Does electrolyzed water have different sanitizing effects than sodium hypochlorite on different vegetable types?

2017 ◽  
Vol 119 (2) ◽  
pp. 342-356 ◽  
Author(s):  
Se-Young Ju ◽  
Jin-Ju Ko ◽  
Hee-Sun Yoon ◽  
Su-Jin Seon ◽  
Yu-Ri Yoon ◽  
...  
Keyword(s):  
Sodium Hypochlorite ◽  
Microbial Reduction ◽  
Plate Count ◽  
Bacterial Reduction ◽  
Electrolyzed Water ◽  
Content Type ◽  
E Coli ◽  
Washing Method ◽  
Spring Onion ◽  
Fresh Cut

Purpose The purpose of this paper is to examine the efficacy of microbial elimination using different sanitizers in raw vegetables (cherry tomatoes, spring onions, Chinese chives, and chicory) and to analyze the efficacy of Escherichia coli O157:H7 reduction by type of sanitizer and vegetable. Design/methodology/approach To assess the sanitizing effects of microbial elimination by variety of vegetable, the samples were grouped into four different washing methods: control (no sanitizer), 100 ppm chlorine, 100 ppm electrolyzed water, and 200 ppm electrolyzed water after prewashing. Subsequently, quantitative microbiological experiments were conducted to assess aerobic mesophilic plate count (APC), coliform, E. coli, and Bacillus cereus, and sensory changes of the sanitized vegetables were tested. Thereafter, measurement of the sanitizing effects on bacterial reduction after inoculation with E. coli O157:H7 was conducted. Findings The microbial levels of four types of vegetables ranged from 3.37 to 5.24 log CFU/g for APC, 2.41 to 5.57 log CFU/g for E. coli, 0.25 to 5.40 log CFU/g for coliform, and 0.83 to 5.44 log CFU/g for B. cereus. After three types of sanitizing treatments, microbial reduction effects showed 0.94-1.84 log CFU/g for APC, 0.56-1.00 log CFU/g for E. coli, 0.18-1.26 log CFU/g for coliform, and 0.56-1.23 log CFU/g for B. cereus (p<0.05). In sensory evaluation, there were no significant differences in taste and flavor between with and without sanitizing treatments. Regarding bacterial reduction after inoculation with E. coli O157:H7, the microbial reduction on vegetables was shown to be in the range of 0.27-1.57 log CFU/g with 100 ppm sodium hypochlorite, 0.66-3.07 log CFU/g with 100 ppm electrolyzed water, and 0.79-2.55 log CFU/g with 200 ppm electrolyzed water. Chicory, cherry tomato, and spring onion showed significant reduction levels of E. coli O157:H7 after sanitation (p<0.05). Originality/value This study revealed that different sanitization methods are required for different types of vegetables. Electrolyzed water treatment (100 ppm) is a more effective and safe method of washing raw vegetables. Given that the main purpose of sanitizing fresh-cut produce is to maximally reduce microorganism levels, different methods of sanitizing fresh-cut produce with an adequate washing method should be used according to vegetable type.

Decontamination Efficiency of Slightly Acidic Electrolyzed Water on Fresh-Cut Cucumbers

2011 ◽  
Vol 7 (5) ◽  
Author(s):  
Zhuqing Liu ◽  
Yu Dong ◽  
Wenshan Jiang
Keyword(s):  
Sodium Hypochlorite ◽  
Ph Value ◽  
Tap Water ◽  
Aerobic Bacteria ◽  
Sodium Hypochlorite Solution ◽  
Alternative Technique ◽  
Electrolyzed Water ◽  
Hypochlorite Solution ◽  
Microbial Counts ◽  
Fresh Cut

