Electrolyzed Oxidizing Water Research Articles

Evaluation of bactericidal activity of weakly acidic electrolyzed water (WAEW) against Vibrio vulnificus and Vibrio parahaemolyticus

Vibrio parahaemolyticus and Vibrio vulnificus cause severe foodborne illness in humans; thus, to reduce outbreaks of disease, it is clearly important to reduce food contamination by these pathogens. Although electrolyzed oxidizing (EO) water has been reported to exhibit strong bactericidal activities against many pathogens, it has never been tested against V. vulnificus and V. parahaemolyticus. The purpose of this study was to evaluate the bactericidal activity of weakly acidic electrolyzed water (WAEW), a type of EO water, against V. vulnificus and V. parahaemolyticus. Cell suspensions and cell cultures of both pathogens were treated for 30 s with sodium hypochlorite solution containing 35 mg/L available chlorine concentration (ACC) or WAEW containing 35 mg/L ACC. After an initial inoculum of 5.7 log CFU/mL, the number of viable V. vulnificus cells was reduced by 2.2 logs after treatment for 60 s with sodium hypochlorite solution containing 35 mg/L ACC, while no cells survived treatment with WAEW for 30 s. Similar results were obtained for V. parahaemolyticus. Under open storage conditions, WAEW maintained bactericidal activities against cell suspensions of both strains after 5 weeks but disappeared against cell cultures of the two strains after 5 weeks. Under closed storage conditions, however, WAEW maintained bactericidal activities against both cell suspensions and cell cultures of each strain after 5 weeks. No cells were detected in the cell suspensions and cultures when the ACC of WAEW was more than 20 mg/L and treatment time was greater than 15 s. Bactericidal activity of WAEW against V. vulnificus cell culture was reduced when the ACC of WAEW was less than 15 mg/L but was maintained in the V. vulnificus cell suspension when the ACC of WAEW was 0.5 mg/L. Thus, the bactericidal activity of WAEW was primarily affected by ACC rather than treatment time. Similar results were obtained for V. parahaemolyticus, indicating that WAEW kills these microorganisms more quickly than a chemical product such as sodium hypochlorite (NaClO), even at equivalent ACCs.

Differences in fungicidal efficiency against Aspergillus flavus for neutralized and acidic electrolyzed oxidizing waters

Neutralized electrolyzed oxidizing water (NEW) and acidic electrolyzed oxidizing water (AcEW) are electrolyzed oxidizing waters (EOW) that have significantly different fungicidal efficiencies against Aspergillus flavus ( A. flavus) (The actuation durations of no survival population to NEW and AcEW were 90 s and 120 s, respectively.), even when used at the same available chlorine concentration (30 ppm). It has been verified by our previous research. This study hypothesized that this difference did not originate from the structure of water but based on the OH radical ( OH). It was proved by the UV spectroscopy, 17O-NMR spectroscopy and electron spin resonance analysis. NEW contains more OH compared with AcEW in the same available chlorine concentration level. The OH that exists in NEW and AcEW was found to have an important fungicidal factor that destroys the cellular structures of the A. flavus conidia. It also damages the cellular normal function of A. flavus conidia that brought about K + and Mg 2+ leakages. The levels of OH that exist in NEW and AcEW could be the important reason that leads to significant fungicidal efficiencies against A. flavus.

The efficacy of the electrolyzed oxidizing water in the oral irrigation of patients with oral trachea can-nula

Objective To study the efficacy of the electrolyzed oxidizing water (EOW) in the oral irrigation of patients with oral trachea cannula. Methods 60 patients with oral trachea cannula were ran-domly divided into the experimental group and the control group, the experimental group received oral irri-gation with EOW,while the control group used normal saline. The oral irrigation efficacy was compared be-tween the two groups. Results In the experimental group,the bacterial clearance rate was 95.21% ,while the control one's was 37.19%, the stomatodysodia rate of the experimental group was 3.33%, the control one's was 86.60%, the oral fungus infection rate of the experimental group was 0% , the control one's was 43.33%, the incidence of dental ulcer of the experimental group was 10.00%, the control one's was 3.33%. Significant difference existed in bacterial clearance rate and the stomatedysodia rate between the two groups. Conclusions Oral irrigation with EOW in oral trachea cannula patients can decrease or con-trol the field planting of bacterium in pharynx oralis and stomatodysodia, and prevent pulmonary infection. Key words: Electrolyzed oxidizing water; Oral trachea cannula; Oral irrigation

