEW at 40 °C, revealed the alterations of intracellular metabolites, including amino acids, organic acid, fatty acid, and lipid. Moreover, signaling pathways involved in amino acid metabolism, energy metabolism, nucleotide synthesis, carbohydrate metabolites, and lipid biosynthesis were functionally disrupted by the SAEW at 40 °C treatment. As per our knowledge, this is the first research to uncover the potential mechanism of heated SAEW treatment against MRSA biofilm on food contact surface.

Stable chlorine dioxide combined with slightly acidic electrolyzed water as preservation strategies in large yellow croaker (Pseudosciaena crocea) during cold storage: Effects on microbiological, physicochemical, and sensorial qualities

AbstractUsing stable chlorine dioxide (ClO2) combined with slightly acidic electrolyzed water (SAEW), the quality variations of cold‐stored large yellow croaker (Pseudosciaena crocea) were studied. The results of microbial indicators demonstrated that ClO2 and SAEW treatment inhibited microbial growth. Moreover, ClO2 + SAEW treatment had lower values of pH, malondialdehyde content, total volatile basic nitrogen, and higher water‐holding capacity than those in other groups. From the results of free amino acids and trimethylamine, ClO2 + SAEW treatment could delay the breakdown of umami amino acids and the accumulation of bitter amino acids in large yellow croaker. According to the results of microbial indexes and K‐value, compared with sterile distilled water treatment, the shelf life of large yellow croaker with ClO2 + SAEW treatment was extended for an additional 4 days. Therefore, ClO2 + SAEW treatment is a potential method to preserve the flavor and quality of large yellow croaker during cold storage.

Application of Slightly Acidic Electrolyzed Water as a Potential Sanitizer in the Food Industry

The food industry has extensively explored postharvest microbial control, seeking viable technologies to ensure food safety. Although numerous chlorine-based commercial sanitizers serve this purpose, many are plagued by constraints such as instability and diminished disinfectant efficacy. These issues arise from exposure to organic matter in wash water, light, or air. As an innovative and promising alternative, slightly acidic electrolyzed water (SAEW) has emerged, captivating attention for its robust sterilization potential and eco-friendliness in agricultural and food sectors. SAEW generated via electrolysis of a diluted hydrochloric acid (HCl) solution with concentrations ranging from 2 to 6% or aqueous solution of sodium chloride (NaCl) in a nonmembrane electrolytic chamber is reported to possess equivalent antimicrobial properties as strong acidic electrolyzed water (StAEW). In contrast to traditional chlorine sanitizers, SAEW leaves less chlorine residue on sanitized foods such fresh-cut fruit and vegetables, meat, poultry, and aquatic products due to its low available chlorine concentration (ACC). Its near neutral pH of 5 to 6.5 not only renders it environmentally benign but also mitigates the production of chlorine gas, a contrast to low pH conditions seen in StAEW generation. The bactericidal effect of SAEW against various strains of foodborne pathogens is widely believed and accepted to be due to the combined action of high oxidation-reduction-potential (ORP) reactions and undissociated hypochlorite/hypochlorous acid (HOCl). Consequently, a burgeoning interest surrounds the potential of SAEW for sanitation in the food industry, offering an alternative to address shortcomings in sodium hypochlorite solutions and even StAEW. It has been hypothesized from a number of studies that SAEW treatment can increase the quality and nutritional value of harvested fruits, which in turn may enhance their ability to be stored. Therefore, SAEW is not only a promising sanitizer in the food industry but also has the potential to be an efficient strategy for encouraging the accumulation of bioactive chemicals in plants, especially if it is used extensively. This review encapsulates the latest insights concerning SAEW, encompassing its antimicrobial effectiveness, sanitization mechanism, advantages vis-à-vis other sanitizers, and plausible applications across the food industry.