The efficacy of slightly acidic electrolyzed water (SAEW, 20 mg/l of available chlorine) and sodium hypochlorite solution (NaClO, 120 mg/l of available chlorine) used as potential sanitizers for fresh-cut cucumbers was evaluated. SAEW with a near-neutral pH value (5.0 to 6.5) and lower available chlorine concentration (ACC) had an equivalent or higher efficiency to reduce microbial counts on the cucumbers compared to NaClO solution. A 5-minute treatment of SAEW and NaClO solution significantly reduced the indigenous aerobic bacteria on cucumbers by 1.62 and 1.51 log10 CFU/g, and molds and yeasts by 1.35 and 1.12 log10 CFU/g, respectively (P < 0.05). The reduction of microbial counts on cucumbers by tap water was markedly less than that by SAEW and NaClO solution (P < 0.05). Results indicate that SAEW provides an alternative technique for sanitization of fresh-cut vegetables with environmentally friendly broad spectrum microbial decontamination.

scholarly journals Fluorescence Assay for Evaluating Microbicidal Activity of Hand Antiseptics

2015 ◽  
Vol 81 (21) ◽  
pp. 7443-7447
Author(s):  
Rosa M. Lopez-Gigosos ◽  
Alberto Mariscal ◽  
Eloisa Mariscal-Lopez ◽  
Mario Gutierrez-Bedmar ◽  
Joaquin Fernandez
Keyword(s):  
Plate Count ◽  
Content Type ◽  
E Coli ◽  
Glucuronidase Activity ◽  
Count Method ◽  
Fluorescence Methods ◽  
Fluorescence Level ◽  
Assay Time ◽  
Plate Count Method ◽  
Time Required

ABSTRACTWe developed a fluorescent β-d-glucuronidase activity (BGA)-based assay for detecting and quantifyingEscherichia coliin samples to assess the biocide efficacy of hand antiseptics. The fluorescence level is proportional to the number of viableE. coliorganisms present. We compared our assay results to those of theE. coliplate count method specified by the European standard for testing hygienic hand rub disinfectant products (EN1500). The plate count method requires excessive handling and materials and is not valid if the number of organisms per plate is too low or high for counting in many of the samples. We optimized the fluorescent assay based on the cleavage of 4-methylumbelliferyl-β-d-glucuronide by adding 4-nitrophenyl-β-d-glucuronide, a nonfluorogenic BGA substrate, to induce glucuronidase activity and reduce assay time. Furthermore, our method can be automated and eliminates the need for multiple dilutions. Fluorescence was temporally monitored, and the time required to reach a specific value of fluorescence was correlated with the initial number of viableE. coliorganisms on the samples. There was a positive correlation (P< 0.05) with a high correlation coefficient (R2= 0.82) between theE. colicounts by plate count and fluorescence methods. Reported effects in fluorescent BGA were compared to the EN1500 plate count method with five hand disinfectants. We found our method more advantageous, because it was as sensitive as the EN1500 method, requires less time to complete, and is less expensive and less laborious than conventional plating techniques.

scholarly journals Physical Covering for Control of Escherichia coli O157:H7 and Salmonella spp. in Static and Windrow Composting Processes

2015 ◽  
Vol 81 (6) ◽  
pp. 2063-2074 ◽  
Author(s):  
Jitendra R. Patel ◽  
Irene Yossa ◽  
Dumitru Macarisin ◽  
Patricia Millner
Keyword(s):  
Escherichia Coli ◽  
Escherichia Coli O157 ◽  
Bacterial Reduction ◽  
Salmonella Spp ◽  
Rapid Reduction ◽  
Content Type ◽  
E Coli ◽  
Windrow Composting ◽  
Composting Systems ◽  
Feedstock Material