Efficiency of Electrolyzed Oxidizing Water for Inactivation of Salmonella spp. and Inoculated Shell Eggs

The risk of a salmonellosis outbreak from consuming contaminated eggs is a societal and governmental concern. The bactericidal efficiency of electrolyzed oxidizing (EO) water for inactivation of salmonella and artificially inoculated shell eggs were evaluated in this study. The effects of available chlorine concentration (ACC, 0.1-2.0 mg/l) and pH value (2.3, 3.5, 4.6, 5.7 and 6.5) on the bactericidal activity of EO water were investigated by using pure cultures (7.0-8.0 log10 CFU/ml) of Salmonella pullorum and Salmonella enteritidis strains. EO water was effective for inactivation of both pathogens. The bactericidal activity increased with increasing the ACC of EO water. The bacteria were completely inactivated when the ACC of EO water was higher than 1.0 mg/l. At a sufficient ACC (greater than 3.0 mg/l), the bactericidal activity of EO water was independent of its pH value. A 100% inactivation (reduction of 6.7 log10 CFU/g) of both pathogens on the surface of shell eggs was achieved at an ACC of 20 mg/l except for the treatment of EO water spraying. Shell eggs soaked in alkaline electrolyzed water followed by soaked in EO water was more effective to reduce the viable counts of both pathogens compared to EO water used alone. No survival of both pathogens was detected in EO water after washing treatment. Results indicated that EO water is a promising and powerful disinfectant agent for shell eggs washing processing.

Effects of electrolyzed oxidizing water and ice treatments on reducing histamine-producing bacteria on fish skin and food contact surface

This study investigated efficacy of electrolyzed oxidizing water (EO water) and ice (EO ice) treatments in reducing histamine-producing bacteria ( Enterobacter aerogenes, Enterobacter cloacae, Klebsiella pneumoniae, Morganella morganii and Proteus hauseri) on food contact surfaces (ceramic tile and stainless steel) and fish skin (Atlantic salmon and yellowfin tuna). Soaking ceramic tile and stainless steel in EO water (50 ppm chlorine) for 5 min inactivated inoculated bacteria on the surface (>0.92 to >5.4 log CFU/cm 2 reductions). E. cloacae, K. pneumoniae and P. hauseri did not survive well on fish skin. Soaking salmon skin in EO water (100 ppm chlorine) for 120 min resulted in 1.3 and 2.2 log CFU/cm 2 reductions of E. aerogenes and M. morganii, respectively. A treatment of EO ice (100 ppm chlorine) for 24 h was capable of reducing E. aerogenes and M. morganii on tuna skin by 2.4 and 3.5 log CFU/cm 2, respectively. EO water and EO ice can be used as post-harvest treatments for reducing histamine-producing bacteria on food contact surfaces and fish skin.

Spraying hatching eggs with electrolyzed oxidizing water reduces eggshell microbial load without compromising broiler production parameters

An experiment was conducted to determine whether spraying hatching eggs with electrolyzed oxidizing (EO) water would decrease eggshell microbial load and hence improve hatchability, chick quality, and broiler growth performance. Eggs were collected from a broiler breeder flock; half the eggs were sprayed with EO water and the other half were left untreated. Enterobacteriaceae and total aerobic bacteria present on the eggshells of eggs from both treatments were enumerated. The eggs were incubated, and the broiler chicks were grown out to 39 d. Eggshell microbial load was significantly decreased by spraying the eggs with acidic EO water before incubation, with no effect on cuticle structure [as measured by egg weight (moisture) loss], normal embryonic development, and hatchability. Chick quality, as determined by visual assessment and BW at the time of hatch, was also not affected. However, broiler mortality during the first 2 wk of the production period was significantly reduced in the chicks that hatched from eggs sprayed with EO water compared with chicks hatching from control eggs. The ability of EO water to reduce eggshell microbial load without negatively affecting hatchability or chick quality may make it a useful product for hatching egg sanitation.

