Alkaline Electrolyzed Water Research Articles

Alkaline electrolyzed water-assisted ultrasonic extraction of lutein from daylily (Hemerocallis spp.): Structural preservation and activity evaluation

During lutein extraction, isomerization from all-trans to cis form reduced stability and antioxidant capacity. Alkaline electrolyzed water (AEW), with its reduced-state and small molecular clusters, effectively extracted bioactive substances and inhibited oxidation. Thus, an AEW-assisted ultrasonic extraction method was used to extract lutein from daylily. Compared to ultrasonic extraction alone, AEW treatment increased the lutein yield by 60 %. Structural analysis confirmed the preservation of all-trans lutein by AEW. Assess AEW extraction's impact on lutein's bioactivity by examining its protection against blue light cell damage. The results showed that that lutein extracted using AEW exhibited enhanced antioxidant capacity, significantly boosting the viability of ARPE-19 cells and the activity of intracellular antioxidant enzymes, thereby mitigating oxidative stress damage to the retina caused by blue light exposure. This study provided an effective method for efficiently extracting bioactive substances and preventing the impact of the extraction process on their structure and function.

The adaptability of polycarboxylate superplasticizer in alkaline electrolyzed water (AEW)-based cement composites containing clay: Workability and mechanical properties

Improving the adaptability of polycarboxylate superplasticizers (PCE) in high-clay content mortar is of great significance in enhancing the workability and mechanical properties of mortar containing clay. In this study, the potassium-based alkaline electrolyzed water (AEW) was used as mixing water for cement mortar. The excellent properties of AEW enabled PCE to be more compatible in cement mortar containing montmorillonite (MT) or kaolin (GL), improving the performance of mortar containing clay. The results showed that compared with ordinary tap water (OTW), the adsorption rate of clay minerals on PCE decreased in the AEW environment, and the clay interlayer spacing of MT was also reduced. AEW can inhibit the intercalation and adsorption of PCE molecular side chains by clay minerals to some extent. However, due to its unique crystal structure, the adsorption of MT on PCE was still significantly higher than that of GL. At the same time, increasing the content of clay mineral led to a decrease in mortar performance. Compared with the GL series, the MT series had a more significant negative impact on mortar fluidity and strengths. AEW also can promote hydration reactions, release more hydration heat, and produce more hydration products to encapsulate clay particles, thereby improving the workability and mechanical properties of cement paste containing clay. Furthermore, the high-activity AEW is rich in positively charged metal ions that can interact with clay minerals preferentially over cement particles, which enables the clay interlayer structure to be quickly saturated by AEW water molecules, effectively hindering the adsorption of PCE by clay minerals. However, in both the OTW and AEW environments, the intercalation effect of GL on PCE molecular side chains was not significant. Therefore, AEW has great potential in improving the adaptability of PCE in muddy cement pastes, which can help to enhance the workability and mechanical properties of muddy cement composites. This study provides theoretical references for preparing high-performance anti-clay concrete.

Assessing the efficacy of electrolyzed water for sanitizing contaminated stainless-steel surfaces in the meat industry

Electrolyzed water (EW) presents promising potential as an alternative sanitation solution, offering cost savings and eliminating the need for harsh chemicals in food factories. This study investigates EW's efficacy in cleaning contaminated stainless-steel plates. Some plates were covered with meat residues, and the upper side of the plate's surfaces were inoculated with Escherichia coli ATCC 10536. Plates were then immersed in sterile distilled water (SDW) (pH: 7 ± 1), acidic electrolyzed water (AcEW) (free chlorine: 4.21 ± 0.05 mg/L, oxidation-reduction potential (ORP): 1168 ± 3.54 mV, pH: 2.74 ± 0.03), or alkaline electrolyzed water (AlEW) (ORP: 817 ± 8.49 mV, pH: 11.38 ± 0.01), at different temperatures (30 or 50 °C) for 30 s. The cleanliness of plates was confirmed microbiologically when no E. coli was detected, (below 1.0 log CFU/cm2). Treatment with SDW resulted in a modest reduction of the E. coli by 1.67 ± 0.84 log CFU/cm2 (±70% of the survived population). At 30 °C, E. coli was undetectable when AlEW was used without meat residue. At 50 °C, E. coli was undetectable when either AcEW or AlEW was used without meat residue. Visual and tactile inspections were conducted to validate cleanliness. The visual examination was performed after cleaning the plates with EW to ensure they appeared clean. However, tactile inspection indicated the presence of residues. Subsequent microbial analysis revealed 1.50 ± 0.87 log CFU/100 cm2 (±36% of the surviving population) of E. coli. This study demonstrated that meat residues on food-contact surfaces create a barrier to sanitation, necessitating mechanical action and heat for improved cleanliness.

