• Journal of Food Hygiene and Safety
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• v.34 no.2
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• pp.170-177
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• 2019

The aim of this study was to investigate the effect of different concentrations of chlorine dioxide ($ClO_2$) on sterilization and deodorization of food-holding cabinets under different exposure times. For the measuring sterilization and deodorization, a 6.5 L chamber and a 625 L cabinet with circulation systems were used. Two bacteria (Staphylococcus aureus KCTC1916 and Escherichia coli KCTC 1682) that were artificially inoculated in the plate respectively were put into the 6.5 L chamber and the 625 L cabinet. The $ClO_2$ gas was produced by ampules. In the 6.5 L chamber, neither of the two bacteria was detected after 24 hours treatment by $ClO_2$ gas. Moreover, the deodorization rate against ammonia and phenol was 94% and 70%, respectively, but deodorization against formaldehyde was not effective. When the concentration reached maximum (6 ampule, 4.6 ppm) levels in the cabinet, it lasted for approximately 2 h and then decreased slowly. When a circulator was used, the gas concentration was very low (6 ampule, 0.8 ppm) and the antibacterial activity against S. aureus and E. coli was low. The level of reduction against S. aureus and E. coli was 2.98 log CFU/plate and 6.06 log CFU/plate, respectively, in the cabinet after 24 h without a circulator. The reduction against S. aureus KCTC1916 and E. coli KCTC1682 was 2.69 log CFU/plate and 4.41 log CFU/plate for 24 h, respectively.

• Journal of Food Hygiene and Safety
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• v.33 no.4
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• pp.255-258
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• 2018

The objective of this study was to investigate the inhibitory effect of natural antimicrobials on Listeria monocytogenes isolated from Korean slaughterhouses. A mixture of 15 strains of L. monocytogenes at low (3 Log CFU/mL) or high (7 Log CFU/mL) concentration was exposed to various extracts (grapefruit seed extract, citrus fruit extract, ginger extract, pear extract, Japanese apricot concentrate, balloon flower extract, jujube extract, and omija extract) at $0.001-4.0{\mu}g/mL$. Ginger extract, pear extract, Japanese apricot concentrate, balloon flower extract, jujube extract, or omija extract showed no antimicrobial effects on high-concentration of L. monocytogenes (7 Log CFU/mL). However, grapefruit seed extract and citrus fruit extract showed antibacterial effects against L. monocytogenes at 3 and 7 Log CFU/mL with MBCs of 0.001 and $0.002{\mu}g/mL$, respectively. These results indicate that grapefruit seed extract and citrus fruits extract can be used to control L. monocytogenes as natural antimicrobials.

• The Korean Journal of Food And Nutrition
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• v.28 no.5
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• pp.918-925
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• 2015

An investigation was conducted to evaluate the hygienic status of 33 high school foodservice systems in Yongin city by using hygiene management guide checklist, ATP bioluminescence assay and microbe inspection petrifilm (APC, coliform group, Staphylococcus aureus) of food utensils during use. The 22 hygiene management guide checklist items about facilities, personal hygiene, food control, distribution, washing and disinfection had good grade but there were some inadequate behaviors on observation. The inspection results showed their sanitary condition met the level B of the recommendation of Korea method, it means sanitary management system get settled but more practical CCP system was needed. ATP bioluminescence assay was conducted on surface of food facilities, ATP ranged 425~2,552 RLU on gloves, 541~70,251 RLU on apron, 1,596~88,490 RLU on working desk, 1,177~263,813 RLU on sterilizer grip, 715~32,814 RLU on sterilizer shelf, 114~619,725 RLU on refrigerator grip, 677~319,007 RLU on refrigerator shelf, 71~196,725 RLU on freezer grip, 1,535~233,375 RLU on freezer shelf. APC ranged $66.7{\pm}29.0CFU$ on freezer grip, $102.1{\pm}35.9CFU$ on refrigerator grip, $45.4{\pm}28.2CFU$ on heating cabinet grip, $58.8{\pm}40.4CFU$ on sterilizer grip, the number of coliform group ranged $5.6{\pm}4.9CFU$ on freezer grip, $9.1{\pm}8.7CFU$ on refrigerator grip, $1.2{\pm}1.1CFU$ on heating cabinet grip, $4.5{\pm}4.4CFU$ on sterilizer grip. S. aureus ranged $8.0{\pm}5.6CFU$ on freezer grip, $12.2{\pm}9.6CFU$ on refrigerator grip, $2.1{\pm}1.6CFU$ on heating cabinet grip, $11.6{\pm}6.4CFU$ on sterilizer grip.

