Evaluation of pre-treatments for shelf life extension of minimally processedfenugreek (Trigonella foenum graecum L.)

Efficacy of neutral electrolyzed water (NEW) for reducing microbial contamination on minimally-processed vegetables

Consumption of fresh-cut fruit has increased in the latest years. This type of product is more susceptible to microbial contamination. For this reason disinfection is a very important step in fresh-cut processing. Chlorine is the most common disinfectant in the fresh-cut industry but due to environmental and health risks caused by the use of this disinfectant there is a demand to develop new sanitizers. Electrolyzed water appears to be a promising alternative to chlorine sanitizers showing to be a broad spectrum microbial decontamination agent. Neutral electrolyzed water (NEW) and acidic electrolyzed water (AEW) can be used as microbial decontamination agents on fresh-cut fruits. The biocidal activity of NEW, AEW and sodium hypochlorite were evaluated to inactivate pure cultures of foodborne pathogens on the surface of fresh-cut apples, pears and oranges. Fruits were inoculated with Listeria innocua or Escherichia coli O157:H7 and treated with NEW, AEW at different concentrations and different times of exposure. The NEW and AEW treatments were compared with sodium hypochlorite and deionised water (control). The bacterial population was significantly reduced in all fruits treated with AEW at 200 ppm of free chlorine. Treatments with the AEW with 100 ppm free chlorine resulted in reductions higher or similar to NEW or sodium hypochlorite at the same content of free chlorine, and in general the effect of NEW was similar to H In conclusion, AEW or NEW seems to be a promising disinfection technique to reduce the amount of free chlorine used for the disinfection of fresh-cut fruits representing a safer way to ensure food safety in these products.

The main objective of this study is to apply neutral electrolyzed water (NEW) spraying to inactivate bioaerosols. We evaluated the inactivation efficiency of NEW applied to inactivate two airborne bacterial Escherichia coli and Bacillus subtilis aerosols inside an environmental-controlled chamber in the study. Generated with electrolyzing 6.15 M sodium chloride brine, the NEW with free available chlorine (FAC) concentration 50, 100, and 200 ppm was pumped with an air pressure of 70 kg/cm2 through nozzle into the chamber to inactive E. coli and B. subtilis aerosols precontaminated air (initial counts of 3 × 104 colony-forming units [CFU]/m3). Bacterial aerosols were collected and cultured from chamber before and after NEW spray. The air exchange rate (ACH, hr−1) of the chamber was set to simulate fresh air ventilating dilution of indoor environment. First-order concentration decaying coefficients (Ka, min−1) of both bacterial aerosols were measured as an index of NEW inactivation efficiency. The result shows that higher FAC concentration of NEW spray caused better inactivation efficiency. The Ka values under ACH 1.0 hr−1 were 0.537 and 0.598 for E. coli of FAC 50 and 100 ppm spraying, respectively. The Ka values of FAC 100 ppm and 200 ppm spraying for B. subtilis were 0.063 and 0.085 under ACH 1.0 hr−1, respectively. The results indicated that NEW spray is likely to be effective in inactivation of bacterial airborne contamination. Moreover, it is observed in the study that the increase of ventilation rate and the use of a larger orifice-size nozzle may facilitate the inactivation efficiency. Implications: Bacterial aerosols have been implicated in deterioration of air quality and occupational health. Effective, safe, and economic control technology is highly demanded, especially for agricultural and food industries. In the study, NEW mist spraying performed effectively in controlling E. coli and B. subtilis modeling bioaerosols contamination. The NEW revealed its potential as an alternative airborne disinfectant worth being discovered for improving the environmental quality in the future.

Electrolyzed water mainly containing hypochlorous acid is widely used because of its strong microbicidal effects, biosafety, and eco-friendliness. For frequent use in intraoral treatments, we focused on neutral electrolyzed water (NW) produced using two-stage electrolysis and investigated its storage stability. For standard-concentration NW preparations with a free available chlorine concentration (ACC) of 25, 35, and 50 mg/L and high-concentration NW preparations (100, 200, 300, 500, and 1000 mg/L), the changes in the pH, oxidation reduction potential, and ACC during a 126-day storage period and the bactericidal efficacies after storage were examined. Storage under non-shaded conditions at room temperature (LRT) and a higher ACC substantially altered the properties of the NW. NW (≤300 mg/L) had a pH of 5.9–7.3 even after storage under LRT; however, NW with a higher ACC (500 and 1000 mg/L) had a pH ˂ 5.5, critical for human enamel, even under shaded and refrigerated conditions (SLW). Only NW (25 mg/L) stored under LRT decreased the bactericidal effect (removal rate: 99.8%). When stored for use in intraoral treatments, NW should be prepared with an ACC of 25–300 mg/L and stored in SLW. It is suggested that stored NW, especially when diluting it, should be checked to ensure it maintains the properties appropriate for every intended purpose.