Alkaline electrolyzed water AS a potential green degreaser for meat processing stainless steel surface

AbstractThe meat industry faces significant challenges regarding removing fat, oil, and grease (FOG) residues from meat processing stainless steel surfaces, compounded by limited resources and inadequate cleaning knowledge. As an innovative solution to these difficulties, alkaline electrolyzed water (AlEW), a sustainable green degreaser, is proposed to replace the traditional alkaline wash. AlEW is produced through two–chamber (membrane) electrolysis at the cathode. AlEW with a strong reducing potential (−800 to −900 mV), high pH (10.0–11.5), and high dissolved oxygen are used to remove FOG residues from meat processing stainless steel surfaces. Our comprehensive analysis highlights the advantages of AlEW as a sustainable alternative to conventional degreasers for the meat industry, including ease of use, no storage requirements, and reduced costs for wastewater treatment. Our findings underscore AlEW's potential to improve the meat industry's quality, safety, and environmental sustainability. This review contributes to ongoing discussions about sustainable food industry solutions, aligning with the 2030 Agenda for Sustainable Development goals. In conclusion, AlEW is a promising alternative to conventional degreasers, advancing sustainability in the meat industry.Practical ApplicationsThis research introduces an innovative solution to a significant challenge in the meat processing industry—effective removal of fat, oil, and grease residues from equipment surfaces. Traditional methods involving costly and environmentally harmful chemicals have drawbacks. Our study proposes the use of alkaline electrolyzed water (AlEW) as a green degreaser. AlEW, generated by passing electric current through saltwater, exhibits high alkalinity that dissolves residues efficiently. This eco‐friendly approach not only ensures thorough cleaning but also reduces costs and addresses environmental concerns. By offering a sustainable and cost‐effective alternative, AlEW has the potential to revolutionize cleaning practices in the meat industry, enhancing food safety, operational efficiency, and sustainability. This advancement holds promise for wider adoption, benefiting both producers and consumers alike.

Bactericidal efficacy and mechanism of alkaline electrolyzed water co‐action with acidic electrolyzed water on Pseudomonas aeruginosa biofilm

AbstractHere, the bactericidal efficacy and mechanism of action of the combination of alkaline electrolyzed water (AlEW) and acidic electrolyzed water (AcEW) on Pseudomonas aeruginosa biofilm were investigated, in comparison with single AcEW or AlEW treatment. The mature P. aeruginosa biofilm was formed at 120 h of cultivation. The number of bacteria in the P. aeruginosa biofilm decreased by 7.87 and 2.51 Lg CFU/mL after single AcEW and single AlEW treatment for 8 min, while the sterilization rate reached 92.2% and 33.1%, respectively. The group of AcEW (7 min) co‐action with AlEW (1 min) had a P. aeruginosa sterilization rate of 85%. The AlEW (3 min) co‐action with AcEW (5 min) treatment showed the best bactericidal efficacy. With this treatment, the sterilization rate achieved 94.4%, and the extracellular protein, polysaccharide, and DNA were degraded with the ratios of 70.8%, 77.7%, and 70.5%, respectively. Thus, AlEW exhibited a major washing effect, which can destroy the biofilm structure of extracellular polymers to a certain extent, while AcEW displayed a significant bactericidal effect. These results suggest that the AlEW co‐action with AcEW treatment may be a promising candidate suitable for bacterial biofilm sterilization.

