• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.3
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• pp.429-436
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• 1998

A bacteriological study of sea water and oyster in Charan Bay was conducted to evaluate sanitary conditions of the bay and compliance of waters with the recommended bacteriological criteria for the designated area of shellfish cultivation, The Samples were collected at 23 sampling stations(Fig. 1 and Fig. 2) estaslished once a month from January 1997 to December 1997, During the study period, temperature ranged from 4.7 to $25.6^{\circ}C$, transparency ranged from 3.3 to 6.2m chemical oxygen demand ranged from 1.67 to 2.18 mg/$\ell$, dissolved oxygen demand ranged from 5.4 to 10.0 mg/$\ell$ dissolved nitrogen ranged from 1.65 to 7.88 $\mu$g-at/$\ell$, phosphate ranged from 0.15 to 1.16 $\mu$g-at/$\ell$, Chlorophylla-a ranged from 0.95 to 12.69mg/$\ell$. The coliform group and fecal coliform MPN's of sea water were ranged from <1.8$\~$l,600 and <1.8$\~$540, respectively. The coliform group and fecal coliform MPN's of oysters were ranged from <18$\~$16,000 and <18$\~$1,400, respectively. The viable cell counts in oyster ranged from $1.5\times10^2$ to $7.5\times10^3$. The bacteriological criteria of sea water in shellfish growing area should be less than 70 per 100 ml of sea water for median value of coliform MPN, and below $10\%$ of the samples which contain over than 230 for coliform MPN or over than 43 for fecal coliform MPN. The sea water from 432 samples were complied water coliform criteria recommended for designated shellfish growing area. The coliform group, fecal coliform, classification of coliform group with IMViC reactions and pathogenic vibrios were analyzed. During the study period, infectious bacteria such as Vibrio cholerae, Salmonella sp, and Shigella sp, were not detected from the samples, but detection ratios of Vibrio parahaemolyticus and Vibrio vulnifirus were $7\~17\%$ in summer months.

• Journal of Nutrition and Health
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• v.45 no.1
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• pp.12-19
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• 2012

The present study was performed to investigate antioxidant, anticancer, and antimicrobial activities of four Korean sweet potato variaties and to identify the changes in these biological activities under different cooking conditions. Total polyphenol content was 3.8-73.6 mg/g in 80% ethanol extracts of sweet potatoes. The polyphenol content was highest Sinjami variety (p < 0.05). Radical scavenging activity against DPPH and $ABTS^{{\cdot}+}$ was high in Sinjami (p < 0.05) and the ethanol extract from Sinjami also showed effective superoxide dismutase (SOD)-like activity, which decreased significantly by steaming and roasting (p < 0.05). Ethanol extracts from the four sweet potato variaties did not inhibit cancer cell growth in MCF-7 or HepG2 cells at concentrations of 1, 10, and $100\;{\mu}g$/mL. Of the investigated sweet potato variaties, only Sinjami exhibited strong antimicrobial activity against Escherichia coli, Staphylococcus aureus, and Salmonella typhimurium. The antimicrobial activity of Sinjami against E. coli, St. aureus, and S. typhimurium decreased following steaming and roasting (p < 0.05). These results indicate that the Sinjami Korean sweet potato had higher polyphenol content, radical scavenging activity, SOD-like activity, and antimicrobial activity than those of the other variaties and consuming raw Sinjami might be beneficial for maintenance of biological activities.

• Food Science and Preservation
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• v.16 no.3
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• pp.419-426
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• 2009

