• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.5
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• pp.648-654
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• 2010

This study investigated the antioxidant activities and antimicrobial effects of MeOH extracts from some spices. The total flavonoid contents of MeOH extracts from ginger, garlic, onion, Chinese pepper (Zanthoxylum schinifolium) and black pepper (Piper nigrum) were 20.3%, 10.0%, 4.3%, 6.6% and 12.8%, while the total phenol contents were 19.3%, 1.0%, 0.5%, 3.4% and 7.9%, respectively. The order of the nitrite-scavenging abilities of spice extracts were ginger> black pepper> Chinese pepper> garlic> onion (p<0.05). MeOH extract from ginger showed antimicrobial activity to Bacillus cereus, and garlic extract showed strong antimicrobial activity to Salmonella enteritidis. However, onion extract did not show any antimicrobial activity. The electron donating ability of MeOH extract from ginger was markedly higher than those of garlic, Chinese pepper, black pepper and onion extracts. Antioxidative activities in linoleic acid substrates were in order of BHT> ginger> Chinese pepper> black pepper> garlic> $\alpha$-tocopherol> onion. Antioxidative activities in linoleic acid emulsion substrates were in order of BHT> $\alpha$-tocopherol> ginger> black pepper> Chinese pepper> garlic> onion.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.127-133
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• 2010

The purpose of this work was to investigate the antibacterial activity derived from a lactic acid bacterium, Lactococcus lactis HK-9, isolated from the feces of a 2-day newborn infant. We characterized the physiological and biochemical properties of this strain. Both the BIOLOG system and phylogenetic analysis using 16S rRNA sequencing were utilized for identification, and the strain was assigned to the Lactococcus lactis species, designated as L. lactis HK-9, and registered in GenBank as [GU936712]. We monitored growth rate, production of lactic acid and acetic acid as metabolites, and pH during growth. The maximum concentrations of lactic acid and acetic acid reached 495.6 mM and 104.3 mM, respectively, and the initial pH of the cultures decreased from 7.0 to 4.1 after incubating for 60 h. HPLC was used to confirm the production of lactic acid and acetic acid. Significant antibacterial activity of the concentrated supernatant was demonstrated against Gram-positive (e.g., Staphylococcus aureus, Enterococcus faecalis, Listeria monocytogenes, MRSA) and Gram-negative (e.g., Escherichia coli, Salmonella enteritidis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Shigella sonnei) bacteria by the plate diffusion method. The antibacterial activity was sensitive to protease, and the molecular weight of the presumed bacteriocin molecule was estimated to be about 4 kDa by tricine-SDS-PAGE.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.3
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• pp.389-394
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• 2005

This study was performed to investigate the antimicrobial activity of the Rubia akane Nakai extract against food-borne pathogens. First, the Rubia akane Nakai was extracted with methanol at room temperature and the fractionation of the methanol extract was carried out by using petroleum ether, chloroform, and ethyl acetate, and methanol. The antimicrobial activity of the Rubia akane Nakai extract was determined by using a paper disc method against food-borne pathogens and food spoilage bacteria. The methanol extract of Rubia akane Nakai showed the highest antimicrobial activity against Bacillus cereus and Pseudomonas aeruginosa. Synergistic antimicrobial effect was observed when Rubia akane Nakai extract was mixed with Viscum album var. coloratum extract as compared to each extract alone. Finally, the growth inhibition curves were determined by using methanol extract of Rubia akane Nakai against Bacillus cereus and Pseudomonas aeruginosa. The methanol extract of Rubia akane Nakai had strong antimicrobial activity against Pseudomonas aeruginosa at the concentration of 4,000 ppm. At this concentration, the growth of Pseudomonas aeruginosa was retarded more than 72 hours and up to 48 hours for Bacillus cereus. From these results, it was concluded that the methanol extract of Rubia akane Nakai inhibited effectively Bacillus cereus and Pseudomonas aeruginosa.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.6
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• pp.822-826
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• 2007