Ultrasound synergistic slightly acidic electrolyzed water treatment of grapes: Impacts on microbial loads, wettability, and postharvest storage quality

Microbial contamination is the principal factor in the deterioration of postharvest storage quality in grapes. To mitigate this issue, we explored a synergistic treatment which combines ultrasound (US) and slightly acidic electrolyzed water (SAEW), and rigorously compared with conventional water cleaning (CW), exclusive US treatment, and standalone SAEW treatment. The US + SAEW treatment proved to be markedly superior in reducing total bacterial, mold & yeast counts on grapes. Specifically, it achieved reductions of 2.23 log CFU/g and 2.76 log CFU/g, respectively, exceeding the efficiencies of SAEW (0.78, 0.75), US (0.58, 0.65), and CW (0.24, 0.46). The efficacy of this synergistic treatment is attributed to the ultrasound removal of the wax layer on grape skins, which transitions the skin from hydrophobic to hydrophilic. This alteration increases the contact area between the grape surface and SAEW, thereby enhancing the antimicrobial efficacy of SAEW. From a physicochemical quality standpoint, the US + SAEW treatment exhibited multiple advantages. It not only minimized weight loss, color deviations, polyphenol oxidase activity and malondialdehyde synthesis in comparison to CW-treated samples but also preserved firmness, sugar-acid ratio and the activities of key enzymes including phenylalanine ammonia-lyase, superoxide dismutase and catalase, and thus maintaining high levels of total phenolics, total ascorbic acid, total anthocyanins, and antioxidants. Consequently, US + SAEW treatment put off the times of decay onset in grapes by 12 days, outperforming both SAEW (8) and US (4) in comparison to CW. These results highlight the potential of US + SAEW as an effective strategy for maintaining grape quality during their postharvest storage period.

Stable chlorine dioxide combined with slightly acidic electrolyzed water: an effective way to delay protein deterioration of refrigerated large yellow croaker (Pseudosciaena crocea)

SummaryFish is susceptible to spoilage for enzymatic and microbial activities during storage, proteolysis of MPs by endogenous proteases played a crucial influence in the early postmortem decomposition of myosin. This study aimed to investigate the impact of stable chlorine dioxide (ClO2) combined with slightly acidic electrolyzed water (SAEW) on myofibrillar proteins (MPs) and endogenous proteases alterations in large yellow croaker (Pseudosciaena crocea) during cold storage. The results of Fourier‐transform infrared spectroscopy (FT‐IR) and intrinsic fluorescence intensity (IFI) showed that the ClO2 + SAEW treatment kept the structural stability of protein in fillets during cold storage. Moreover, ClO2 + SAEW treatment dramatically inhibited protein degradation and oxidation. The results of light microscopy further confirmed the results. Meanwhile, there was a tendency to first increase and then decrease on the activities of calpain and cathepsin B, L. According to the correlation analysis and principal component analysis, the activities of endogenous proteases (cathepsin B, D, L, and calpain) were significant (P < 0.01) positively correlated to myofibrillar fragmentation index and trichloroacetic acid‐soluble peptide, and were significant (P < 0.01) negative correlated with the contents of total sulfhydryl and Ca2+‐ATPase. The endogenous proteases activities and protein deterioration were strongly associated. Therefore, endogenous protease was affected by ClO2 and SAEW, which delayed protein degradation in large yellow croaker, especially ClO2 combined with SAEW treatment.

Effect of Slightly Acidic Electrolyzed Water on Growth, Diarrhea and Intestinal Bacteria of Newly Weaned Piglets.

As an environmentally-friendly agent, slightly acidic electrolyzed water (SAEW) was introduced in drinking water of newly weaned piglets for diarrhea prevention. In total, 72 piglets were employed and 3% SAEW was added into the normal temperature and warm (30 °C) tap water, respectively, for this 33-day feeding experiment. It was found that the total bacteria and coliforms in the drinking water were reduced by 70% and 100%, respectively, with the addition of 3% SAEW. After SAEW treatment, the average daily water and feed intakes of piglets were increased during the first 16 days, and the diarrhea rate was reduced by 100%, with not one case of diarrhea recorded at the end of the experiment. The microbiome results demonstrated that SAEW decreased the diversity of caecum bacteria with normal tap water supplied, and increased the richness of the caecum bacteria with warm tap water supplied. SAEW also increased the abundance of potentially beneficial genera Sutterella and Ruminococcaceae_UCG-005 and reduced the abundance of pathogenic Faecalibacterium. Moreover, twelve metabolic functions belonging to the cluster of metabolism and organismal functions, including digestion and the endocrine and excretory systems, were greatly enhanced. Correlation analysis indicated that the influence of intestinal pathogens on water and feed intakes and the diarrhea of piglets were decreased by SAEW. The results suggest that SAEW can be used as an antibiotic substitute to prevent diarrhea in newly weaned piglets.