Effect of decontamination on the microbial load, the sensory quality and the nutrient retention of ready-to-eat white cabbage

The effect of different decontamination treatments such as washing with sodium hypochlorite (20 and 200 mg/L), peroxyacetic acid (80 and 250 mg/L), neutral electrolysed oxidising water (4.9 and 31.7 mg/L free chlorine) and contact with 1.55 mg/L chlorine dioxide gas on the microbial and sensory quality, and the nutrient content of fresh-cut white cabbage was studied. Only rinsing with 200 mg/L sodium hypochlorite, peroxyacetic acid or contact with gaseous chlorine dioxide resulted in significantly higher reductions of the total plate count (1.5–2.5 log cfu/g) than the ones achieved by washing with tap water (0.5 log cfu/g). However, those treatments giving the best results from a microbial point of view induced significant changes in the sensory quality. Regarding the effects on nutrient content, the mechanical effects caused by water washing already reduced the vitamin C content by 16–29%. Contrary to washing with neutral electrolysed oxidising water and contact with chlorine dioxide gas, a supplementary decrease of the vitamin C content ranging between 9 and 28% was observed, when peroxyacetic acid or 200 mg/L sodium hypochlorite were used. After the use of peroxyacetic acid or gaseous chlorine dioxide, the phenol content also showed a decreasing trend, although not statistically significant. Apart from the effect of washing with water, the lipophilic nutrients were well retained after a decontamination step except for the α-tocopherol content, when peroxyacetic acid was used (−43 to 56%), and for the all-trans-β-carotene content (−8%) of cabbage in contact with gaseous chlorine dioxide. Because of its potential to reduce the initial microbial load without negative effects on the sensory quality, in combination with its limited effects on nutrient content, a treatment with 80 mg/L peroxyacetic acid is preferable to decontaminate fresh-cut white cabbage.

Effect of Several Electrolyzed Waters on the Skin Permeation of Lidocaine, Benzoic Acid, and Isosorbide Mononitrate

The effects of several electrolyzed waters were evaluated on the permeation of model base, acid and non-ionized compounds, lidocaine (LC), benzoic acid (BA), and isosorbide mononitrate (ISMN), respectively, through excised hairless rat skin. Strong alkaline-electrolyzed reducing water (ERW) enhanced and suppressed the skin permeation of LC and BA, respectively, and it also increased the skin permeation of ISMN, a non-ionized compound. On the contrary, strong acidic electrolyzed oxidizing water (EOW) enhanced BA permeation, whereas suppressing LC permeation. Only a marginal effect was observed on the skin permeation of ISMN by EOW. These marked enhancing effects of ERW on the skin permeation of LC and ISMN were explained by pH partition hypothesis as well as a decrease in skin impedance. The present results strongly support that electrolyzed waters, ERW and EOW, can be used as a new vehicle in topical pharmaceuticals or cosmetics to modify the skin permeation of drugs without severe skin damage.

Repeated Quick Hot-and-Chilling Treatments for the Inactivation of Escherichia coli O157:H7 in Mung Bean and Radish Seeds

The majority of the seed sprout-related outbreaks have been associated with Escherichia coli O157:H7. Therefore, it is necessary to find an effective method to inactivate these organisms on the seeds prior to sprouting. This study was conducted to assess the effectiveness of repeated quick hot-and-chilling treatments with various chemicals to inactivate E. coli O157:H7 populations inoculated onto mung bean and radish seeds intended for sprout production and to determine the effect of these treatments on seed germination. The treatment time was 20 sec for quick hot and 20 sec for quick chilling in one repeat. Likewise up to five repeats were done throughout the experiments. The chemicals used for this study were electrolyzed acidic (EO) water, phytic acid (0.05%), oxalic acid (3%), surfcera(R), and alpha-torino water(R), and distilled water was used as control. The quick hot treatment was done with 75 degrees C, 70 degrees C, and 60 degrees C, and the chilling temperature was 0 degrees C. The treated seeds were then assessed for the efficacy of this treatment in reducing populations of the pathogens and the effects of repeated quick hot-and-chilling treatments on germination yield. It was found that repeating treatment at 75 degrees C for two or three repeats with phytic acid and oxalic acid could reduce 4.38-log colony-forming unit (CFU)/g of E. coli O157:H7 in mung bean seeds. EO water and distilled water were found equally effective at 75 degrees C for four or five repeats to inactivate E. coli O157:H7 in mung bean seeds. However, alpha-torino water(R) and surfcera(R) were not found effective in comparison to other sanitizers used in this experiment. Irrespective of sanitizer used, the germination yield of the mung bean seed was not affected significantly. On the other hand, distilled water, EO water, and alpha-torino water(R) at 75 degrees C for five repeats were found effective in reducing 5.80-log CFU/g of E. coli O157:H7 in radish seeds; however, the germination yield of the seed was affected significantly. Therefore, repeated quick hot-and-chilling treatments could be useful to decontaminate mung bean seeds intended for sprout production.