Antioxidant Activity Enhancement Effect of Silver-Ionized Water: Silver Cation Prepared by Electrolysis

In the present study, tap water, alkaline electrolyzed water (AlEW) and tourmaline water (TMW) were used as the electrolytes to generated the silver-ionized water (SIW), AlEW-SIW and TMW-SIW, respectively. The antioxidant properties of the samples containing ascorbic acid (AsA) were investigated by WST-kit method. The results showed that the SOD activity of AsA (2 mmol/L) dissolved in SIW (66.0%) was enhanced by about 8% compared to that of the tap water (57.9%). The SOD activity of the AlEW-SIW solution (77.3%), which was higher than that of the SIW solution, and lower than that of the AlEW solution (83.6%). The SOD activity of the TMW-SIW solution (83.0%) was similar to that of the TMW solution (82.5%). Furthermore, to classify the sample solutions, discriminant analyses were performed based on near infrared (NIR) spectral data, which was consistent with the results of the WST-kit method. The SOD activity of the AlEW-SIW and TMW-SIW solutions decreased slowly with storage time, and their SOD activities were higher than that of AlEW, TMW and the tap water solutions at storage time of 14 days. In summary, AlEW-SIW and TMW-SIW showed similar antioxidant activity enhancement as AlEW and TMW, and they also maintained the stability of the antioxidant activity of AsA during storage.

Preparation and application of a novel alkaline electrolyzed water for the adsorption resistance of superplasticizer and rapid hydration in cement composites

The high adsorption of cement composites owing to high clay content hinders the application of superplasticisers in architecture. In this study, novel alkaline electrolysed water (AEW) instead of ordinary mixing water (OMW) was introduced into cement composites to achieve high clay adsorption resistance and better mechanical strength of superplasticisers. The experimental results show that the AEW enhanced early hydration, and the 3-d compressive and flexural strength increased by 29.6% and 5.6%, respectively. In addition, the fluidity of the AEW mortar with 2% bentonite increased by 15.1%. Based on the results of saturated water absorption, the introduction of AEW effectively reduced the adsorption of polycarboxylate ether (PCE) superplasticiser, which improved the workability and mechanical strength. In conclusion, compared with traditional clay resistance methods, the use of AEW presents a high potential for the development of low-cost and low-carbon cement composites in restraining the high adsorption of PCE superplasticisers, which significantly improves the mechanical and hydration properties.

Effect of Functional Water on the Antioxidant Property of Concentrated Reconstituted Juice.

People often consume juice to easily ingest antioxidants, which can scavenge free radicals and reduce the risk of lifestyle-related diseases. In this study, the SOD assay kit-WST method was used to evaluate the antioxidant activity of two types of functional water, alkaline electrolyzed water (AlEW) and tourmaline water (TMW), reconstituted commercially available (Tropicana) and freshly squeezed concentrated juices and the effect of functional waters on physicochemical parameters and sensory evaluation of reconstituted juices was also analyzed. The reconstituted juice exhibited the highest antioxidant activity when the electrolysis current of AlEW was 8A or the tourmaline stone treatment temperature of TMW was 75 °C. Compared with the control group (69.4%), SOD activity of the reconstituted orange juice in the 8A-AlEW (77.2%) and 75 °C-TMW (84.5%) groups increased by 7.8 and 15.1%, respectively. Furthermore, the color and pH of the functional water reconstituted juice were not significantly different from the juice before concentration, and the taste was better. In summary, functional water could enhance the antioxidant activity of concentrated juice as a formula which could provide novel ideas for the development of functional beverages with antioxidant properties.

Effect of household sanitizing agents and electrolyzed water on Salmonella reduction and germination of sunflower and roselle seeds

