• Food Science and Preservation
• /
• v.18 no.3
• /
• pp.423-428
• /
• 2011

Inactivation kinetic data of Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus, Salmonella Typhimurium, and Salmonella Enteritidis via treatment with aqueous chlorine dioxide treatment at a specific concentration were evaluated using the first-order kinetic and Weibull models. The Weibull model showed a better fit with the kinetic data than the first-order kinetic model. The survival curves after the aqueous chlorine dioxide treatment showed $t_R$ values(time required to reduce microbial populations by 90%) of 2.49 min for E. coli O157:H7 at 5 ppm, 1.47 min for L. monocytogenes at 5 ppm, 0.94 min for S. aureus at 5 ppm, 0.87 min for S. Typhimurium at 1 ppm, and 0.08 min for S. Enteritidis at 1 ppm, according to the Weibull model.

• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.4
• /
• pp.560-564
• /
• 2012

This study was undertaken to assess the microbiological quality and prevalence of pathogens in organic vegetables produced in Korea. A total of 189 organically grown vegetable samples (perilla leaf 50, lettuce 50, tomato 39, cucumber 50) were analyzed for the presence of aerobic plate count, Escherichia coli O157:H7, Salmonella spp., Staphylococcus aureus, Listeria monocytogenes, and Yersinia enterocolitica. The total aerobic plate counts were in the range of 4.2 to $7.7log\;CFU\;g^{-1}$ for perilla leaf, 5.0 to $8.0log\;CFU\;g^{-1}$ for lettuce, 4.0 to $7.5log\;CFU\;g^{-1}$ for tomato, and 6.6 to $8.6log\;CFU\;g^{-1}$ for cucumber. The highest counts were found in cucumber. E. coli O157:H7, Salmonella spp., S. aureus, L. monocytogenes, and Y. enterocolitica were not detected from any organically grown vegetable samples. This research suggests that continuous monitoring in organic vegetables is required to improve fresh produce safety.

• Journal of the East Asian Society of Dietary Life
• /
• v.22 no.5
• /
• pp.692-700
• /
• 2012

The antibacterial activity of the ethanol extract of Cornus officinalis against some bacteria related to foodborne illness and food spoilage was investigated. In the case of the disc diffusion assay, clear zones due to the inhibition of proliferation by Cornus officinalis extract were 8.5~18.3 mm at $4,000{\mu}g/disc$. The inhibitory effect of Cornus officinalis was as follows: Escherichia. coli ${\geq}$ Listeria monocytogenes ${\geq}$ E. coli O157:H7 > Bacillus cereus > Staphylococcus aureus > Pseudomonas aeruginosa > Salmonella typhimurium. In addition, the MIC of Cornus officinalis extract toward B. cereus was the lowest at 1,000 ppm. The extract inhibited the growth of E. coli, L. monocytogenes, E. coli O157:H7, and Bacillus cereus throughout the growth stage. However, the growth of P. aeruginosa, S. aureus, and S. typhimurium was only inhibited by the extract during the lag phase. The constituents of all cells tested were released, especially E. coli and E. coli O157:H7. Observation of the cells using SEM demonstrated a morphological change and disruption of cells in response to treatment with Cornus officinalis extract. Based on these findings, the ethanol extracts of Cornus officinalis showed strong antimicrobial activity against all tested bacteria, indicating that Cornus officinalis can be a useful natural antimicrobial reagent.

• Food Science and Biotechnology
• /
• v.17 no.6
• /
• pp.1203-1206
• /
• 2008

Silk fibroin (SF) film containing catechin was prepared and the antimicrobial activity as well as physical property of the film was examined. Tensile strength of the SF film decreased with increasing concentration of catechin, and water vapor permeability of the film decreased. The film's antimicrobial activity against Escherichia coli O157:H7 increased with increasing catechin concentration. Sausage samples were inoculated with E. coli 0157:H7 and Listeria monocytogenes, and the sausage packaged with the SF film containing catechin had a decrease in the populations of E. coli O157:H7 and L. monocytogenes by 0.83 and 0.85 log CFU/g after 12 days of storage, respectively, compared to the control. In addition, the sausage had a better quality than the control regarding lipid oxidation. Our results indicate that sausages can be packed with the SF film containing catechin to extend shelf life.

• the MEAT Journal
• /
• s.35 winter
• /
• pp.34-45
• /
• 2008

People can be exposed to various microorganisms when they eat yukae (seasoned raw meat) because yukae is eaten raw. The purpose of this study was to find out microbial distribution in yukae. In this experiment, 5 restaurants serving yukae were chosen in Daegu area. Mesophilic microorganisms and coliforms were measured by Korean Food Standards Codex. Analyses of Salmonella spp., Listeria monocytogenes, Staphylococcus aureus and Escherichia coli O157:H7 were conducted. As results, mesophilic microorganisms ranged 6.6$\times$103-2.7$\times$105 CFU/g and coliforms ranged 8.9$\times$101-2.1$\times$105 CFU/g. Salmonella spp., Listeria monocytogenes and Escherichia coli O157:H7 were not detected in all 5 samples. However, Staphylococcus aureus was detected in 1 sample out of 5 samples. Hygiene practice during production, processing and cooking process is required.

