Food Surface Research
Recently, several reports about sterilization effect of electrolyzed water have been published. The electrolyzed water is expected as one of attractive application for sanitation of fresh food, however, to install this electrolyzed water, we have to clear the potential of the microorganism control for real food. In this paper, we try to reveal the mechanism of the microorganism control, and also try to check the food quality change during the treatment. Therefore, to evaluate the effect of the electrolyzed water, we examined the several test for making sterilization mechanism clear and observed microorganism behavior on food surface. At first, for the purpose of making sterilization effects clear in vitro condition, we did microorganism test with several injection ratio and number. Then, we studied the effects of catalase on the enumeration of stressed Escherichia coli cells after acidic electrolyzed water treatment. Moreover, we studied sterilization effect of acidic electrolyzed water for E. coli on an agar block on the assumption as one of food model. In addition, we studied sterilization effects for sliced raw tuna as one sample of food surface treatment. The change in the quality of food surface was observed by scanning electron microscope, color meter and so on. Steriliaation effects are dependent the condition of injection ratio and mixing numbers. These results suggest that it is important to keep available chlorine concentration for keeping the potential to the microorganisms'control. The increasing of E. coli number with the addition of catalase was suggested that the weak concentration of electrolyzed water gave the injured microbes. The Observation of cultivated E. coli behavior on agar block showed the microorganism behavior. Acidic electrolyzed water sterilizes microorganisms on sliced raw tuna, however, after treatment, the color change of surface of tuna and the protein denaturation were observed. These results suggest that when the electrolyzed water treatment is applied to control the microorganism on surface, the effect against food surface must be considered.
Read MoreActivity Against Influenza through in vitro Experiments
Hypochlorous acid (HOCl) solutions were evaluated for their virucidal ability against a low pathogenic avian influenza virus (AIV), H7N1. HOCl solutions containing 50, 100 and 200 ppm chlorine (pH 6) or their sprayed solutions (harvested in dishes placed at 1 or 30 cm distance between the spray nozzle and dish) were mixed with the virus with or without organic materials (5% fetal bovine serum: FBS). Under plain diluent conditions (without FBS), harvested solutions of HOCl after spraying could decrease the AIV titer by more than 1,000 times, to an undetectable level (< 2.5 log10TCID50/ml) within 5 sec, with the exception of the 50 ppm solution harvested after spraying at the distance of 30 cm. Under the dirty conditions (in the presence of 5% FBS), they lost their virucidal activity. When HOCl solutions were sprayed directly on the virus on rayon sheets for 10 sec, the solutions of 100 and 200 ppm could inactivate AIV immediately after spraying, while 50 ppm solution required at least 3 min of contact time. In the indirect spray form, after 10 sec of spraying, the lids of the dishes were opened to expose the virus on rayon sheets to HOCl. In this form, the 200 ppm solution inactivated AIV within 10 min of contact, while 50 and 100 ppm could not inactivate it. These data suggest that HOCl can be used in spray form to inactivate AIV at the farm level.
Read MoreCleaning Efficacy in Health Facilities
Objective: this study aimed to monitor the microbiological effect of cleaning near-patient sites over a 48 hour period with a novel sanitizer , electrolysed water. Setting: one acute care of the elderly ward in a district general hospital in Scotland. Results: there was an early and significant reduction in average ACC (360 sampled sites) from a pre-clean level of 4.3 to 1.65 cfu/cm 2 at one hour after sanitizer cleaning (p< 0.0001). Average counts then increased to 3.53 cfu/cm2 at 24 hours and 3.68 cfu/cm2 at 48 hours. Total MSSA/MRSA (34 isolates) declined by 71% at four hours after cleaning, but then increased to 155% (53 isolates) pre-clean levels at 24 hours. Conclusions: cleaning with electrolysed water reduced ACC and staphylococci on surfaces beside patients. ACC remained below pre-clean levels at 48 hours but MSSA/MRSA counts exceeded original levels at 24 hours after cleaning. While sanitizer cleaning quickly reduces bioburden, further investigation is required to clarify the reasons for rebound contamination of pathogens at near-patient sites.
Read MoreFood Service Application
Electrolyzed water (EW) is known by its bactericidal efficacy and capability to oxidize organic matter. The present research evaluated the efficacy of recently developed electrolytic cells able to generate higher concentration of reactive oxygen species using lower power and salt concentration than conventional cells. This study tested the inactivation of Escherichia coli O157:H7, the organic matter depletion and trihalomethane (THM) generation by EW in process wash water under dynamic conditions. To achieve this, clean tap water was continuously added up to 60 min with artificial process water with high chemical oxygen demand (COD) inoculated with E. coli O157:H7, in experiments performed in a pilot plant that recirculated water through one electrolytic cell. Plate counts of E. coli O157:H7, COD, THMs, free, combined and total chlorine, pH, temperature and oxidation-reduction potential were determined. Results indicate that the novel electrolysis system combined with minimal addition of NaCl (0.05%) was able to suppress E. coli O157:H7 population build-up and decreased the COD accumulation in the process wash water. THM levels in the water were relatively high but its concentration in the washed product was marginal. Highly effective electrolysis has been proven to reduce the occurrence of foodborne diseases associated to cross-contamination in produce washers without having an accumulation of THMs in the washed product.