Sprout consumption has become more popular due to a new variety of sprouts being introduced to the market. However, sprout seeds are a major source of sprout contamination and have been linked to most sprout-associated foodborne outbreaks. This study investigated Salmonella reduction in sunflower and roselle seeds using various sanitizing agents including water, water at 55 °C, sodium hypochlorite (NaOCl), diluted vinegar, acidic electrolyzed water (ACEW), and alkaline electrolyzed water (ALEW). Diluted vinegar containing 1.25% (v/v) acetic acid was the most effective treatment to inactivate Salmonella in sunflower seeds, resulting in a 3.82 log reduction after 15-min treatment. High concentrations of NaOCl (available chlorine concentration (ACC) 1692 mg/L) and ACEW (pH 2.76, oxidation-reduction potential 1093 mV, ACC 48 mg/L) had significantly lower antimicrobial activity with 3.20 and 2.39 log reduction, respectively, after 15-min treatment. Disinfecting roselle seeds for 15 min with water at 55 °C and diluted vinegar had comparable efficacy to reduce Salmonella by 2.54 and 2.48 log, respectively. There were no significant changes in Salmonella reduction among the high and low concentrations of NaOCl containing ACC 79 and 1692 mg/L, respectively, and ACEW in roselle seeds during 5–15 min of exposure time. All tested treatment solutions had no negative impact on the percentage of seed germination with over 96% and 92.56–95.89% for sunflower and roselle seeds, respectively. Conversely, the fresh weight and length of sunflower and roselle sprouts were influenced significantly by the types of sanitizing agents used for decontaminating the seeds. Collectively, our findings may contribute to the development of effective seed sanitization measure for sunflower and roselle seeds to reduce the risk of Salmonella-associated outbreaks linked to sprout consumption.

The neutralizing effect of mouth rinsing with alkaline electrolyzed water on different regions of the oral cavity acidified by acidic beverages.

Acids contained in foods and drinks are involved in the initiation and progression of dental erosion which causes tooth wear. The authors evaluated the neutralizing activity of alkaline electrolyzed water (AEW) in vitro and in vivo. The neutralizing ability of AEW against eight beverages was investigated in vitro. Furthermore, in an in vivo study, the effect of mouth rinsing with AEW on the pH of the oral cavity acidified with acidic beverages was examined. Following mouth rinsing, the oral pH was measured using a pH meter with a micro pH-sensor at the cervical surface of the mandibular teeth and the surface of soft tissues. Regarding the neutralizing ability, the higher the pH of the AEW, the lower the volume required for neutralization of the tooth surface. Changes in the pH by mouth rinsing with AEW and purified tap water (PTW) were analyzed. The degree of increase of pH with AEW was greater than with PTW at almost all sites. These results suggest that AEW has the potential to prevent the initiation and progression of dental erosion. Mouth rinsing with AEW could be a simple and effective way to prevent the initiation and progression of dental erosion and dental caries.

Effect of High Hydrostatic Pressure Treatment Combined with Alkaline Electrolyzed Water on the Injury and Growth Characteristics of Bacterial Spores.

The characteristics of growth and injury of Bacillus subtilis spores whose heat resistance was reduced by the treatment of high hydrostatic pressure processing (HPP) combined with/without alkaline electrolyzed water (AlEW) were investigated. The delay in the lag phase of growth curve observed when used in combination with AlEW, especially at 50 MPa or less, and was prolonged by about 4 to 6 hours. However, the effects of temperature and time during treatment on the lag phase were not significantly different between solo-HPP and in combination with AlEW. The injury characteristics of the treated bacterial spores were evaluated by using antibiotics (penicillin G, rifampicin and chloramphenicol) supplemented trypticase soy broth. In the chloramphenicol supplemented TSB, although the lag phase of bacterial spores treated by HPP with AlEW was not prolonged as compared with the normal-TSB, the decrease in growth rate during logarithmic phase and increase in maximum growth amount were observed. This result could suggest due to a damage by combined treatment of HPP with AlEW such as the inhibition of protein synthesis. Furthermore, the combined treatment with AlEW increased the catalase activity by 1.45, 1.63 and 4.25 times at 30, 80 and 100 MPa, respectively, as compared with solo-HPP, therefore the combined treatment could cause high oxidative stress on bacterial spores.

Effects of carbohydrate-electrolyte dissolved alkaline electrolyzed water on physiological responses during exercise under heat stress in physically active men.