This study was conducted to determine the effects of a 0.5% sodium alginate eggshell coating, that was applied at two temperatures, 5 and $25^{\circ}C$, by examining the degree of microbial inhibition on the eggshell surface as well as the coating's effects on egg quality during storage. A significant portion of human Salmonella enteritidis infection is traced to food contamination, and eggs are often highly exposed to this type of contamination. The 0.5% sodium alginate coating's effect for inhibiting microbial growth on the eggs, at $25^{\circ}C$ for 7 days, was one hundred thousand times more effective than that of the uncoated eggs. The pH level in eggs increases as the eggs lose $CO_2$ and as the storage temperature increases. We found that the pH of the coated eggs was lower than that of the uncoated eggs. The pH for the uncoated eggs changed from 7.72 to 7.94 over 30 days of storage at $5^{\circ}C$. However, when the eggs were coated with 0.5% sodium alginate, the pH changed from 7.72 to 7.85 over 30 days of storage at $5^{\circ}C$. The Haugh unit was 66.02 for the uncoated eggs and 70.37 for the 0.5% sodium alginate coated eggs after 30 days of storage. The yolk index of the eggs coated with sodium alginate was higher than that of the uncoated eggs after 30 days. These results indicate that a sodium alginate coating on eggs can serve as protection from microbes and is effective in preserving the interior quality of eggs.

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.472-479
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• 2002

The antimicrobial effects of metabolites from isolated strains from feces of Korean newborn baby and from Dongchimi against six food-borne microorganisms, and characteristics of the metabolites were investigated.. The metabolites from isolated strains adjusted pH to 3.5, 4.0, and 4.5 showed strong growth inhibition against S. Typhimurium, and S. Enteritidis. The metabolites has kept its inhibition activities to the pathogens after catalase, trypsin or pepsin treatment. In addition, antimicrobial activity of metabolites was not decreased by heat treatment at $121^{\circ}C$ for 15 min. D2 and F35-2 strains were confirmed homofermentative and F20-3 was heterofermentative bacteria identified by final organic acid and gas production. The amount of lactic acid produced by D2 and F35-2 strains after 24 h of incubation was 1.84 and 1.85% respectively, but F20-3 strain produced acetic acid (0.22%) and lactic acid (0.91%).

• Journal of Food Hygiene and Safety
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• v.29 no.4
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• pp.376-382
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• 2014

Various solvents (chloroform, hexane, ethyl acetate, ethanol, methanol, and hot water) were tested to investigate the antimicrobial activities of sword bean (Canavalia gladiata) against 12 food poisoning bacteria. Chloroform, hexane, ethyl acetate and hot water extracts had no antimicrobial activities, but ethanol extract showed V. parahemolyticus 10 mm, S. sonnei 9 mm, and methanol extract showed strong activities in order of V. parahemolyticus 22 mm, S. sonnei 21 mm, L. monocytogenes 20 mm by disk diffusion. The minimal inhibitory concentrations (MICs) were also determined. The methanol extract had MIC values of 50 mg/mL against S. Typhimurium, V. parahemolyticus, and S. sonnei and values of 100 mg/mL against other 7 food poisoning bacteria and values of 200 mg/mL against Y. enterocolitica and MRSA. The inhibitory effect of methanol sword bean extract on the growth of V. parahemolyticus was investigated. Growth of the strain occurred at the concentration of 0.5% extract and was inhibited continuously at 1.0 and 1.5% for 30hours after inoculation, whereas the strain was completely inhibited at 2.0% after 9hours of inoculation.

• Korean journal of food and cookery science
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• v.21 no.1 s.85
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• pp.40-46
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• 2005

