• Food Science and Preservation
• /
• v.20 no.5
• /
• pp.727-734
• /
• 2013

The antifungal activity against cheese fungi by lactic acid bacteria isolated from kimchi was investigated. Eight fungi were isolated from cheese in the cheese ripening room. Two of them were identified as Penicillium and Cladosporium via ITS-5.8S rDNA analysis. Twenty-two species of lactic acid bacteria with antifungal activity were isolated from kimchi. Two of them were identified as Lactobacillus and Pediococcus via 16S rRNA sequence analysis. Of the 22 lactic acid bacteria species, six were selected (L. sakei subsp. ALJ011, L. sakei subsp. ALI033, L. sakei subsp. ALGy039, P. pentosaceus ALJ015, P. pentosaceus ALJ024 and P. pentosaceus ALJ026) due to their higher activity against the eight fungi isolated from cheese in the cheese ripening room; and among the six species, the P. pentosaceus ALJ015 and P. pentosaceus ALJ024 isolates from the Jeonju area kimchi and the L. sakei subsp. ALI033 isolate from the Iimsil area kimchi had higher antifungal activity than the other lactic acid bacteria. The minimum inhibitory concentration (MIC) of L. sakei subsp. ALI033 against the eight fungi isolated from cheese in the cheese ripening room was $62.5{\mu}g/mL$.

• Journal of Life Science
• /
• v.21 no.4
• /
• pp.589-595
• /
• 2011

This work focused on screening and characterizing antibiotic-producing actinomycetes to develop new antibiotics that can overcome the growing resistance of disease-causing microbes. One-hundred actinomycetes strains were isolated from soil samples from Chungcheongbuk-do, Korea using various kinds of actinomycetes isolation media, including a starch casein agar medium and potato dextrose agar (PDA). Among them, strain BCNU 1030 was determined to show strong antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA). Biochemical, physiological, and 16S rRNA sequence analyses indicated that strain BCNU 1030 belonged to the genus Streptomyces. Strain BCNU 1030 exhibited antibiotic activity against a wide range of bacteria, especially methicillin-resistant Staphylococcus aureus (MRSA). The minimum inhibitory concentration (MIC) of BCNU 1030 dichloromethane extract was determined to be $0.78\;{\mu}g/ml$ for MRSA CCARM 3090. Therefore, Streptomyces sp. BCNU 1030 has potential for anti-MRSA drug development.

• Food Science and Preservation
• /
• v.22 no.1
• /
• pp.12-18
• /
• 2015

The objective of this research was to investigate the antioxidant and antimicrobial activities of muscadine grape extracts. Three different cultivars of muscadine grapes including Higgings, Jumbo, and Noble were selected. The skin/pulp and seed parts of three selected muscadine grape cultivars were used for extraction. The total phenolic contents of muscadine grape extracts were expressed as gallic acid equivalents (GAE). The antioxidant activity of muscadine grape extracts were determined by scavenging activity of diphenylpicrylhydrazyl (DPPH) radical and expressed as effective concentration ($EC_{50}$), which represented the concentration of the extract exhibiting 50% DPPH radical scavenging. The antimicrobial activity against E. coli K12 was determined and expressed as the minimum inhibition concentration (MIC). The seed extracts exhibited greater total phenolic contents than the skin/pulp extracts, ranging from 231.24 to 294.81 mg/mL GAE. The seed extracts exhibited greater antioxidant activities than the skin/pulp extracts ($EC_{50}$ of Higgins seed extract=0.026 mg/mL). However, the skin/pulp extracts exhibited greater antimicrobial activities than the seed extracts, exhibiting the minimum inhibition concentration (MIC) in Higgins skin/pulp extract (MIC=4.0 mg/mL). This research indicated that the seed part and skin/pulp parts of the muscadine grapes possessed antioxidant activity and antimicrobial activity, respectively. Therefore, it was concluded that muscadine grapes possess the potential to be utilized as functional foods or nutraceuticals.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.39 no.10
• /
• pp.1565-1572
• /
• 2010