The antioxidant and antimicrobial effects of acid-soluble and pepsin-solubilizable shark (Isurus oxyrinchus) collagens (SC) (ASSC: acid-soluble shark skin collagen, ASMC: acid-soluble shark meat collagen, PSSC: pepsin-solubilizable shark skin collagen, PSMC: pepsin-solubilizable shark meat collagen) and standard marine collagen (STMC) as materials, and the ability of these materials to inhibit tyrosinase and elastase, were investigated. The electron-donating ability of SC ($1{\sim}5\;g/mL$) was $14.91{\sim}17.21%$, which was $3.0{\sim}3.6$-fold higher than that of STMC at the same concentration. Also, the SOD(superoxide dismutase)-like activity of SC (5.80 mg/mL) was $4.67{\sim}37.28%$, thus $3.0{\sim}3.6$-fold greater than that of STMC. The MIC values of SC against Staphylococcus aureus and Salmonella enteritidis were $5{\mu}g$/disc, which were remarkably lower than that of STMC ($200{\mu}g$/disc). There was no antimicrobial activity against Escherichia coli in STMC, but the MIC against E. coli was $200{\mu}g$/disc for acid-soluble SC and $100{\mu}g$/disc for pepsin-solubilizable SC. The inhibition of tyrosinase by SC (3-5 mg/mL) was $58.95{\sim}98.16%$, $3.34{\sim}3.74$-fold higher than that of STMC ($17.67{\sim}26.25%$). Also, elastase inhibition by SC (at 1 mg/mL) was $53.33{\sim}80.0%$, $1.1{\sim}4.0$-fold greater than that of STMC. These results indicated that shark collagens may be valuable new functional materials owing to their antioxidant and antimicrobial properties, and because the inhibitory activities against elastase and tyrosinase are better than those of standard marine collagen.

• Journal of Life Science
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• v.20 no.10
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• pp.1532-1537
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• 2010

This study compared the inhibitory effects of methanol extracts from yellow and black soybeans (black soybean, Seomoktae and Seoritae) on mutagenicity using the Ames test and growth of human cancer cells (AGS human gastric adenocarcinoma, HT-29 human colon cancer, Hep 3B hepatocellular carcinoma cells). In the Ames test system using Salmonella typhimurium TA100, aflatoxin $B_1$ ($AFB_1$)-induced mutagenicity was significantly inhibited by treatments with the methanol extracts from either yellow or black soybeans in a dose dependent manner (p<0.05). The methanol extracts from various black soybeans tended to have a greater inhibitory effect compared to those from yellow soybeans. As for N-methyl-N'-nitro-N-nitrosoguamidine (MNNG)-induced mutagenicity, the methanol extracts (5 mg/assay) from black soybean, Seomoktae and Seoritae showed 51%, 61% and 53% inhibitory rates, respectively, indicating that Seomoktae, a type of black soybean, had a stronger antimutagenic activity against mutagens (both $AFB_1$ and MNNG). Methanol extracts from black soybeans showed an inhibitory rate of greater than 50% on the growth of human cancer cells (AGS, HT-29 and Hep 3B) and the inhibition was more effective in the methanol extract from Seomoktae. Our results suggested that the methanol extracts from black soybeans showed stronger inhibitory effects on mutagenicity and growth of cancer cells than those from yellow soybean. It is concluded that intake of black soybean can be recommended for improving health.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.1
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• pp.116-122
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• 2011

This study was conducted to investigate the microbiological hazard of spoons and their cases carried by nursery school children and to evaluate the reduction effects of washing methods and ultraviolet (UV) treatments against Escherichia coli on the spoon and spoon case. A total of 78 spoons and their cases were sampled to test about total aerobic bacteria, coliform bacteria, Staphylococcus aureus, Bacillus cereus and Salmonella spp. Total aerobic bacteria were detected over 2.7 log CFU/100 $cm^2$ in 20 out of 36 spoons (55.6%), 9 out of 20 zipper-type spoon cases (45.0%) and 13 out of 22 plastic-type spoon cases (59.1%). Coliform bacteria were also detected in 19 out of 36 spoons (52.8%), 14 out of 20 zipper-type spoon cases (70.0%) and 14 out of 22 plastic-type spoon cases (63.6%). The pathogens tested in this study were not found in all samples except for the zipper-type spoon cases which were contaminated with Staph. aureus (2 samples) and B. cereus (3 samples). The results indicated that the sanitary conditions of spoons and their cases should be improved promptly. To evaluate the reduction effects of washing methods and UV treatments against E. coli, the spoons and their cases were treated at different cleaning times with and without soap, and different UV exposure times, respectively. E. coli with initial cell number of 4 log CFU on the spoons and their cases was not detected when they were cleaned at running water for 30 sec after dish sponging with soap for 30 sec. In UV treatments, E. coli with the same level of washing method was not detected after UV exposure for 15 minute in the spoons and their cases. From the results, the washing and UV treatment should be used to control the microbial contamination of spoons and their cases for more than 1 and 15 minutes, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.5
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• pp.577-583
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• 2012