ABSTRACTThis study investigated the effect of a 30-cm covering of finished compost (FC) on survival ofEscherichia coliO157:H7 andSalmonellaspp. in active static and windrow composting systems. Feedstocks inoculated withE. coliO157:H7 (7.41 log CFU/g) andSalmonella(6.46 log CFU/g) were placed in biosentry tubes (7.5-cm diameter, 30-cm height) at three locations: (i and ii) two opposing sides at the interface between the FC cover layer (where present) and the feedstock material (each positioned approximately 10 cm below the pile's surface) and (iii) an internal location (top) (approximately 30 cm below the surface). On specific sampling days, surviving populations of inoculatedE. coliO157:H7 andSalmonella, genericE. coli, and coliforms in compost samples were determined.Salmonellaspp. were reduced significantly within 24 h in windrow piles and were below the detection limit after 3 and 7 days at internal locations of windrow and static piles containing FC covering, respectively. Likewise,E. coliO157:H7 was undetectable after 1 day in windrow piles covered with finished compost. Use of FC as a covering layer significantly increased the number of days that temperatures in the windrows remained ≥55°C at all locations and in static piles at internal locations. These time-temperature exposures resulted in rapid reduction of inoculated pathogens, and the rate of bacterial reduction was rapid in windrow piles. The sample location significantly influenced the survival of these pathogens at internal locations compared to that at interface locations of piles. Finished compost covering of compost piles aids in the reduction of pathogens during the composting process.

The effect of different ultraviolet-C light doses on microbial reduction and the components of camel milk

2020 ◽  
pp. 108201322093523
Author(s):  
Namariq Dhahir ◽  
Jean Feugang ◽  
Katherine Witrick ◽  
Seongbin Park ◽  
Shecoya White ◽  
...  
Keyword(s):  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Microbial Reduction ◽  
Camel Milk ◽  
Plate Count ◽  
Thiobarbituric Acid Reactive Substance ◽  
E Coli ◽  
Milk Samples ◽  
Milk Components ◽  
Ultraviolet C

As a result of increasing interest in non-thermal technologies as a possible alternative or complementary to milk pasteurization processing, the objectives of this study were to determine the effects of different ultraviolet-C light doses on the viability of Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium and chemical changes to camel milk components. Pasteurized and inoculated camel milk samples were ultraviolet-C treated in a continuous flow system. The viability of E. coli O157:H7 and S. Typhimurium was evaluated with both in vivo imaging system and traditional plate count agar method. Samples subjected to the 4.15, 8.30, and 12.45 mJ/cm2 of ultraviolet-C treatment resulted in 1.9, 3.3, and 3.9-log reductions in E. coli O157:H7 and 0.9, 3, and 3.9-log reductions in S. Typhimurium, respectively. The measurement of secondary lipid peroxidation products (or ThioBarbituric Acid Reactive Substance values) showed no significant (P > 0.05) differences between the raw and ultraviolet-C treated milk samples. Additionally, no changes (P > 0.05) in the protein profiles of αs1-casein, α-lactalbumin, and lactoferrin were observed between both samples. Compared to the untreated raw milk, c9 t11 conjugated linoleic acid decreased (P < 0.01) while t10 c12 conjugated linoleic acid increased (P < 0.01) in the ultraviolet-C treated milk. Furthermore, three new volatile compounds were identified in the ultraviolet-C treated milk compared to the control. In conclusion, milk treated with the ultraviolet-C light at a dose of 12.45 mJ/cm2 did not meet the Food and Drug Administration (FDA) requirements for the 5-log pathogen reduction. The ultraviolet-C treatment, on the other hand, had minimal effects on camel milk components.

scholarly journals Seasonal Prevalence of Shiga Toxin-Producing Escherichia coli on Pork Carcasses for Three Steps of the Harvest Process at Two Commercial Processing Plants in the United States

2020 ◽  
Vol 87 (1) ◽  
Author(s):  
Ivan Nastasijevic ◽  
John W. Schmidt ◽  
Marija Boskovic ◽  
Milica Glisic ◽  
Norasak Kalchayanand ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Severe Disease ◽  
Control Point ◽  
The United States ◽  
Plate Count ◽  
Seasonal Effect ◽  
Content Type ◽  
E Coli ◽  
Pork Products