Efficient aluminum removal and microorganism inhibition in ready-to-eat jellyfish by slightly acidic electrolyzed water

Ready-to-eat jellyfish production is restricted by the high aluminum residue and unable use of thermal sterilization. In this study, the combined dealumination and sterilization by slightly acidic electrolyzed water (SAEW) were used to produce ready-to-eat jellyfish. The optimal aluminum removal amount reaching 120.17 mg/kg was obtained after response surface analysis. Structure observation through optical microscope after Masson staining and scanning electron microscope showed that the microstructure of jellyfish was not destroyed after SAEW treatment. The increase of total plate count (TPC) and pH value during storage was significantly inhibited by SAEW, while the other properties did not changed significantly. Staphylococcus, especially Staphylococcus epidermidis was dominant in the ready-to-eat jellyfish and many spoilage bacteria were inhibited by SAEW. The correlation network maps showed that Pseudomonas and Shewanella contributed most to the increase of TPC and pH value in the control group, while the correlated microbial genera mainly changed to Acinetobacter, Cutibacterium, and Pseudomonas after SAEW treatment, resulting in the decrease of hardness and chewiness of ready-to-eat jellyfish during storage. The inhibited Pseudomonas contributed most to the decrease of TPC and pH value after SAEW treatment. This study provides a novel technology of dealumination and sterilization for ready-to-eat jellyfish.

Biocontrol and anti-biofilm potential of aerosols sprayed slightly acidic electrolyzed water against Cronobacter sakazakii in infant food industry

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.

Evaluating the effects of plasma-activated slightly acidic electrolyzed water on bacterial inactivation and quality attributes of Atlantic salmon fillets

In this study, an intervention non-thermal processing technology plasma-activated slightly acidic electrolyzed water (PASW) was developed to better preserve salmon fillets. Compared to the plasma-activated water (PAW) and slightly acidic electrolyzed water (SAEW), PASW treatment was found to be more effective in inactivating microorganisms. After PAW, SAEW, or PASW treatment for 120 s, the population of Shewanella putrefaciens (S. putrefaciens) was reduced by 2.04, 2.62 and 2.08 Log CFU/mL (P < 0.05) using plate counts, respectively. The test for the leakage of nucleic acids and protein in intracellular contents confirmed that PASW caused serious damage to the microbial cell structural integrity compared to that alone PAW or SAEW. Meanwhile, scanning electron microscopic observations also showed that PASW caused apparent bacterial structural changes. Besides, the PASW treatment did not alter color and textural properties of salmon fillets, and restrained lipid oxidation as compared to the control and SAEW treatments. In all, this study compared the bacterial inactivation mechanisms for PAW, SAEW, and PASW, and suggested that PASW was effective in inactivating S. putrefaciens of salmon fillets. Industrial relevancePlasma-activated slightly acidic electrolyzed water, an emerging technology in food processing, can be a potential green technology for the processing of aquatic food products. PASW treatment had higher disinfection efficacy than that of SAEW or PAW treatment alone, and no adverse effect on the quality of Atlantic salmon fillets. These results boost knowledge in the food preservation field, as well as the application of non-thermal processing in the food industry.

Effect of Slightly Acidic Electrolyzed Water Immersion at Different Frequencies on Quality of Raw Chicken Legs.

Slightly acidic electrolyzed water (SAEW) is used as a disinfectant for raw chicken meat. Because its volume for a single immersion exceeds 10 times the weight of meat, a large amount of wastewater is generated. Importantly, a higher frequency of immersion is believed to reduce microbial contamination. The objective of this study was to investigate the effect of SAEW immersion at different frequencies on the disinfection and quality of raw chicken legs, thereby possibly limiting the usage of SAEW. Immersion for 1, 3, and 5 times, with a 7:1 SAEW:meat ratio, and duration of 15 min was tested. Meat quality was evaluated based on total aerobic bacteria, Enterobactericeae, total volatile basic nitrogen, thiobarbituric acid reactive substances, and color. A higher immersion frequency lowered the numbers of total aerobic bacteria and Enterobacteriaceae. Moreover, two immersions with a SAEW:meat ratio of 4:1 and a total immersion time of 6 min reduced the bacterial load as effectively as a single 15-min immersion with a SAEW:meat ratio of 7:1. Higher frequencies of SAEW immersion also resulted in lower total volatile basic nitrogen and lipid oxidation after 0 or 3 days of storage. They did, however, magnify the change in color, resulting in brighter meat. Overall, SAEW treatments with two to five immersions can improve the quality of raw chicken legs and reduce wastewater generation.