This study investigated the antioxidant activities, and antimicrobial activity $in$ $vitro$ of an 80% ethanol extract from garlic, daikon, leek, ginger, onion, and green onion, which are widely-used ingredients in Korean food that contain sulfur. The total polyphenol content in ginger and leek extracts showed a high value ($233.63{\pm}4.59$ and $220.98{\pm}10.56$ mg/g GAE) and onions, leeks, garlic, and daikon followed by with $69.07{\pm}1.42$, $68.83{\pm}2.11$, $19.41{\pm}0.40$, $19.05{\pm}03.32$ mg/g GAE, respectively. DPPH radical scavenging activity was highest with ginger extracts ($1.57{\pm}0.15$ mg/mL as $IC_{50}$) followed in order of decreasing activity by leeks, onions, daikon, green onions, and garlic. The results of ABTS radical scavenging activity and FRAP value showed higher antioxidant activity in extracts from ginger and leek. The order of vegetables with most to least prevalent ABTS radical scavenging activity was green onions, onions, garlic, and finally daikon. From greatest to least FRAP value, the relevant vegetables were green onions, onions, daikon, and garlic (p<0.05). Ginger extracts showed promise against seven strains of microbes: $Bacillus$ $cereus$, $Bacillus$ $subtillis$, $Staphylococcus$ $aureus$, $Lactobacillus$ $plantarum$, $Escherichia$ $coli$, $Salmonella$ $enterica$, and $Pseudomonas$ $aeruginosa$. Garlic extracts (5 mg/disc) showed strong antimicrobial activity against $B.$ $cereus$ (22.3 mm) and $E.$ $coli$ (24.3 mm). Extracts of both onion and green onion showed antimicrobial activity against only $E.$ $coli$ (12.7 and 10.3 mm) and $B.$ $cereus$ (12.0 and 12.5 mm) at 10 mg/disc, and the inhibition zone diameter from extracts of garlic and leeks were 18.0 mm and 10.4 mm vs. $L.$ $plantarum$ at 10 mg/disc. This study showed positive antioxidant activities for ginger and leeks, and positive antimicrobial activities for leeks and garlic. These sulfur-containing vegetables are widely used in Korean food. Leeks especially could serve as a functional food preservative.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.8
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• pp.1049-1057
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• 2008

The purpose of this study was to microbiologically evaluate common foods and preparation processes in three large (over 100 pyeong) western-style restaurants in Daegu. Microbiological testing was conducted for pathogens including E. coli, Salmonella spp., Listeria monocytogenes, Staphylococcus aureus, E. coli O157:H7, Vibrio parahaemolyticus, and Bacillus cereus, as well as total plate count and coliforms. Food samples selected for testing represent common menu items and preparation processes. These samples included: 1) hamburger steak (cooking process), 2) mashed potatoes (reheating process), and 3) salad (non-heating process). The results showed that E. coli and S. aureus were detected in the raw ground beef used to prepare hamburger steak, but they were not detected after cooking at $82{\sim}86^{\circ}C$, 10 min. Microbiological quality of the mashed potatoes was better after reheating than during storage in a refrigerator after cooking. Total plate count and coliforms increased, and E. coli was detected in the salad ingredients stored in the refrigerator before serving. In order to serve foods of good microbiological safety and quality in western-style restaurants, standard cooking and reheating temperatures must be maintained during the cooking and reheating processes, and sanitation standard operating procedures must be followed for washing and storage of non-heated and refrigerated menu items.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.7
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• pp.1041-1048
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• 2016