PurposeThis study investigated the effects of 1400 mL intake of alkaline electrolyzed water (AEW) or purified water (PW) into which carbohydrate-electrolyte (CE) was dissolved on improving physiological responses during exercise under heat stress.MethodsThis double-blinded, crossover randomized controlled trial included 10 male participants who completed two exercise trials in a hot environment (35 °C, ambient temperature, and 50% relative humidity) after consuming CE-dissolved PW (P-CE) or CE-dissolved AEW (A-CE). The exercise trial consisted of running for 30 min on a treadmill (at an intensity corresponding to 65% of heart rate reserve adjusted for heat stress conditions) and repeated sprint cycling (10 × 7-s maximal sprint cycling), with a 35-min rest interval between the two exercises, followed by a 30-min post-exercise recovery period. Before and after running, and after cycling, the participants drank P-CE (hydrogen concentration of 0 ppm, pH 3.8) or A-CE (0.3 ppm, pH 4.1). Blood samples were obtained before, during (rest interval between running and cycling), and post-exercise.ResultsRepeated sprint performance and oxidative stress response did not differ between the P-CE and A-CE trials. A-CE consumption significantly attenuated the increase in blood lactate concentration during the running exercise but not during repeated sprint cycling under heat stress conditions.ConclusionOur findings suggested that A-CE did not significantly affect repeated sprint performance; however, the attenuated elevation in blood lactate by A-CE ingestion implies a partial enhancement of endurance performance during submaximal exercise under heat stress.

Efficient enzymatic production of angiotensin I-converting enzyme inhibitory peptides from three protein-rich materials by electrolyzed water pretreatment

Three protein-rich materials were pretreated with a self-designed alkaline electrolyzed water (AEW) pretreatment equipment to promote the release of angiotensin I-converting enzyme (ACE) inhibitory peptides by improving hydrolysis efficiency. According to degree of hydrolysis (DH) and ACE inhibitory activity, defatted walnut meal (DWM) was selected to study antihypertensive activity by hydrolysis in assistance of AEW pretreatment. It was found DWM pretreated with AEW at pH 11.5 followed by Alcalase hydrolysis exhibited the highest DH (21.96%), protein recovery rate (94.76%), and ACE inhibitory activity (IC50 of 0.137 mg/mL), in which AEW pretreatment resulted in the transformation of α-helix and β-turn to random coil and the destruction of hydrogen bonds to expose more cleavage sites to enhance hydrolysis efficiency. Thereafter, ACE inhibitory peptides GIENYRVV (IC50 of 0.102 mg/mL) and AGRISTVNSHTLPVL (IC50 of 0.20 mg/mL) were identified from the hydrolysate. Overall, AEW pretreatment was an innovative strategy to promote the release of antihypertensive peptides during hydrolysis.

Impacts of alkaline‐electrolyzed water treatment on physicochemical, phytochemical, antioxidant properties and natural microbial load on ‘Granny Smith’ apples during storage

SummaryProviding consumers with fresh and safe fruit can greatly increase their access to recommended daily intake of phytonutrients. Thus, this study investigated the impact of dipping in alkaline electrolyzed water (AEW) and dipping duration on the physicochemical, phytonutrients and microbial load on ‘Granny Smith’ apples. Apples treated with AEW (200 and 300 mg L−1) were compared to sodium hypochlorite (NaOCl, 200 mg L−1) and to non‐treated (control) under dipping durations of 10 and 15 min. Apples treated with AEW maintained titratable acidity (TA) and total soluble solids (TSS) compared to other treatments (P > 0.05). Interaction of treatments and storage duration had a significant impact (P ≤ 0.05) on total phenolics and flavonoids contents. Apples treated with AEW better maintained antioxidant capacity compared to control. Treatments with AEW resulted in ≈2 Log reduction in total aerobic mesophilic bacteria (4.1 Log CFU cm−2 to 2.2 Log CFU cm−2) and < 1 Log reduction for yeasts and moulds (3.9 Log CFU cm−2 to 2.7 Log CFU cm−2). This study demonstrated the efficacy of electrolyzed water treatment as an alternative to conventional pack‐house practices for apple fruit.