Bactericidal Activities of Several Electrolyzed Waters

Bactericidal activities of several electrolyzed waters were evaluated by time-kill assay using Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. Strongly acidic electrolyzed oxidizing water (EOW) showed remarkably high bactericidal activity against all four bacterial strains, including a spore-forming bacterium, B. subtilis. Strongly alkaline electrolyzed reducing water (ERW) exhibited high bactericidal activity against gram-negative bacteria (E. coli and P. aeruginosa), whereas it showed low or no bactericidal activity against gram-positive bacteria. In contrast, hydrogen water (HW) showed only low bactericidal activity against two (S. aureus and P. aeruginosa) of the four strains tested, and weak acidic electrolyzed reducing water (WA-ERW) did not show any bactericidal activity. Thus, it was demonstrated that among several electrolyzed waters, EOW possessed high bactericidal activity against all four bacterial strains regardless of gram-negative or gram-positive status and against their spore formation. It was also suggested that some electrolyzed waters might be applicable as disinfectants or antiseptic agents instead of normal purified water in pharmaceutical preparations or cosmetics.

BACTERICIDAL ACTIVITY OF ELECTROLYZED OXIDIZING WATER ON MEAT AND POULTRY

Electrolyzed oxidizing water (EOW) has potential application as a residue free sanitizing agent for food of animal origin. Meat and poultry were contaminated with microorganism, pathogens or not, and different types of electrolyzed oxidizing water treatement were investigated to evaluate the activity of each of these method. In detail, this study is aiming at evaluating the effectiveness of EOW in reducing microbial count, including total bacterial count, Salmonella Typhimurium, Staphylococcus aureus, Listeria monocytogenes and Escherichia coli on meat and poultry. EOW has a very strong disinfectant activity which, along with its easy and safe use, makes a good alternative to many other more widely used disinfectants.

Impact of decontamination agents and a packaging delay on the respiration rate of fresh-cut produce

Quality of fresh-cut produce is influenced by both microbiological and physiological processes. Up till now there have been only limited reports dealing with the effect of decontamination on the respiration of lightly processed produce. In this paper water, sodium hypochlorite, neutral electrolysed oxidising water and peroxyacetic acid were evaluated for their effect on the respiration rate of fresh-cut vegetables such as carrot, iceberg lettuce, leek and white cabbage. Respiration rate measurements were done at 7 °C and 3% O 2 by means of the closed method. Following that, the influence of a packaging delay on the respiration rate of water washed and treated (80 mg/L peroxyacetic acid) carrot and white cabbage was examined. Sodium hypochlorite did not have a significant influence on the respiration rate of carrot, leek and cabbage, but increased that of iceberg lettuce from 0.30 to 0.46 mmol O 2/kg h. Washing leek and iceberg lettuce with peroxyacetic acid did not change the respiration rate, but decreased that of carrot and white cabbage to a level of less than half of its initial value. Apparently the respiration rate of fresh-cut produce with a large area of cut surfaces, was influenced by peroxyacetic acid decontamination. Grated carrots did not show any significant respiration after a treatment with 250 mg/L peroxyacetic acid. A treatment with neutral electrolysed oxidising water containing 30 mg/L free chlorine decreased the respiration of leek and white cabbage whereas with 5 mg/L it reduced the respiration of white cabbage only. During a packaging delay of 24 or 48 h a sharp increase in respiration of water washed vegetables as well as vegetables treated with peroxyacetic acid was observed. In general, besides the degree of cutting, other processing effects such as the type of sanitizer and the time between processing and packaging can have an influence on the respiration and must be taken into account when an appropriate packaging configuration needs to be designed for a specific commodity.