Bactericidal activity of neutral electrolyzed water against Bacillus cereus and Clostridium perfringens in cell suspensions and artificially inoculated onto the surface of selected fresh produce and polypropylene cutting boards

Efficacy of neutral electrolyzed water for sanitization of cutting boards used in the preparation of foods

The use of electrolyzed water as a disinfectant for minimally processed apples

The use of electrolyzed water as a disinfectant for fresh cut mango

Human norovirus (NoV) is the leading cause of acute gastroenteritis worldwide. Persistence on surfaces and resistance to many conventional disinfectants contribute to widespread transmission of norovirus. We examined the efficacy of neutral electrolyzed water (NEW; pH 7) for inactivation of human NoV GII.4 Sydney in suspension (ASTM method 1052-11) and on stainless steel surfaces (ASTM method 1053-11) with and without an additional soil load. The impact of the disinfectant on viral capsid was assessed using reverse transcriptase quantitative PCR (RT-qPCR; with an RNase pretreatment), SDS-PAGE, transmission electron microscopy, and a histo-blood group antigen (HBGA) receptor-binding assay. These studies were done in parallel with those using Tulane virus (TuV), a cultivable human NoV surrogate. Neutral electrolyzed water at 250 ppm free available chlorine produced a 4.8- and 0.4-log10 reduction in NoV genome copy number after 1 min in suspension and on stainless steel, respectively. Increasing the contact time on surfaces to 5, 10, 15, and 30 min reduced human NoV genomic copies by 0.5, 1.6, 2.4, and 5.0 log10 and TuV infectious titers by 2.4, 3.0, 3.8, and 4.1 log10 PFU, respectively. Increased soil load effectively eliminated antiviral efficacy regardless of testing method and virus. Exposure to NEW induced a near complete loss of receptor binding (5 ppm, 30 s), degradation of VP1 major capsid protein (250 ppm, 5 min), and increased virus particle aggregation (150 ppm, 30 min). Neutral electrolyzed water at 250 ppm shows promise as an antinoroviral disinfectant when used on precleaned stainless steel surfaces.IMPORTANCE Norovirus is the leading cause of acute viral gastroenteritis worldwide. Transmission occurs by fecal-oral or vomitus-oral routes. The persistence of norovirus on contaminated environmental surfaces exacerbates its spread, as does its resistance to many conventional disinfectants. The purpose of this research was to evaluate the antinoroviral efficacy of neutral electrolyzed water (NEW), a novel chlorine-based disinfectant that can be used at reduced concentrations, making it more environmentally friendly and less corrosive than bleach. An industrial-scale electrochemical activation device capable of producing relatively stable electrolyzed water at a wide pH range was used in this study. Experiments showed that 250 ppm NEW effectively eliminated (defined as a 5-log10 reduction) human norovirus GII.4 Sydney (epidemic strain) on clean stainless steel surfaces after a 30-min exposure. Supporting studies showed that, like bleach, NEW causes inactivation by disrupting the virus capsid. This product shows promise as a bleach alternative with antinoroviral efficacy.

The virucidal effects of two types of electrolyzed water, acidic electrolyzed water (AEW) and neutral electrolyzed water (NEW), on avian influenza viruses were studied. Virus titers of the highly pathogenic H5N1 virus and the low-pathogenic H9N2 virus irreversibly decreased by >5-log at 1min after the viruses were mixed with NEW containing ≥43ppm free available chlorine (FAC), but not with NEW containing <17ppm FAC. The minimum concentration of FAC for a virucidal effect of NEW was estimated at around 40ppm. In contrast, the virus titers decreased by >5 log at 1min after the viruses were mixed with AEW, in which the concentration of the FAC ranged from 72 to 0ppm. Thus, the virucidal effect of AEW did not depend on the presence of FAC. Reverse transcription polymerase chain reaction amplified fragments of the M and NP genes, but not the complete M gene, from RNA extracted from the AEW-inactivated virus. Moderate morphological changes were found under the electron microscope, although no changes were observed in the electrophoresed proteins of the AEW-inactivated virus. No viral genes were amplified from the RNA extracted from the NEW-inactivated virus, regardless of the length of the targeted genes. No viral particles were detected under the electron microscope and no viral proteins were detected by electrophoresis for the NEW-inactivated virus. Thus, this study demonstrated potent virucidal effects of AEW and NEW and differences in the virucidal mechanism of the two types of electrolyzed water.

