• Korean Journal of Environmental Agriculture
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• v.30 no.4
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• pp.459-465
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• 2011

BACKGROUND: Nowadays, Chemical antiseptics have become great problems for health and environmental, so that developing of new substitutes for chemical antiseptics is more and more important. Natural product is a kind of environment-friendly additive that could be used as antiseptic in food industry. Thuja orientalis cv Aurea Nana is a gymnospermous plant of the family Cupressaceae, native to northwestern China and widely naturalised elsewhere in Korea and Japan. This study was aimed to investigate the antibacterial potential of various organic extracts from T. orientalis cones against some food-borne and food-spoilage bacteria. METHODS AND RESULTS: Hexane extract (HE), chloroform extract (CE), ethyl acetate extract (EAE) and methanol extract (ME) were obtained from female cones of T. orientalis. The antibacterial activities of various extracts were tested by standard agar diffusion and minimum inhibitory concentrations (MICs) against five gram-positive and six gram-negative bacteria. Cell viability and morphology change of L. monocytogenes ATCC 10943 treated with hexane extract were also observed. The various extracts displayed remarkable antibacterial effects against all the gram-positive bacteria but did not show any effect against the gram-negative bacteria. Hexane extract has the highest inhibitory effect on cell viability of L. monocytogenes ATCC 10943. SEM observation also demonstrated the damaging effect of the hexane extract on the morphology of L. monocytogenes ATCC 10943 at the minimum inhibitory concentration. CONCLUSION(s): The tested gram-positive bacteria were significantly inhibited by organic extracts of T. orientalis cone. Hexane extract was the most potent against Listeria monocytogenes ATCC 10943, as evidenced by the lowest MIC level and the complete inhibition of cell viability within shortest exposure time, along with SEM observation.

• Journal of Food Hygiene and Safety
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• v.25 no.4
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• pp.376-387
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• 2010

Recently, speedy, convenient and easy detection technologies have been developed rapidly and on the contrary, studies on development of traditional detectors applying biochemical characteristics has gradually been decreased. This review examined trend in current studies on detection of food-borne pathogenic microorganisms in the fields of selective media, immuno-assay, Polymerase Chain Reaction (PCR), microarray, terahertz spectroscopy & imagination and so on. Most traditional methods to detect the organisms from food matrix rely on selective media and such a method have disadvantages like long time requirement and distinguishing one species only from each selective medium although they are highly economical. Various new convenient methods such as Enzyme Linked Immuno-sorbent Assay (ELISA), paper-strip kit, fluoroimmunoassay etc. have been developed. The most ideal method for detecting food-borne pathogenic microorganisms in foods should be accurate, convenient, rapid and economical. Additionally, it is needed that capabilities of quantitative analysis and automation to be applied to industries.

• Korean journal of food and cookery science
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• v.21 no.3 s.87
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• pp.319-325
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• 2005

This study was performed to investigate the antimicrobial effect of the Forsythiae Fructus extracts against food-borne pathogens. First, Forsythiae Fructus was extracted with methanol at room temperature and the methanol extracts were fractionated by using petroleum ether, chloroform, ethyl acetate, and methanol. The antimicrobial activity of the Forsythiae Fructus extracts was determined by using a paper disc method against food-borne pathogens and food spoilage bacteria. The methanol extracts of Forsythiae Fructus showed the highest antimicrobial activity against Salmonella paratryphimurium and Salmonella typhimurium. A synergistic effect in inhibition was observed when Forsythiae Fructus extract was mixed with Ulmus davidiana Japonica extract as compared to each extract alone. Finally, the growth inhibition curves were determined by using ethyl acetate extracts of Forsythiae Fructus against Shigella flexneri and Salmonella paratyphimurium. The aqueous extract of Forsythiae Fructus had strong antimicrobial activity against Staphylococcus epidermidis at the concentration of 10,000 ppm. At this concentration, the growth of Shigella fexneri was retarded for more than 24 hours and for up to 12 hours for Staphylococcus epidermidis. In conclusion, the methanol extracts of Forsythiae Fructus efficiently inhibited Staphylococcus epidermidis and Shigella flexneri.

• 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.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 1999.10a
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• pp.1-27
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• 1999

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1773-1778
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• 2009

Guava (Psidium guajava L.) contains high amount of vitamins and minerals, and its leaves have been reported to be very effective on reducing blood pressure. In this study, antimicrobial characteristics of extracts from four different parts of guava (fruit, branch, leaf, and seed) with four different solvents (methanol, ethanol, acetone, and water) were evaluated. Four targeted food-borne microorganisms were selected; two Gram negatives (Escherichia coli O157:H7 and Salmonella Typhimurium) and two Gram positives (Staphylococcus aureus and Listeria monocytogenes). By the paper disc method, guava extracts showed stronger clear hollow zone against Gram positive bacteria than Gram negatives in nutrient broth agar plate. Especially, extracts of branches and leaves showed significant antibacterial activity. Guava extracts also showed significant inhibition activity on the growth of Gram positive food-borne bacteria in nutrient broth. For example, S. aureus did not grow at all at 200 ppm of acetone extracts of guava branch and leaf. In the case of L. monocytogenes, the same concentration of acetone extracts of guava branch and leaf inhibited the growth 33.5% and 55.4%, respectively, at 32 hrs of incubation time. The results indicated that extracts of guava branch and leaf showed significant antibacterial activities against food-borne Gram positive microorganisms, and that guava branches, the byproducts of guava, might be a valuable resource for antibacterial materials.