Ultrasonically nebulised electrolysed oxidising water: a promising new infection control programme for impressions, metals and gypsum casts used in dental hospitals

Controlling the transmission of infectious diseases by impressions, metals and dental casts in dental hospitals remains a challenge. Current disinfection methods have various drawbacks. This study introduced and provided a preliminary evaluation of the feasibility of using ultrasonically nebulised, electrolysed oxidising water (UNEOW) as a new infection control programme. UNEOW was produced from freshly generated electrolysed oxidising water (EOW). Samples of impressions, titanium and gypsum were subjected to the following treatments: (1) immersion in 1% sodium hypochlorite for 10min; (2) immersion in EOW for 10min; (3) exposure to UNEOW for 15, 30 and 45min; (4) no disinfection (control). Bactericidal efficacy was examined using Staphylococcus aureus and Bacillus subtilis var. niger spores as indicators. Dimensional accuracy, surface quality, and effect of corrosion were also evaluated for the different samples. Results showed that except for B. subtilis var. niger spores on gypsum casts, the bacterial reduction log(10) values after 30-45min treatment with UNEOW were all above 4. The impression dimensional changes showed no difference between control and UNEOW groups, but both were significantly lower than the EOW and sodium hypochlorite groups (P<0.05). The same was true for the surface quality of impressions and gypsum casts. No assessable corrosion was found on the titanium surface after a 45min treatment with UNEOW. The findings indicated that use of UNEOW is a feasible and promising approach for controlling the transmission of infectious diseases by impressions, gypsum casts and denture metals in dental facilities.

Antimicrobial Effect of Electrolyzed Oxidizing Water against Escherichia coli O157:H7 and Listeria monocytogenes on Fresh Strawberries (Fragaria×ananassa)

Antibacterial activity of electrolyzed oxidizing (EO) water prepared from 0.05% or 0.10% (w/v) sodium chloride (NaCl) solutions against indigenous bacteria associated with fresh strawberries (Fragaria x ananassa) was evaluated. The efficacy of EO water and sodium hypochlorite (NaOCl) solution in eliminating and controlling the growth of Listeria monocytogenes and Escherichia coli O157:H7 inoculated onto strawberries stored at 4 +/- 1 degrees C up to 15 d was investigated at exposure time of 1, 5, or 10 min. Posttreatment neutralization of fruit surfaces was also determined. More than 2 log(10) CFU/g reductions of aerobic mesophiles were obtained in fruits washed for 10 or 15 min in EO water prepared from 0.10% (w/v) NaCl solution. Bactericidal activity of the disinfectants against L. monocytogenes and E. coli O157:H7 was not affected by posttreatment neutralization, and increasing exposure time did not significantly increase the antibacterial efficacy against both pathogens. While washing fruit surfaces with distilled water resulted in 1.90 and 1.27 log(10) CFU/mL of rinse fluid reduction of L. monocytogenes and E. coli O157:H7, respectively, >/= 2.60 log(10) CFU/mL of rinse fluid reduction of L. monocytogenes and up to 2.35 and 3.12 log(10) CFU/mL of rinse fluid reduction of E. coli O157:H7 were observed on fruit surfaces washed with EO water and NaOCl solution, respectively. Listeria monocytogenes and E. coli O157:H7 populations decreased over storage regardless of prior treatment. However, EO water and aqueous NaOCl did not show higher antimicrobial potential than water treatment during refrigeration storage.

Reduction of bacteria on spinach, lettuce, and surfaces in food service areas using neutral electrolyzed oxidizing water

Food safety issues and increases in food borne illnesses have promulgated the development of new sanitation methods to eliminate pathogenic organisms on foods and surfaces in food service areas. Electrolyzed oxidizing water (EO water) shows promise as an environmentally friendly broad spectrum microbial decontamination agent. EO water is generated by the passage of a dilute salt solution (∼1% NaCl) through an electrochemical cell. This electrolytic process converts chloride ions and water molecules into chlorine oxidants (Cl 2, HOCl/ClO −). At a near-neutral pH (pH 6.3–6.5), the predominant chemical species is the highly biocidal hypochlorous acid species (HOCl) with the oxidation reduction potential (ORP) of the solution ranging from 800 to 900 mV. The biocidal activity of near-neutral EO water was evaluated at 25 °C using pure cultures of Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, Listeria monocytogenes, and Enterococcus faecalis. Treatment of these organisms, in pure culture, with EO water at concentrations of 20, 50, 100, and 120 ppm total residual chlorine (TRC) and 10 min of contact time resulted in 100% inactivation of all five organisms (reduction of 6.1–6.7 log 10 CFU/mL). Spray treatment of surfaces in food service areas with EO water containing 278–310 ppm TRC (pH 6.38) resulted in a 79–100% reduction of microbial growth. Dip (10 min) treatment of spinach at 100 and 120 ppm TRC resulted in a 4.0–5.0 log 10 CFU/mL reduction of bacterial counts for all organisms tested. Dipping (10 min) of lettuce at 100 and 120 ppm TRC reduced bacterial counts of E. coli by 0.24–0.25 log 10 CFU/mL and reduced all other organisms by 2.43–3.81 log 10 CFU/mL.