In this study, the antimicrobial activity of neutral electrolyzed water (NEW) on Bacillus cereus forming endospore, Escherichia coli and, toxin producer Aspergillus flavus and Penicillium expansum was determined both on the surface of steel plates in the presence of organic matter artificially inoculated and in cell suspensions. Also, the antimicrobial efficiency of NEW was compared to that of Sodium hypochlorite (NaClO). Experiments were carried out at room temperature (22 °C). 1% sodium hypochlorite solution (with 531 ppm free chlorine), and different concentrations of NEW, 5% (with 63 ppm free chlorine), 10% (with 120 ppm free chlorine), and 15% (with 187 ppm free chlorine) were used for the comparison. Cell suspensions and stainless-steel plates inoculated with a final 10% liquid fig solution were treated with NEW and NaClO for 0 (untreated, control), 15, 30, and 60 seconds. Then, viable cell counts both in cell suspensions and on the inoculated stainless-steel plates were determined. It was determined that there were significant differences (P

Control of spoiler Pseudomonas spp. on fresh cut vegetables by neutral electrolyzed water

Aeromonas salmonicida isolates: Attachment ability and sensitivity to four disinfectants

Dextran is primarily produced from sucrose by the bacterial species Leuconostoc mesenteroides, which secretes an extracellular enzyme called dextransucrase. Dextran formation in sugarcane mixed juice during processing reduces profits by causing sucrose losses and degrading sugar quality. The results of this study showed that sucrose conversion rate in sugarcane mixed juice increased from 13.25 to 90.77%, and that dextran content increased from 3.58 to 66.07 mg/mL as fermentation time was extended from 6 to 84 h. Moreover, neutral electrolyzed water inhibited the growth of L. mesenteroides. Inhibition zone diameters gradually increased as NaCl concentrations increased from 0.10 to 6.4%. This result may be attributed to increments in free available chlorine concentrations with increasing NaCl content. The peak areas of sucrose, glucose, and fructose in the chromatograms of sugarcane mixed juice treated with neutral electrolyzed water remained unchanged, and the absence of dextran formation during 84 h of fermentation suggested that neutral electrolyzed water could reduce dextran synthesis and minimize sugar losses. The results of this study indicate that neutral electrolyzed water has important applications as an effective bacteriostatic to resolve the problem of L. mesenteroides contamination in sugar industry.

Recent multistate outbreaks and recalls of fresh apples due to Listeria monocytogenes contamination have increased consumer concerns regarding fresh and processed apple safety. This study aimed to evaluate the antimicrobial efficacy of two sanitizers, mineral oxychloride (JC9450) and neutral electrolyzed water (NEW), for inactivation of L. monocytogenes on fresh apples. A 2-min treatment of 0.125% (v/v) JC9450 with 100 ppm free available chlorine (FAC) or NEW with 110 ppm FAC caused 0.9–1.2 log10 CFU/apple reduction of L. monocytogenes on both Granny Smith and Fuji apples 24 h post-inoculation. Increasing JC9450 concentration to 0.25 and 0.50% significantly improved its bactericidal effect and reduced L. monocytogenes on Granny Smith apples by ~2.0 and 3.8 log10 CFU/apple, respectively, after a contact time of 2 min. At a shorter contact time of 30 sec, the inactivation efficacy of chlorine and 0.25–0.50% JC9450 against L. monocytogenes on apples was significantly reduced compared with the respective 2-min wash. Furthermore, no L. monocytogenes was recovered in deionized water prepared antimicrobial wash solution or on non-inoculated apples post-NEW with 110 ppm FAC or 0.125–0.5% JC9450 washes, indicating their ability to prevent cross-contamination. In addition, a 2-min exposure to NEW with 110 ppm FAC and 0.50% JC9450 reduced apple native microbiota including total plate count by 0.14 and 0.65 log10 CFU/apple, respectively, and yeast and mold counts by 0.55 and 1.63 log10 CFU/apple, respectively. In summary, L. monocytogenes attached on apples was difficult to eliminate. JC9450 and NEW demonstrated a dose-dependent reduction in L. monocytogenes on apples and successfully prevented cross-contamination, indicating their application potential in post-harvest washes of apples.