• Korean Journal of Plant Resources
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• v.21 no.5
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• pp.352-356
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• 2008

This study was performed to investigate the antimicrobial effects of Origanum majorana L. ethanol extract against food-borne pathogens. The antimicrobial activity of Origanum majorana L. extract was determined using a paper disc method. The extract exhibited growth inhibiting activities in a concentration dependent manner on 10 species microorganisms. The extract of Origanum majorana L. showed the highest antimicrobial activity against Salmonella enteritidis. The growth inhibitory effects of Origanum majorana L. extract on food poisoning microorganisms were determined against Salmonella typhimurium and Listeria monocytogenes, gram negative and positive bacteria, respectively. The extract of Origanum majorana L. had strong antimicrobial activity against Salmonella typhimurium and Listeria monocytogenes at the concentration of $700 mg{\cdot}L^{-1}$. At this concentration, the extract of Origanum majorana L. inhibited the growth of Salmonella typhimurium and Listeria monocytogenes up to 60 and 36 hours, respectively. The results in the present study demonstrate antimicrobial effects of Origanum majorana L. ethanol extract against food-borne pathogens, suggesting that Origanum majorana L. could be an effective natural antibacterial agent in food.

• Journal of Food Hygiene and Safety
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• v.32 no.6
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• pp.500-506
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• 2017

Kimchi cabbage is one of the four major vegetable crops in Korea. The total annual production of kimchi cabbage, the main material of kimchi, was 20,559 tons in 2015. Kimchi cabbage is one of the majer crops produced by farmers which accounts for about 80% of the total leaf vegetable production in Korea. As the consumption of environmental-friendly agricultural products increases, food safety is one of the major public health concerns. We analyzed the biological hazards of kimchi cabbage produced by two types of cultivation methos such as organic farming and conventional farming using various culture media and microscopy. A total of 432 samples were analysed for presence of sanitary indicator microorganisms (aerobic plate count, coliform count, yeast & mold) and food-borne pathogens (Staphylococcus aureus, environmental Listeria, Bacillus cereus). The population of sanitary indicating microorganisms and food borne pathogens was under 5 Log CFU/g in all tested samples. The results of total microorganism numbers of leaf surface showed a positive correlation to those of soil samples. Additionally, we examined chemical factors such as pesticide residues and heavy metals in soil samples. All tested samples did not shown contamination levels higher than the standard limit.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.8
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• pp.1268-1272
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• 2004

The 70% ethanol extract from cactus Chounnyouncho (Opuntia humifusa) was fractionated subsequently by hexan, chloroform, ethyl acetate, buthanol and water. The ethyl acetate fraction exhibited strong antimicrobial activities by paper disk diffusion method on the five strains of food born bacteria Bacillus subtilis, Staphylococcus aureus subsp. aureus, Escherichia coli, Salmonella typhimurium and Pseudomonas fluorescens. It has a heat resistance to show inhibitory effect after heat treatment at 11$0^{\circ}C$ for 1 hr. The ethyl acetate fraction showed almost perfect growth inhibition at over 700 ppm on the tested strains.

• Food Science and Biotechnology
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• v.15 no.1
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• pp.138-142
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• 2006

Various levels of antibacterial activity have been identified for water and ethanol extracts of corn silk, particularly against Salmonella typhimurium KCTC 2515. In general, the water extract was more effective than the ethanol extract. The minimum inhibitory concentration (MIC) for the water extract was 7.5 mg/disc for S. typhimurium KCTC 2515 and B. cereus KCTC 1092, as well as for the ethanol extract against S. typhimurium KCTC 2515 and S. typhimurium KCTC 1925. However, the MICs for the water extract were lower than those for the ethanol extract against all bacteria tested, except S. typhimurium KCTC 1925 and B. cereus KCTC 1014. The growth of the tested organisms in the synthesized broth medium was inhibited with the addition of 5-fold levels of MIC. Using sterilized milk as the model food system, we found that the lag phase for these microorganisms was extended up to 3 days at $20^{\circ}C$, but was not affected at $4^{\circ}C$. These results indicate that bacterial growth was strongly inhibited by corn silk extract at $20^{\circ}C$.