Shelf-life of minimally processed cabbage treated with neutral electrolysed oxidising water and stored under equilibrium modified atmosphere

Minimally processed vegetables (MPV) have a short shelf-life. Neutral electrolysed oxidising water (NEW) is a novel decontamination method. The objective of this study was to test the potential of NEW to extend the shelf-life of a MPV, namely shredded cabbage. Samples of shredded cabbage were immersed in NEW containing 40 mg/L of free chlorine or tap water (control) up to 5 min, and then stored under equilibrium modified atmosphere at 4 °C and 7 °C. Proliferation of aerobic mesophilic bacteria, psychrotrophic bacteria, lactic acid bacteria and yeasts were studied during the shelf-life. Also pH and sensorial quality of the samples as well as O 2 and CO 2 composition of the headspace of the bags was evaluated. From the microbial groups, only psychrotrophic counts decreased significantly ( P < 0.05) due to the effect of NEW, but the counts in treated samples and controls were similar after 3 days of storage at 4 °C and 7 °C. Packaging configurations kept O 2 concentration around 5% and prevented CO 2 accumulation. pH increased from 6.1–6.2 to 6.4 during the shelf-life. No microbial parameter reached unacceptable counts after 14 days at 4 °C and 8 days of storage at 7 °C. The shelf-life of controls stored at 4 °C was limited to 9 days by overall visual quality (OVQ), while samples treated with NEW remained acceptable during the 14 days of the experiment. The shelf-life of controls stored at 7 °C was limited to 6 days by OVQ and browning, while that of samples treated with NEW were limited to 9 days by OVQ, browning and dryness. According to these results, a shelf-life extension of at least 5 days and 3 days in samples stored respectively at 4 °C and 7 °C can be achieved by treating shredded cabbage with NEW. NEW seems to be a promising method to prolong the shelf-life of MPV.

Spoilage Microflora of Broiler Carcasses Washed with Electrolyzed Oxidizing or Chlorinated Water Using an Inside-Outside Bird Washer

The effect of acidic, electrolyzed oxidizing (EO) water and chlorinated water on the spoilage microflora of processed broiler carcasses was examined. Carcasses were sprayed for 5 s at 80 psi with tap, chlorinated, or EO water in an inside-outside bird washer. Treated carcasses were then stored at 4 degrees C for 0, 3, 7, or 14 d, and the microbial flora of the carcasses was sampled using the whole-carcass rinse procedure. Populations of psychrotrophic bacteria and yeasts in the carcass rinsates were enumerated. Results indicated that immediately after spraying the carcasses, significantly fewer psychrotrophic bacteria were recovered from carcasses sprayed with chlorinated or EO water than from carcasses sprayed with tap water. Furthermore, significantly fewer yeasts were recovered from carcasses sprayed with EO water than from carcasses sprayed with tap or chlorinated water. The population of psychrotrophic bacteria and yeasts increased on all carcasses during refrigerated storage. However, after 14 d of storage, significantly fewer psychrotrophic bacteria and yeasts were recovered from carcasses sprayed with EO water than from carcasses sprayed with tap or chlorinated water, and significantly fewer microorganisms were recovered from carcasses sprayed with chlorinated water than from carcasses sprayed with tap water. Pseudomonas spp. and Candida spp. were the primary microbial isolates recovered from the broiler carcasses. Findings from the present study indicate that EO water can effectively be used in inside-outside bird washers to decrease the population of spoilage bacteria and yeasts on processed broiler carcasses.