Efficacy of Slightly Acidic Electrolyzed Water (SAEW) Comparing to Chlorine on Inactivation of Legionella Pneumophila Isolated from Drinking Water Tanks

Legionella is an opportunistic waterborne pathogen which is transmitted to humans via inhalation of contaminated water droplets. In addition, Legionella pneumophila is considered ubiquitous bacterium which inherently resistant to chlorine in tap water. On the other side, recent researches revealed that SAEW is considered a novel sanitizer against a broad spectrum of bacteria and possesses nonselective antimicrobial properties. A total of 300 drinking water samples were collected from water tanks (100 samples from hotels, 100 samples from plants and 100 samples from residential units) at Alexandria and Cairo governments from January till July 2023. Results revealed that the incidence of Legionella species in drinking water samples from hotels, plants and residential units water tanks were 0 % (0/100) , 3 % (3/100) and 1% (1/100), respectively. Two isolates from plants water tanks were identified as Legionella pneumophila by RT PCR. The efficacy of slightly acidic electrolyzed water (SAEW) was assessed comparing to chlorine on inactivation and biofilm adherence strength of Legionella pneumophila isolates. The obtained results showed that SAEW was more effective on inactivation of the two Legionella pneumophila isolates than chlorine within shorter treatment duration, where 100 % inactivation of Legionella pneumophila achieved after 3 hrs and 48 hrs from SAEW and chlorine treatment, respectively. In addition, SAEW showed significant effect on the biofilm adherence strength of the two Legionella pneumophila isolates. This study underlines the highly antimicrobial effect of SAEW on inactivation of Legionella within short duration without any undesirable residual agents in water which may cause further water pollution.

Slightly acidic electrolyzed water treatment improves the quality and storage properties of carambola fruit

This study aimed to explore the impacts of slightly acidic electrolyzed water (SAEW) treatment on the physiology, quality, and storage properties of postharvest carambola. The carambolas were immersed in SAEW with a pH value of 6.0, ORP of 1340 mV and ACC of 80 mg/L. Results demonstrated that SAEW could significantly reduce the respiration rate, inhibit the increase in cell membrane permeability, and delay apparent color change. Relatively higher contents of bioactive compounds and nutritional components, such as flavonoids, polyphenols, reducing sugars, sucrose, vitamin C, total soluble sugar, and total soluble solid, as well as higher titratable acidity were maintained in SAEW-treated carambola. In addition, SAEW-treated carambola exhibited a higher commercial acceptability rate and a higher firmness, but lower weight loss and peel browning index than control fruits. Our results indicated that SAEW treatment achieved high fruit quality and nutritional values, potentially contributing to improve storage properties of harvested carambola.

Nutrient Composition of Germinated Foxtail Millet Flour Treated with Mixed Salt Solution and Slightly Acidic Electrolyzed Water

Germination of millet can improve its consumption quality, optimize its nutritional composition, and promote the accumulation of functional components such as γ-aminobutyric acid (GABA). In the present study, foxtail millet was germinated with tap water, a mixed salt solution of 7.5 mmol/L NaCl and 15 mmol/L CaCl2, and slightly acidic electrolyzed water (SAEW) with three available chlorine concentrations (ACCs; 10.92, 20.25, and 30.35 mg/L). The effects of the salt solution and SAEW on the germination of foxtail millet and the GABA, crude protein, and amino acid composition of the germinated millet flour were analyzed. The results showed that the salt solution and SAEW treatments promoted the growth of millet sprouts, contributed to the accumulation of GABA in germinated millet flour, and optimized the protein and amino acid composition. The GABA content of germinated foxtail millet flour treated with salt solution for 60 h (336.52 mg/100 g) was 29.5 times higher than that of ungerminated millet flour. In conclusion, the highest GABA content and amino acid scores of germinated millet flour obtained by germination treatment with salt solution at 25 °C and 86% humidity for 60 h were more acceptable for human nutritional requirements.

Effects of Slightly Acidic Electrolyzed Water on the Quality of Fresh-Cut Apple.

To investigate the effects of a slightly acidic electrolyzed water (SAEW) treatment on the quality of fresh-cut apples during storage, this research used a Box-Behnken design to determine the optimal SAEW treatment conditions. Then, the fresh-cut apple was treated under the optimal condition and subjected to a 13-d storage experiment at 4 °C. For fresh-cut apple treated under the optimal SAEW treatment conditions, the total number of surface colonies was reduced by 2.82 logarithms compared to the control group and the sensory score was 8.73. For the treated fresh-cut apple during storage, the quality of the treated group was significantly greater than the non-treatment group. Thus, the SAEW treatment not only effectively controlled the number of microbes on fresh-cut apple, but also slowed quality deterioration during storage.