Read MoreBacteria in Animal Housing
Slightly acidic electrolyzed water (SAEW) spray has been considered as a novel approach for airborne bacteria reduction in animal housing. This study aimed to optimize the operating parameters of SAEW spray based on the size distribution of sprayed aerosols, the available chlorine travelling loss in sprayed aerosols, and the reduction efficiency of airborne culturable bacteria (CB). The optimized operating parameters were the nozzle orifice diameter and the spray pressure. The size distribution characteristics of sprayed SAEW aerosols under different operating parameters were quantified. The pH and available chlorine concentrations of the original SAEW solution and the SAEW aerosols collected at 0 m, 0.25 m, 0.50 m, 0.75 m, and 1.00 m from the spray nozzle head were analyzed. A bioaerosol nebulizing generator was used to simulate animal housing environment in an environmentally-controlled chamber. Six SAEW spray trials under different operating parameters were conducted at a spray dosage of 80 mL/m2 in the chamber. Airborne CB concentrations before and after spray were measured to investigate the reduction efficiency of airborne CB. Dv(50), the volume-based diameter below which 50% of the particle being present, increased with the nozzle orifice diameter and decreased with the spray pressure. The travelling loss of available chlorine in the sprayed SAEW aerosols was greatly dependent on Dv(50). SAEW spray with medium size sprayed aerosols (Dv(50) = 86.62 μm, 67.94 μm, and 54.53 μm) showed significantly higher airborne CB reduction efficiencies than large (Dv(50)=121.80 μm and 96.00 μm) or small size aerosols (Dv(50) = 42.57 μm). The spray operating parameters that provide medium size sprayed aerosols (Dv(50) ~ 60-90 μm) are recommended for SAEW spray in animal housing.
Read MoreEfficacy of E-water Against Human Norovirus
Noroviruses (NVs) are the most frequent cause of outbreaks of gastroenteritis in common settings, with surface-mediated transfer via contact with fecally contaminated surfaces implicated in exposure. NVs are environmentally stable and persistent and have a low infectious dose. Several sanitizers have been evaluated for efficacy to control viruses on surfaces, but the toxicity and potential damage to treated materials limits their applicability. Sterilox hypochlorous acid (HOCl) solution (HAS) has shown broad-spectrum antimicrobial activity while being suitable for general use.
Read MoreTested Against Strains of Hospital Infections
The study is designed to investigate bactericidal actions of electrolyzed oxidizing water on hospital infections. Ten of the most common opportunistic pathogens are used for this study. Cultures are inoculated in 4.5 mL of electrolyzed oxidizing (EO) water or 4.5 mL of sterile deionized water (control), and incubated for 0, 0.5, and 5 min at room temperature. At the exposure time of 30 s the EO water completely inactivates all of the bacterial strains, with the exception of vegetative cells and spores of bacilli which need 5 min to be killed. The results indicate that electrolyzed oxidizing water may be a useful sanitizer for hospital infections, but its clinical application has still to be evaluated.
Read MoreE-water and Fungi
The objective of this study was to determine the efficacy of electrolyzed oxidizing (EO) water in reducing natural microbiota on radish seed and sprout during seed soaking and sprouting. EO water with different available chlorine concentrations (ACC, 15, 20, 28, 33 and 40 mg/L) and different pH (2.5, 3.5, 4.5, 5.5 and 6.5) were used to soak radish seeds for 12 h and the surviving population of total aerobic bacteria, yeast and mold, and germination rate were determined. On the other hand, EO water with ACC of 30 and 50 mg/L was applied to spray sprouts during seed sprouting and the antimicrobial efficacy of EO water, as well as length, gross weight and dry weight of sprout were evaluated. The results showed that the population of natural microbiota decreased with increasing ACC of EO water, while no significant difference was observed among EO waters with different pH levels that were applied while soaking the seeds. EO water with higher ACC and lower pH slightly reduced the germination percentage of radish seed during seed soaking. EO waters with ACC of 30 and 50 mg/L sprayed during seed sprouting resulted in 1.39 and 1.58 log reductions of total aerobic bacteria, yeast and mold, respectively, and improved the length, gross weight and dry weight of the sprouts. Therefore, EO water with low ACC and near neutral pH could be used to soak seeds and water sprouts throughout seed germination and sprouting to control the population of natural microbiota on seeds and sprouts.
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