ABSTRACT Shiga toxin-producing Escherichia coli (STEC) is a foodborne pathogen that has a significant impact on public health, with strains possessing the attachment factor intimin referred to as enterohemorrhagic E. coli (EHEC) and associated with life-threatening illnesses. Cattle and beef are considered typical sources of STEC, but their presence in pork products is a growing concern. Therefore, carcasses (n = 1,536) at two U.S. pork processors were sampled once per season at three stages of harvest (poststunning skins, postscald carcasses, and chilled carcasses) and then examined using PCR for Shiga toxin genes (stx), intimin genes (eae), aerobic plate count (APC), and Enterobacteriaceae counts (EBC). The prevalence of stx on skins, postscald, and chilled carcasses was 85.3, 17.5, and 5.4%, respectively, with 82.3, 7.8, and 1.7% of swabs, respectively, having stx and eae present. All stx-positive samples were subjected to culture isolation that resulted in 368 STEC and 46 EHEC isolates. The most frequently identified STEC were serogroups O121, O8, and O91 (63, 6.7, and 6.0% of total STEC, respectively). The most frequently isolated EHEC was serotype O157:H7 (63% of total EHEC). Results showed that scalding significantly reduced (P < 0.05) carcass APC and EBC by 3.00- and 2.50-log10 CFU/100 cm2, respectively. A seasonal effect was observed, with STEC prevalence lower (P < 0.05) in winter. The data from this study show significant (P < 0.05) reduction in the incidence of STEC (stx) from 85.3% to 5.4% and of EHEC (stx plus eae) from 82.3% to 1.7% within the slaughter-to-chilling continuum, respectively, and that potential EHEC can be confirmed present throughout using culture isolation. IMPORTANCE Seven serogroups of STEC are responsible for most (>75%) cases of severe illnesses caused by STEC and are considered adulterants of beef. However, some STEC outbreaks have been attributed to pork products, although the same E. coli are not considered adulterants in pork because little is known of their prevalence along the pork chain. The significance of the work presented here is that it identifies disease-causing STEC, EHEC, demonstrating that these same organisms are a food safety hazard in pork as well as beef. The results show that most STEC isolated from pork are not likely to cause severe disease in humans and that processes used in pork harvest, such as scalding, offer a significant control point to reduce contamination. The results will assist the pork processing industry and regulatory agencies to optimize interventions to improve the safety of pork products.

scholarly journals Control Measures of Pathogenic Microorganisms and Shelf-Life Extension of Fresh-Cut Vegetables

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 655
Author(s):  
Jeong Yeon Lee ◽  
So Young Yang ◽  
Ki Sun Yoon
Keyword(s):  
Shelf Life ◽  
Combined Treatment ◽  
Microbial Reduction ◽  
Control Measures ◽  
Life Extension ◽  
Quality Properties ◽  
E Coli ◽  
Fresh Cut ◽  
Reduction Effect ◽  
Uv C

We investigated the combined effect of using slightly acidic electrolyzed water (SAEW), ultrasounds (US), and ultraviolet-C light-emitting diodes (UV-C LED; 275 nm) for decreasing pathogenic Escherichia coli and Staphylococcus aureus (SEA) in fresh-cut vegetables, including carrots, celery, paprika, and cabbage. Survival of pathogenic E. coli and SEA and quality properties of fresh-cut vegetables at 5 and 15 °C for 7 days were also investigated. When combined treatment (SAEW + US + UV-C LED) was applied to fresh-cut vegetables for 3 min, its microbial reduction effect was significantly higher (0.97~2.17 log CFU/g) than a single treatment (p < 0.05). Overall, the reduction effect was more significant for SEA than for pathogenic E. coli. At 5 °C, SAEW + US and SAEW + US + UV-C LED treatments reduced populations of pathogenic E. coli and SEA in all vegetables. At 15 °C, SAEW + US + UV-C LED treatment inhibited the growth of both pathogens in carrot and celery and extended the shelf life of fresh-cut vegetables by preventing color changes in all vegetables. Although the effects of treatments varied depending on the characteristics of the vegetables and pathogens, UV-C LED can be suggested as a new hurdle technology in fresh-cut vegetable industry.

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