Effects of Wheat Tempering with Slightly Acidic Electrolyzed Water on the Microbiota and Flour Characteristics.

Slightly acidic electrolyzed water (SAEW) was prepared and used as wheat tempering water. This study explored the impacts of tempering with SAEW on microbial load and diversity and quality properties of wheat flour. As SAEW volume ratio increased, the residual level of total plate counts (TPC) and mould/yeast counts (MYC) decreased dramatically (p &lt; 0.05). Based on genomics analysis, bacterial 16S rRNA gene and fungal ITS1 gene region were performed to characterize the changes in microbial communities' composition and diversity in response to SAEW treatment. SAEW optimal volume ratio (6.5:10, v/v) of SAEW with distilled water influenced wheat microbiome composition, with a higher microbial diversity and abundance discovered on the control grains. Bacteroidetes of predominant bacterial phylum and Ascomycota of the most abundant fungal phylum were reduced after SAEW optimal volume ratio tempering. The flour yield is higher and ash content is lower than the control samples. Falling number and "b*" in terms of colour markedly increased. DSC (Differential Scanning Calorimetry) test showed that To (onset temperature), Tp (peak temperature), and Tc (conclusion temperature) were significantly decreased in thermal characteristics of flour. Gluten content, protein content, ΔH and pasting properties tests showed no significant change. It can be concluded that SAEW should be applied on wheat tempering for producing clean wheat flour. ANOVA and Tukey's honestly significant difference (HSD) test were used for the analysis of variance and differences between the experimental and control groups, with p &lt; 0.05.

Impact of slightly acidic electrolyzed water in combination with ultrasound and mild heat on safety and quality of fresh cut cauliflower

Slightly acidic electrolyzed water (SAEW) has recently gained a lot of interest as a chlorine sanitizer which provides higher decontamination effect with minimum available chlorine. Nevertheless, microbial reductions via only SAEW treatment are not sufficient to assure safety. Hence, it is required to enhance the disinfection efficacy by combining with other compatible techniques. In the present study, SAEW with a pH of 5.5–5.6, available chlorine content (AAC) of 20–22 mg/L, oxidation-reduction potential of 900–950 mV was applied on fresh-cut cauliflower to determine the microbicidal activity. SAEW was also applied in combination with ultrasound treatment (US) and moderate heat (45 °C) to enhance the decontamination efficacy of SAEW. The impacts of individual (SAEW) and combined treatments like (SAEW + US), (SAEW + US + mild heat 45 °C) on microbial population, physicochemical, and antioxidant properties of cauliflower were evaluated. The combined treatment of SAEW, US and mild heat showed better effectiveness on microbial decontamination compared to SAEW treatment alone, and SAEW with US (SAEW + US) treatment but significantly reduced the antioxidant and phytochemical properties of fresh cauliflower. However, SAEW with US treatment (SAEW + US) preserved the bioactive compounds and antioxidant activity with significant reduction of microbial load. The present study revealed that combination of SAEW with US treatment can be a promising decontamination technique to improve postharvest quality and safety of fresh produce.

Ultrasound assisted slightly acidic electrolyzed water treatment on the protein structure stability of vacuum‐packaged sea bass (Lateolabrax japonicas) during refrigerated storage

AbstractThis study evaluated the synergistic effects of ultrasound (US) and slightly acidic electrolyzed water (SAEW) treatment on the myofibril protein structure of vacuum‐packed sea bass (Lateolabrax japonicas) during refrigerated storage. Fresh sea bass fillets were treated with US, SAEW, US combined with SAEW treatment (US + SAEW), and sterile water (Control) for 10 min, respectively. Different indexes, such as hardness, myofibril fragmentation index (MFI), water activity (aw), and surface hydrophobicity, which also combined with protein characteristic (intrinsic fluorescence intensity) were analyzed. The results showed that the US treatment increased the MFI and surface hydrophobicity of sea bass. Compared with the control group, the bactericidal effect of US + SAEW treatment made the sample better water holding capacity, water activity, and higher fluorescence intensity. Differential scanning calorimetry spectrum results showed that samples treated by US had loose myofibrillary structure, which was convenient for SAEW to act more effectively. US + SAEW treatment retarded the degradation of protein. These results provided evidence that US + SAEW treatment could maintain the quality of fish.