• Korean Journal of Food Science and Technology
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• v.37 no.1
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• pp.122-128
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• 2005

Contamination levels of total aerobic bacteria, coliforms, Esherichia coli, Staphylococcus aureus, Bacillus cereus, and Listeria monocytogenes of Kimbab and its main ingredients sampled from general and specialized restaurants were compared. Total aerobic bacteria and coliform counts of Kimbab samples from both restaurant types were not significantly different (p>0.05), showing approximately $4\;to\;6\;log_{10}CFU/g$. E. coli counts were significantly higher in kimbab from general restaurants ($65%:\;0.7-2.6\;log_{10}CFU/g$) than those from specialized ones ($8.33%:\;0.70log_{10}CFU/g$), whereas those of S. aureus and B. cereus were not significantly different (p>0.05). L. monocytogenes was not detected in all Kimbab samples. These results indicate hygiene of Kimbab and its main ingredients are deleterious. Contamination levels of pathogens determined in the present study may be used as primary data for microbial risk assessment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.5
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• pp.445-453
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• 2012

This study examined microbial contamination during seasoned and dried squid Dosidicus gigas processing, including the apparatus, machines, and employee's gloves at each step in processing at two companies. The numbers of bacteria floating in air in each processing area were also examined. The numbers of Staphylococcus aureus (3.6-6.0 log CFU/g) and Escherichia coli (1.3-1.4 log MPN/100 g) in domestic and imported daruma (a semi-processed product of seasoned and dried squid) at companies A and B exceeded the regulatory limits of the Food Sanitary Law of Korea (S. aureus, ${\leq}2.0$ log CFU/g; E. coli, negative). S. aureus in both daruma was reduced to below the detection limit or 3.6 log CFU/g after the roasting step, but increased again to 3.3 and 5.5 log CFU/g after the mechanical tearing step at companies A and B, respectively. E. coli showed similar tendencies at both companies. The surfaces of the apparatus, machines, and employee's gloves that contacted daruma were also contaminated with S. aureus (1.0-5.5 log CFU/$m^2$) and E. coli (negative-to 3.5 log MPN/$m^2$). The numbers of bacteria floating in air were high (1.7-5.1 log CFU/$m^3$) at both companies. These results suggest that sanitation standard operating procedures (SSOP) must be developed to control of microbial cintamination in seasoned and dried squid.

• Korean Journal of Veterinary Service
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• v.36 no.3
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• pp.203-208
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• 2013

This survey was conducted to evaluate the microbial contamination level of butcher's shops in Seoul, Korea. For microbial inspections, a total of 584 samples (146 cotton work gloves, 146 utensils and equipments, 154 beef samples, 138 pork samples) were collected from butcher's shops. E. coli and pathogenic bacteria such as Staphylococcus aureus, Yersinia enterocolitica, Listeria monocytogenes, Salmonella spp., and E. coli O157:H7 were tested in the samples. As a result, the level of aerobic plate count (APC) ranged ${\leq}10^4\;CFU/cm^2$ from utensils and equipments, $10^1{\sim}10^9$ CFU/glove from cotton work gloves and ${\leq}10^6$ CFU/g from meat. The APC level of E. coli ranged ${\leq}10^1\;CFU/cm^2$ from utensils and equipments, ${\leq}10^5$ CFU/glove from cotton work gloves, and ${\leq}10^3$ CFU/g from meat, respectively. Staphylococcus aureus was detected in 2 beef samples, 1 pork sample, and 10 used cotton work gloves. Yersinia enterocolitica was detected in 3 beef samples, 1 pork sample, and 3 used cotton work gloves. Listeria monocytogenes was detected in 2 used cotton work gloves. In order to improve the sanitation status of butcher's shops, application of HACCP (Hazard Analysis Critical Control Point) or SSOP (Sanitation Standard Operating Procedure), regular hygiene education, and continuous monitoring for microorganisms will be required.

• Biomedical Science Letters
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• v.23 no.4
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• pp.333-338
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• 2017

This study was performed to assess microbial contamination of Aronia melanocarpa, blueberry, raspberry, and cranberry sold in several markets. We investigated total aerobic bacteria and detected foodborne bacteria by multiplex PCR from Aronia melanocarpa, blueberry, raspberry, and cranberry. Total aerobic bacteria of each sample showed mean 3.54 log CFU/g for Aronia melanocarpa, mean 1.90 log CFU/g for blueberry, and mean 1.40 log CFU/g for raspberry, but not detected in cranberry. Specially, Aronia melanocarpa contained high total aerobic bacteria contamination among various berries and contamination level reached 4.17 log CFU/g in sample 5. To evaluate the effect of distribution conditions, we also investigated total aerobic bacteria of various berries. Total aerobic bacteria showed mean 2.89 log CFU/g for berries in refrigerated distribution and 1.40 log CFU/g in frozen distribution, but not in dry distribution. For assessment of foodborne bacteria contamination, we conducted PCR with multiplex primers of E. coli O157, S. aureus, B. cereus, V. parahaemolyticus, L. monocytogenes, Y. enterocolitica, Salmonella spp., Shigella spp. Among these foodborne bacteria, B. cereus was amplified in Aronia melanocarpa in sample 4 and blueberry in sample 1, 2, 3, and 5. The result of quantitative analysis of B. cereus contamination showed 4.08 log CFU/g of Aronia melanocarpa in sample 4 and higher contamination rate 4.07 log CFU/g of blueberry in sample 3. These results suggest that strict food safety control in harvest and distribution of various berries is necessary to prevent foodborne disease and improve microbiological safety.