Effects of alkaline electrolyzed water pretreatment on the physicochemical quality attributes of fresh nectarine during storage

Chlorinated water treatment has been extensively used to manage postharvest decontamination of fruits for decades. It has been well established that chlorine may produce undesirable by-products that have a potential carcinogenic impact on human health and toxic waste on the environment. Electrolyzed water is an eco-friendly technique that has been regarded as an effective method for decontaminating microbes on fruit surfaces. However, the impact of alkaline electrolyzed water (AEW) on the physical and biochemical quality attributes of nectarine fruit during postharvest storage is not fully understood. Therefore, this study investigated the effects of AEW treatment (200 mg/L, pH, 6.7), sodium hypochlorite, and nontreated (control) on the storability, quality attribute, and decay incidence of fresh nectarine stored at −0.5℃ and 95% RH for 31 days. Results obtained indicated that the AEW treatment effectively maintains firmness, reduced weight loss, and maintains high total soluble solid content with a slight decline in titratable acidity for nectarines. Furthermore, the AEW suppresses the decrease of color qualities of the peel L*, a*, b*, reduced the incidence of browning (h°) and surface decay compared with chlorine-treated and control fruit. Novelty impact statement Alkaline electrolyzed water (AEW) and its efficacy to minimize decay and maintain physicochemical quality of nectarine fruit compared with chlorinated water treatment were investigated. Treatment with AEW (200 mg/L, 10 min) effectively preserves the freshness of the nectarine fruit by reducing surface decay compared with the chlorine-treated and control fruit. The outcome of this study provides guiding tools for stone fruit pack-houses and other industry role players on the potential of EW as an alternative to chlorine treatments.

Stability of electrolyzed water: from the perspective of food industry

Green cleaner and disinfectant can provide a better environment and they can reduce cleaning cost by eliminating the cost of harsh cleaning chemicals, minimizing cleaning chemicals storage space, reducing cost for wastewater treatment and reducing logistics cost for chemical supply. This study explored the personal view of Small and Medium Enterprises (SMEs) top to bottom workers towards the challenges during cleaning and disinfection process and their readiness in accepting a green cleaner and disinfectant. In this work, the advantages and disadvantages of electrolyzed water (EW) as green cleaner and disinfectant were discussed. A lab-scale batch ion-exchange membrane electrolysis unit was used to produce acidic electrolyzed water (AcEW) and alkaline electrolyzed water (AlEW). The stability of AcEW and AlEW was also studied based on its physical changes (pH, oxidative-reduction potential (ORP), chlorine content and hydrogen peroxide content) in 7 days of storage, whereby measurements were taken daily. The pH maintained for both AcEW and AlEW during the 7 days of storage. The ORP maintained at plateau for the first 5 days of AcEW storage. After 5 days, AcEW showed a decreasing trend. While ORP for AlEW increases drastically between day 1 and 2. Then, the ORP reaches a plateau after three days. The amount of free chlorine, total chlorine and hydrogen peroxide content was 10 mg/L, respectively, on the day of production. However, all the properties decreased gradually and there were no chlorine and hydrogen peroxide detected on the 7th day. The results from this study can be used as a guideline to store the EW and to understand the stability of the EW, which can benefit the SME food manufacturers.

Conceptual design of portable electrolyzed water cleaning rig using TRIZ method

The limited budget allocation and storage chemicals space are the main reasons food SMEs manufacturers took cleaning and sanitation for granted. A portable Electrolyzed Water Cleaning Rig which can generate sanitation solution and at the same time generated high-speed water will ease the cleaning and sanitation process for SMEs. In this study, the theory of inventive problem solving (TRIZ method) is applied in the development of portable electrolyzed water cleaning rig. A new conceptual design for the rig, which is robust and affordable is proposed. The rig could improve cleaning efficiency significantly in SME food industry in Malaysia, which is a major cause of a low number of SME with GMP certification. However, the final conceptual design has to undergo several modifications for assembly and manufacturing purposes, which will be performed in further study. The idea of generation for the portable electrolyzed water cleaning rig design was illustrated based on the TRIZ contradiction matrix. This portable unit will be able to generate both strongly acidic electrolyzed water (AcEW) and strongly alkaline electrolyzed water (AlEW) solution continuously. Both cleaning solutions are green cleaning solutions which can replace the commercial cleaning sanitation solutions. The development of the conceptual design of the portable Electrolyzed Water Cleaning Rig will help food SMEs tremendously.