This study was performed to investigate the antimicrobial effects of the Citrus unshiu Markovich extracts against food-borne pathogens. First, the Citrus unshiu Markovich was extracted with methanol at room temperature, and fractionation of the methanol extracts from Citrus unshiu Markovich was carried out by using petroleum ether, chloroform, ethyl acetate, and methanol. The antimicrobial activity of the Citrus unshiu Markovich extracts was determined using the paper disc method against food-borne pathogens and food spoilage bacteria. The ethyl acetate extracts of Citrus unshiu Markovich showed the highest antimicrobial activity against Bacillus cereus and Shigella sonnei. A synergistic effect was found in combined extracts of Citrus unshiu Markovich and Hedyotis diffusa Willd as compared to each extract alone. Finally, the growth inhibition curve was determined using ethyl acetate extracts of Citrus unshiu Markovich against Bacillus cereus and Shigella sonnei. The ethyl acetate extract of Citrus unshiu Markovich showed strong antimicrobial activity against Bacillus cereus at the concentration of 5,000 ppm. The 5,000 ppm of ethyl acetate extract from Citrus unshiu Markovich retarded the growth of Bacillus cereus more than 24 hours and Shigella sonnei up to 24 hours. The ethyl acetate extracts of Citrus unshiu Markovich have shown an antimicrobial effect against Bacillus cereus and Shigella sonnei.

• Korean journal of food and cookery science
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• v.20 no.2
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• pp.204-210
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• 2004

This study was performed to provide basic physiological activities data to predict the usefulness of olive leaves as a food material. Total flavonoid and total phenol contents of 80% ethanol extract of olive leaf were 5.81% and 14.8%, respectively. Total flavonoid and total phenol contents were markedly higher in butanol and ethyl acetate fractions than in hexane, chloroform, and water fractions (p＜0.05). Oleuropein in olive leaf was the major phenolic compound. The oleuropein contents of 80% ethanol extract, butanol and ethyl acetate fractions of olive leaf were 102.11${\pm}$0.02, 173.35${\pm}$0.03 and 152.71${\pm}$0.03 mg/100g, respectively. The 80% ethanol extract, butanol and ethyl acetate fractions of olive leaf showed a growth inhibitory effect to Bacillus cereus, Staphylococcus aureus, Escherichia coli, and Salmonella enteritidis, whereas antimicrobial activities of hexane and chloroform fractions were not observed. The inhibitory activity to ACE was determined to be very weekly positive in 80% ethanol extract and all fractions of olive leaf. The nitrite-scavenging ability of 80% ethanol extract, butanol and ethyl acetate fractions of olive leaf were 72.8%, 76.0% and 75.4%, respectively. Significant evidence was detected that the butanol and ethyl acetate fractions showed higher activity than that of hexane, chloroform, and water fractions (p＜0.05).

• Journal of Marine Bioscience and Biotechnology
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• v.2 no.2
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• pp.113-119
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• 2007

In this study, we investigated antimicrobial and cytotoxicity effects of Gelidium amansii L., which using methanol, dichloromethane and ethanol were extracted and fractionated into four different types : methanol (GAMM), hexane (GAMH), butanol (GAME) and aqueous (GAMA). The antimicrobial activity was increased in proportion to its concentration by the paper disc method. Among the solvent fractions, The methanol partition layer (GAMM) showed the strongest antimicrobial activities and cytotoxic effects on all cancer cell lines. We also observed quinone reductase (QR) induced effects in all fraction layers of GA on HepG2 cells. The QR induced effects of GAMM on HepG2 cells at $40{\mu}g/mL$ concentration indicated 2.5 with a control value of 1.0.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.7
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• pp.948-952
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• 2005

The antioxidative and antimicrobial properties of the solvent extracts of 3 parts (leaf, stem, root) of Crotalaria sessiflora L. were investigated, in order to find out new natural food additives. The antioxidative activities of the extracts were determined by peroxide value (POV) and the conjugated diene value (CDV) of corn oil stored for 30 days at $60\pm2^{\circ}C$. Each part of the extracts were added as $0.02,\;0.05\%$ and then compared with BHT. The anti oxidative activities were as follows in decreasing order: BHT > LeafEX > StemEX > RootEX > control. The induction period showed that the part of the Crotalaria sessifloria L. group added with solvent extract showed a longer induction period compared with the control group. The part of Crotalaria sessiflora L. solvent extract were shown to have antimicrobial effects on the microorganism such as Bacillus subtilis, Staphylococcus aureus, Listeria monocytogenes, Salmonella Enteritidis, Pseudomonas flrourescens and Escherichia coli. Especially the effect on the Pseudomonas flrourescens was remarkable.