• Food Science of Animal Resources
• /
• v.27 no.2
• /
• pp.197-202
• /
• 2007

People can be exposed to various microorganisms when they eat yukae(seasoned raw meat) because yukae is eaten raw. The purpose of this study was to find out microbial distribution in yukae. In this experiment, 5 restaurants serving yukae were chosen in Daegu area. Mesophilic microorganisms and coliforms were measured by Korean Food Standards Codex. Analyses of Salmonella spp., Listeria monocytogenes, Staphylococcus aureus and Escherichia coli O157:H7 were conducted. As results, mesophilic microorganisms ranged $6.6{\times}10^3-2.7{\times}10^5\;CFU/g$ and coliforms ranged $8.9{\times}10^1-2.1{\times}10^5CFU/g$. Salmonella spp., Listeria monocytogenes and Escherichia coli O157:H7 were not detected in all 5 samples. However, Staphylococcus aureus was detected in 1 sample out of 5 samples. Hygiene practice during production, processing and cooking process is required.

• Preventive Nutrition and Food Science
• /
• v.13 no.4
• /
• pp.370-374
• /
• 2008

The Gelidium corneum (GC)-whey protein isolate (WPI) blend film containing grapefruit seed extract (GSE) was prepared by incorporating different amounts (0, 0.02, 0.04, 0.08, 0.1%) of GSE into the film. The film's tensile strength (TS) and water vapor permeability (WVP) were improved by the addition of GSE. The film containing 0.1% GSE had a TS of 3.27 MPa, whereas the control had 2.64 MPa. WVP of the film was also significantly decreased by the addition of GSE. Addition of 0.1% GSE decreased the populations of Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Typhimurium by 1.0, 1.6, and 0.6 log CFU/g, respectively, compared to the control. Fish paste was packed with the GC-WPI blend film containing GSE, and microbial change in the fish paste inoculated with E. coli O157:H7, L. monocytogenes, and S. Typhimurium during storage was examined. Populations of E. coli O157:H7, L. monocytogenes, and S. Typhimurium were decreased by 0.60, 0.48, and 0.85 log CFU/g, after 7 day of storage, respectively. These results suggest packaging fish paste in the GC-WPI blend film containing GSE can extend the shelf life.

• Preventive Nutrition and Food Science
• /
• v.15 no.3
• /
• pp.239-243
• /
• 2010

The antimicrobial effects of a commercially available, buffered sodium citrate (BSC) were evaluated for the reduction of total aerobic bacteria count, Salmonella Typhimurium, Escherichia coli O157:H7, Listeria monocytogenes and Staphylococcus aureus in a liquid medium and ground beef. BSC at 0, 1, 2 and 4.8% (wt/vol) or 0, 3, and 4.8% (wt/wt) was mixed into inoculated brain heart infusion (BHI) broth and ground beef (80% lean), respectively. BSC at concentrations of 1 and 2% did not inhibit growth of the pathogens tested in BHI broth. E. coli O157:H7 in BHI broth with 4.8% BSC was significantly reduced (p<0.05) by 3～4 log CFU/mL compared with the control for up to 4 days. At 4.8%, BSC treatment of ground beef most significantly reduced (p<0.05) total aerobic count and E. coli O157:H7 by 2.1 and 2.0 log CFU/g, respectively. This study indicates that the legally allowable level of 1.3% (wt/wt) BSC is not effective for reducing the pathogens tested in ground beef stored at $7^{\circ}C$.

• Korean Journal of Food Science and Technology
• /
• v.37 no.2
• /
• pp.287-293
• /
• 2005

Microbial contamination levels in commercial strawberry juices were examined for sanitary indication bacteria, such as aerobic plate count (APC), coliforms, and Escherchia coli, and pathogenic bacteria such as E. coli O157:H7, Salmonella spp., Staphylococcus aureus, and Listeria monocytogenes. APC and coliform count ranged 0-5.2 and $0-2.8\;log_{10}\;CFU/(mL,\;g,\;100cm^{2},\;hand)$, respectively, and 80% strawberry juices were contaminated with E. coli and S. aureus, detected at 19%, was found in employee's hands, strawberries, and strawberry juices, whereas E. coli O157:H7, Salmonella spp, and L. monocytogenes were not detected. These results will provide microbiological information for introduction of Hazard Analysis Critical Control Point (HACCP) system in juice shops.

• Korean Journal of Food Science and Technology
• /
• v.51 no.6
• /
• pp.604-609
• /
• 2019

To control pathogenic E. coli in biofilm, bacteriophages were isolated from environmental samples. Seventeen isolates had depolymerase activities by translucent zones at the rims of plaques. To determine biofilm-forming ability, an abiotic plastic surface of polystyrene was used; E. coli O103 showed the highest biofilm formation at 30℃ after 24 h. Moreover, biofilm by E. coli O103 on the biotic surface of lettuce was observed by a scanning electron microscope. The bacteriophage cocktail of ΦNOECP40 and ΦNOECP44 showing depolymerase activities was prepared to eliminate the E. coli inbiofilm. By organic acids, reduction of E. coli in biofilm was insignificant and almost undetectable. However, the abundance of E. coli in biofilm was reduced by 3 log CFU/mL from 7.3 log CFU/mL after 60 min with the bacteriophage cocktail. Therefore, we suggest that bacteriophages with depolymerase could be utilized to effectively control pathogenic E. coli in biofilm.