The effects of ingestion of hydrogen-dissolved alkaline electrolyzed water on stool consistency and gut microbiota: a double-blind randomized trial

A relationship between Bifidobacterium and defecation has previously been reported. Our hypothesis on the effectiveness of alkaline electrolyzed water (AEW) proposes that ingestion of AEW, considered possessing antioxidative properties, increases the number of Bifidobacteria and improves stool hardness and gastrointestinal symptoms. A double-blind, randomized study was conducted to evaluate the connection between stool consistency and change in gut microbiota composition induced by drinking hydrogen-dissolved AEW. The participants drank 500 mL of purified tap water or AEW every day for 2 weeks. In this study, drinking AEW did not drastically change gut microbiota, but it appeared to act on a specific bacterial species. Drinking AEW was confirmed to cause an increase in Bifidobacterium. The AEW group also saw stool consistency significantly converge to Bristol stool scale Type 4 (“normal”). Therefore, it is highly likely that the gut microbiota will be changed by drinking AEW. This study was retrospectively registered in University Hospital Medical Information Network (UMIN) Clinical Trials Registry (UMIN ID: UMIN000039507) on February 18, 2020, and was approved by the Ethics Committee of University of Yamanashi (approval No. H30-25) on January 9, 2018.

Effect of Alkaline Electrolyzed Water on Performance Improvement of Green Concrete with High Volume of Mineral Admixtures

The strength and durability of concrete will be significantly reduced at high volume of mineral admixture, and the poor early strength of concrete also still needs to be solved. In this investigation, a highly active alkaline electrolyzed waters was used as mixing water to improve the early strength and enhance the durability of green concrete with high volume mineral admixture, the influences of alkaline electrolyzed water (AEW) on hydration activity of mineral admixture and durability of concrete were determined. The results showed that compared with natural tap water, AEW can accelerate early hydration process of cement in concrete and produce comparatively more hydrated products, leading to a 13.6% higher compressive strength than that of ordinary concrete at early age, but the improvement effect of AEW concrete was relatively reduced at long-term age. Meanwhile, the activity of mineral admixtures could be stimulated by AEW to some extent, the strength and durability performance of AEW concrete after double doping 25% slag and 25% fly ash can still reach the level of ordinary cement concrete without mineral admixtures. The SEM micromorphology of 7 d hydrated natural tap water cement paste was observed to be flaky and tabular, but the AEW cement pastes present obvious cluster and granulation phenomenon. The SEM microstructure of AEW concrete with mineral admixtures is more developed and denser than ordinary tap water concrete with mineral admixtures. Therefore, the AEW probably could realize the effective utilization of about 50% mineral admixture amount of concrete without strength loss, the cement production cost and associated CO2 emission reduced, which has a good economic and environmental benefit.

Effect of the Combination of High Hydrostatic Pressure and Alkaline Electrolyzed Water on the Reduction of Heat Resistance of Bacterial Spores.

The effect of combined use of alkaline electrolyzed water （AlEW） on the reduction of heat resistance of bacterial spores by high hydrostatic pressure processing（ HPP） was investigated in this study. No reduction of heat resistance of bacterial spores, which was defined as the spore survival by heat treatment at 80℃ for 15 min, was observed by the treatment of single HPP with 30MPa at 50℃ even for 6 hours. However, a 3-log decrease in the viable bacterial spores was obtained by the combination of AlEW pretreatment with 1 hour of HPP treatment. An additional 2 hours duration of HPP treatment could inactivate more 2 logs of the viable bacterial spores. The obtained D value of bacterial spores treated by HPP was decreased to one-eighth by the pretreatment with AlEW when compared with the control sample. In case of the temperature during HPP treatment was 70℃, bacterial spores did not reduce its heat resistance with lower pressuring levels. In case of the temperature during HPP treatment is high with lower pressure levels, bacterial spores did not reduce its heat resistance even when AlEW was combined as the pretreatment. It was considered that the decrease in heat resistance by AlEW was resulted from the weakening of surface layer of spores by protein dissolution with alkaline substance. No clear effect of high negative redox potential, which is a unique property of AlEW, on the reduction of heat resistance was recognized.