• Journal of Environmental Health Sciences
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• v.19 no.1
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• pp.30-36
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• 1993

A survey was conducted to measure concentration of airborne microbe in a hospital using RSC air sampler during October~November 1991.The result was as follows: 1) In an agar strip GK-A media for total counts of microbial particles. The highest count were 1384 CFU/m$^3$ in the main lobby, followed by 912 CFU/m$^3$, in the obstetric room, 688 CFU/m$^3$ in 1CU. By gram staining, the distribution for organisms in the air were shown 74.1% in gram possitive cocci followed by 16.8%, in gram possitive bacilli 6.7% in gram negative bacilli and 4.7% in yeast, but low organism was detected in recovery room with 194 CFU/m$^3$. 2) In agar strip S media for Staphylococci the count at the main lobby was detected in the recovery room with 92 CFU/m$^3$, Tests of coagulase were negative Staphylococci with 78%, and positive Staphylococci with 22%. The Staphylococci were highly resistance to penicillin, ampicillin and sensitive to amikacin, cefazolin, gentamycin and chloramphenicol. 3) In agar strip C media for coliform bacteria the colony counts at the main lobby was 139 CFU/m$^3$ and treatment room was 190 CFU/m$^3$, most frequently isolated microorganisms were non fermentative bacilli. 4) In agar strip HS media for yeast and molds. Most frequently colony counts 17~76 CFU/m$^3$, 0.5% lactophenol cotton blue stains were shown unidentified 77.2%, 8.1%, in Penicillium 8.1% in Aspergillus, and 3.8% in mucor.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.5
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• pp.798-802
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• 2009

This study was performed to assess the presence of contaminated microorganisms of Escherichia coli, Clostridium perfringens, and Bacillus cereus in the 112 commercial Saengshik products. E. coli was not detected in all the samples, but C. perfringens was detected in 11 products (9.8%). The number of the bacteria was less than 100 CFU/g, which was satisfactory to KFDA microbiological requirement. B. cereus was detected less than $10^2{\sim}10^3$ CFU/g in 7 products and $10^3{\sim}10^4$CFU/g in 13 products out of 25 products. Those detected bacteria from tryptose sulphite cycloserine agar and mannitol egg yolk polymyxin agar showed the typical characteristics of Gram positive and contained lecithinase, which can decompose egg-yolks layers in the biochemical test. Therefore, much more attention must be applied to satisfy the B. cereus requirement for Saengshik products sold in the market.

• Preventive Nutrition and Food Science
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• v.10 no.4
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• pp.333-339
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• 2005

Three lactobacillus strains, two from infant feces, and one from cow's milk, were selected among 172 isolates, from multiple sources, for further study based on the antimicrobial activities against six strains of pathogenic bacteria and identified as Lactobacillus acidophilus. The strains revealed a wide scope of spectrum against pathogenic bacteria. Viable Lactobacillus acidophilus KH-l cell counts at pH 2.0 were slightly decreased to $1.42\times10^7$ CFU/mL from $4.18\times10^7$ CFU/mL, while remaining at $3.42\times10^7$ CFU/mL at pH 4.0 with the survival rate of $33.97\%\;and\;81.82\%$, respectively. At the concentration of $0.1\%$ oxgall, L acidophilus KH-l kept growing up to $3.12\times10^7$ CFU/mL with a mean growth rate constant (k) of 0.25, and cell number was slightly decreased to $1.21\times10^7$ CFU/mL (k=0.19) with $0.3\%$ oxgall, but remained at $7.6\times10^6$ CFU/mL (k=0.17) with $0.5\%$ oxgall. L. acidophilus KH-l had a $D_{60}$ value of 7.14, with viable cell numbers $1.4\times10^5$ CFU/mL after heat treatment at $60^{\circ}C$ for 30 minutes. Stability of L acidophilus KH-l at $-20^{\circ}C$ was significantly higher, when the strain was cultivated under the optimum growth temperature $(54.41\%\;and\;54.35\%)$ than at the temperature $(13.53\%)$.