Biofilm cells and viable but non-culturable (VBNC) state may play a role in the survival of Campylobacter jejuni under unfavorable environmental conditions. The objective of this study was to investigate the behavior of C. jejuni biofilm cells and VBNC cells on smoked duck. The transfer of C. jejuni biofilm cells to smoked duck and its ability to resuscitate from biofilm and VBNC cells on smoked duck was investigated. Transfer experiments were conducted from C. jejuni biofilm cells to smoked duck after 5 min, 1 h, 3 h, and 24 h contact at room temperature, and the efficiency of transfer (EOT) was calculated. In addition, smoked duck was inoculated with C. jejuni biofilm and VBNC cells and then stored at 10, 24, 36, and $42^{\circ}C$ to examine the cells' ability to resuscitate on smoked ducks. The 5 min contact time between C. jejuni biofilm cells and smoked duck showed a higher EOT (0.92) than the 24 h contact time (EOT=0.08), and the EOT decreased as contact time increased. Furthermore, C. jejuni biofilm cells on smoked duck were not recovered at 10, 24, and $36^{\circ}C$, and C. jejuni VBNC cells were not resuscitated at $42^{\circ}C$. Although the resuscitation of C. jejuni biofilm and VBNC cells was not observed on smoked duck, microbial criteria of C. jejuni is needed in poultry and processed poultry products due to risk of its survival and low infectious dose.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.7
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• pp.1003-1007
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• 2013

In this study, the antibacterial activities of selected barleys (UB, unhulled barley; PB, pearl barley; and NB, naked barley) and wheat (WG, wheat with germ and endosperm) extracts were evaluated against the food-borne pathogens Staphylococcus aureus KCTC 1927, Escherichia coli KCTC 2593, Salmonella Typhimurium KCTC 2054, and Bacillus cereus KCTC 1014. The amount of the antibacterial biomarker, 2,6-dimethoxy-1,4-benzoquinone (DMBQ), present in selected barleys and wheat, was measured by HPLC. Furthermore, antioxidant activity of samples was determined using the oxygen radical absorbance capacity (ORAC) assay. WG ($22.35{\pm}0.04mm$) was found to be highly inhibitory to Staphylococcus aureus followed by UB ($17.91{\pm}0.10mm$), PB ($16.87{\pm}0.05mm$), and NB ($15.69{\pm}0.20mm$). The antibacterial activity of the selected grains was correlated with antioxidant activities and the amount of DMBQ (Pearson's correlation coefficient, 0.7831). The antioxidant activity of the selected grains was also correlated with the total phenolic content (Pearson's correlation coefficient, 0.9934). WG extract showed significantly higher antibacterial activity, compared with barley extracts such as UB, PB, and NB. The results of this study suggest that barley has a potential in the development of natural antimicrobials and food preservatives for controlling food-borne pathogens.

• Clinical and Experimental Pediatrics
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• v.45 no.8
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• pp.967-972
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• 2002

Purpose : A retrospective study was undertaken to evaluate the usefulness of low risk criteria for identifying febrile infants younger than three months unlikely to have serious bacterial infection. Methods : We conducted a retrospective study of 527 infants younger than three month with a axillary temperature ${\geq}37.4^{\circ}C$. If they met the following all four criteria, appear well, WBC $5,000-20,000/mm^3$, urine stick WBC(-) and nitrite(-), CSF WBC < $10/mm^3$, they were considered at low risk for serious bacterial infection(SBI). SBI was defined as a positive culture of urine, blood, or cerebrospinal fluid. The sensitivity, specificity, negative predictive value and positive predictive value of the low risk criteria were calculated. Results : Of 527 febrile infants, 110(21.0%) had serious bacterial infections. The 2.7% who met the low risk criteria had SBI and negative predictive value was 97.3%. SBI was diagnosed in 103 infants(38.6%) who didn't meet the low risk criteria including urinary tract infection(78.6%), most commonly, bacteremia(16.5%), bacterial meningitis(8.7%), Salmonella gastroenteritis(1%), osteomyelitis( 1%), septic arthritis of hip joint(1%). There were no differences in the sensitivity and negative predictive value according to the monthly-age-group. Conclusion : This low risk criteria to identify infants unlikely to have SBI early is available, however low risk infants must be carefully observed.