The economics of reducing campylobacter in the Belgian poultry meat chain

Campylobacter infections are a serious public health problem in Belgium. Poultry meat is most likely responsible for 40% of human campylobacteriosis cases in Belgium. On a yearly basis, consumption of poultry meat causes at least 22,000 campylobacteriosis cases with a costs-of-illness of ?11 million. This study aims to evaluate the efficiency, i.e. the ratio of reduced costs-of-illness on intervention costs, of various intervention measures. These measures were selected by representatives from the poultry meat sector and experts in the field. The selection comprised measures at farm level (administration of bacteriocins to feed of broilers shortly before slaughter), at the processing plant (spraying of carcasses with lactic acid or electrolyzed oxidizing (EO) water, crust-freezing or irradiation of carcasses and chicken filets at the end of the slaughterline) and at consumer level (improving kitchen hygiene and application of home-freezing). Among these measures, the decontamination of carcasses with EO water is the most efficient. Administration of bacteriocins to feed of broilers is also efficient. Irradiation is the most effective intervention, however, one of the least efficient. There seems to be less gain by trying to improve food handling in the kitchen. The cost to reach consumers is large while only a very limited fraction of the consumers is willing to change their behavior.

Effects of Electrolyzed Oxidizing Water Treatment on Reducing Vibrio parahaemolyticus and Vibrio vulnificus in Raw Oysters

Contamination of Vibrio parahaemolyticus and Vibrio vulnificus in oysters is a food safety concern. This study investigated effects of electrolyzed oxidizing (EO) water treatment on reducing V. parahaemolyticus and V. vulnificus in laboratory-contaminated oysters. EO water exhibited strong antibacterial activity against V. parahaemolyticus and V. vulnificus in pure cultures. Populations of V. parahaemolyticus (8.74 × 107 CFU/ml) and V. vulnificus (8.69 × 107 CFU/ml) decreased quickly in EO water containing 0.5% NaCl to nondetectable levels (>6.6 log reductions) within 15 s. Freshly harvested Pacific oysters were inoculated with a five-strain cocktail of V. parahaemolyticus or V. vulnificus at levels of 104 and 106 most probable number (MPN)/g and treated with EO water (chlorine, 30 ppm; pH 2.82; oxidation-reduction potential, 1131 mV) containing 1% NaCl at room temperature. Reductions of V. parahaemolyticus and V. vulnificus in oysters were determined at 0 (before treatment), 2, 4, 6, and8hof treatment. Holding oysters inoculated with V. parahaemolyticus or V. vulnificus in the EO water containing 1% NaCl for 4 to 6 h resulted in significant (P < 0.05) reductions of V. parahaemolyticus and V. vulnificus by 1.13 and 1.05 log MPN/g, respectively. Extended exposure (>12 h) of oysters in EO water containing high levels of chlorine (>30 ppm) was found to be detrimental to oysters. EO water could be used as a postharvest treatment to reduce Vibrio contamination in oysters. However, treatment should be limited to 4 to6hto avoid death of oysters. Further studies are needed to determine effects of EO water treatment on sensory characteristics of oysters.

Susceptibility of Penicillium expansum Spores to Sodium Hypochlorite, Electrolyzed Oxidizing Water, and Chlorine Dioxide Solutions Modified with Nonionic Surfactants

The use of water flotation tanks during apple packing increases the risk of contamination of apples by spores of Penicillium expansum, which may accumulate in the recirculating water. Routine addition of sanitizers to the water may prevent such contamination. Sodium hypochlorite (NaOCl), chlorine dioxide (ClO2), and electrolyzed oxidizing (EO) water have varied activity against spores of P. expansum, and their effectiveness could be enhanced using surfactants. The objective of this study was to determine the ability of three nonionic surfactants, polyoxyethylene sorbitan monooleate (Tween 80), polyoxyethylene sorbitan monolaurate (Tween 20), and sorbitan monolaurate (Span 20), to enhance the efficacy of NaOCl, ClO2, and EO water against spores of P. expansum in aqueous suspension at various temperatures and pH conditions. The efficacy of NaOCl solutions was enhanced by the addition of surfactants at both pH 6.3 and pH 8 (up to 5 log CFU reduction). EO water and ClO2 were effective against P. expansum spores (up to 5 log CFU and 4 log CFU reduction, respectively), but addition of surfactants was not beneficial. All solutions were less effective at 4°C compared to 24°C irrespective of the presence of surfactants. Nonionic surfactants could potentially be used with NaOCl to improve control of P. expansum in flotation tanks, but the efficacy of such formulations should be validated under apple packing conditions.