The increase of antioxidant capacity of broccoli sprouts subject to slightly acidic electrolyzed water

The growing recognition of a healthy lifestyle framework has promoted the development of novel functional foods or superfoods with abundant nutrients and health-promoting properties. Therefore, the influence of slightly acidic electrolyzed water (SAEW) as an elicitor on broccoli sprouts was investigated. The increase of electrolyte leakage percentage, thiobarbituric acid reactive substances levels and proline concentration indicated that the defense system of broccoli sprouts had responded to stress caused by SAEW. Furthermore, the antioxidant enzymes and secondary metabolites, phenolic compounds, were evaluated and revealed the enhancement of antioxidant enzymes (superoxide dismutase, peroxidases, catalase, and ascorbate peroxidase) activities and phenolic compounds content in broccoli sprouts with SAEW treatment. The major groups of phenolic composition in broccoli sprouts were phenolic acids and flavonoids. The Folin-Ciocalteu index and antioxidant activity assay also proved the enhancement of antioxidant capacity of broccoli sprouts with SAEW treatment. Results from this study indicated that SAEW treatment could increase the antioxidant ability of broccoli sprouts.

Efficacy of combination of slightly acidic electrolyzed water and ultrasound for inactivation of Vibrio parahaemolyticus in vitro and in sliced tilapia

The aim of this study was to investigate the effect of slightly acidic electrolyzed water (SAEW) and ultrasound (US) combination on the inactivation of Vibrio parahaemolyticus in vitro and in fish samples. The bacterial log reductions caused by the US and SAEW treatment for 15 min were 0.99 and 2.63 log CFU/ml in vitro, respectively, while SAEW-US combination achieved a 3.10 log reduction. MTT assay and protein leakage test showed that SAEW-US combination impaired cell viability and damaged cell membrane. In addition, compared to the US or SAEW treatment, SAEW-US combination induced higher reactive oxygen species (ROS) production, more apoptotic cells, and severer damage in bacterial cells. In spiked sliced tilapia samples, SAEW-US combination caused about 2 log reduction of inoculated pathogen. In conclusion, these findings demonstrate that SAEW-US combination could be potentially developed as an alternative strategy to control V. parahaemolyticus contamination in aquatic foods. Novelty impact statement SAEW-US combination effectively inactivates Vibrio parahaemolyticus, partly through inducing cellular ROS production, bacterial cell apoptosis, and microstructural changes. SAEW-US combination reduces the level of V. parahaemolyticus in spiked tilapia samples. SAEW-US combination could be potentially developed as an alternative strategy to control V. parahaemolyticus in aquatic foods.

Variation of Soil Microbial Community and Sterilization to Fusarium oxysporum f. sp. niveum Play Roles in Slightly Acidic Electrolyzed Water-Alleviated Watermelon Continuous Cropping Obstacle.

It is critical to exploit technologies for alleviating watermelon continuous cropping obstacle which frequently occurs and results in the limiting production and economic losses of watermelon. This study aimed to explore the effects of slightly acidic electrolyzed water (SAEW) on watermelon continuous cropping obstacles. The results showed that SAEW significantly improved the growth of watermelon seedlings cultivated in continuous cropping soil and caused a mass of changes to the diversity of the soil microbial community. Compared with Con, SAEW decreased the diversity index of bacteria by 2%, 0.48%, and 3.16%, while it increased the diversity index of fungus by 5.68%, 10.78%, and 7.54% in Shannon, Chao1, and ACE index, respectively. Besides, the enrichment level of Fusarium oxysporum f. sp. niveum (FON) was remarkably downregulated by 50.2% at 14 days of SAEW treatment, which could decrease the incidence of Fusarium wilt disease. The wet and dry weights of FON mycelia in the fluid medium were depressed more than 93%, and the number of FON colonies in continuous cropping soil was reduced by 83.56% with SAEW treatment. Additionally, a strong correlation between watermelon, FON, and SAEW was presented by correlation analysis. Furthermore, the content of endogenous reactive oxygen species (ROS) was over quadruply increased by SAEW, which may contribute to the sterilizing effect of SAEW on FON. Taken together, our findings demonstrated that exogenous SAEW could alter the soil microbial diversity and decrease the accumulation of FON, which improved the growth of watermelon seedlings and finally alleviated continuous cropping obstacles of watermelon.