Onion (Allium cepa L.) production in Korea has increased gradually over the past 15 years, placing second in food consumption survey with 20.6 g daily intake in 2006. Onions, used as an ingredient in many dishes and accepted by almost all traditions and cultures, have been reported to have a range of health benefits which include anticarcinogenic, antiasthmatic, antibiotic, and antioxidative effects. These effects may be attributable to a powerful flavonoid pigment-containing compounds, such as quercetin and alk(en)yl cysteine sulphoxides (ACSOs). Although antiplatelet and antithrombotic activities of onion have been confirmed by many of in vitro or animal studies, only a few human intervention studies have been examined. The majority of human studies identified that onion improves some cardiovascular markers such as lipid profile and platelet coagulant. With regard to antioxidative effects, somewhat positive effects are confirmed through strengthening the resistance of oxidative DNA damage in lymphocyte and urine, while most studies failed to find inhibitory effects on LDL oxidation. The discrepancies among studies might be ascribed to producing area, processing methods of onion, dosage, subject characteristics, study duration, and measurement methods. In this review, we focused on the preventive effect of cardiovascular disease through onion consumption in human intervention studies.

• Microbiology and Biotechnology Letters
• /
• v.42 no.2
• /
• pp.145-151
• /
• 2014

The antibacterial effect of Quercus salicina Blume extract was investigated and then the stability of a cream containing it best performing fraction, the ethyl acetate fraction, was evaluated. The antibacterial effect was evaluated on the skin microorganisms Staphylococcus aureus, Bacillus subtilis, Propionibacterium acnes, Escherichia coli, and Pseudomonas aeruginosa. Among the Q. salicina Blume extract fractions, the ethyl acetate fraction demonstrated the lowest minimum inhibitory concentration against S. aureus (1,200 ${\mu}g/ml$), B. subtilis (2,500 ${\mu}g/ml$), P. acnes (1,200 ${\mu}g/ml$) and P. aeruginosa (312 ${\mu}g/ml$). Therefore, a cream containing 0.25% ethyl acetate fraction of Q. salicina Blume extract was prepared and evaluated for stability. The pH, viscosity, and absorbance of the cream were measured under various temperatures (4, 20, 37, $45^{\circ}C$) and sun light during a 12 week period. The changes in viscosity, absorbance and pH of the cream did not change significantly during the term of the experiment when compared with a placebo cream. In addition, any change in color or odor of the cream was not observed during the 12 weeks. These results indicate that the ethyl acetate fraction of Q. salicina Blume extract has a high antibacterial effect and is stable as a cream. There is therefore some potential for its use in cosmetic materials.

• Korean Journal of Food Science and Technology
• /
• v.38 no.1
• /
• pp.35-41
• /
• 2006

Possible application of hurdle technology extention of shelf-life of fresh-cut apples was investigated by evaluating various hurdle factors known to be effective microbial growth inhibitors and their synergistic effects. Fresh-cut apples treated with chitooligosaccharide or grapefruit seed extract (GSE) showed higher microbial counts than those treated with distilled water during latter half of storage period, and at high concentrations. Citric and malic acids showed similar results, although microbial counts of fresh-cut apples treated with 0.75% or higher concentration of citric acid increased at 4 days of storage at $18^{\circ}C$, indicating malic acid is more effective than all hurdles tested for controlling microbial growth. Using ascorbic acid and calcium chloride as additional hurdles to control browning and softening, minimum and maximum compositions of dipping solution were: 0.25 : 0.5 : 0.25% and 0.75 : 1.0 : 0.75% malic acid: ascorbic acid: calcium chloride, respectively.

• Korean Journal of Food Science and Technology
• /
• v.33 no.5
• /
• pp.611-618
• /
• 2001

The ethanol extract of Dryopteris crassirhizoma Nakai showed strong growth inhibition against 5 strains of Listeria monocytogenes at the concentrations of $100{\sim}500$ ppm and the minimum inhibitory concentration of n-hexane fraction was under 50 ppm. The D8-2-5 fraction isolated from n-hexane fraction of Dryopteris crassirhizoma Nakai showed a strong bactericidal activity on 5 strains of L. monocytogenes at 20 ppm level in tryptic soy broth medium. At the level, the viable count was reduced $4{\sim}6$ log cycle compared to initial cell number. Observation by the measurement of adenosine triphosphate (ATP) contents and transmission electron microscope showed that disruptions of the cell wall and elution of intracellular ATP are assumed to be due to the bactericidal activity. In addition, the n-hexane fraction of Dryopteris crassirhizoma Nakai showed the strong growth inhibitions at 50 ppm on Vibrio parahaemolyticus and Bacillus cereus, and at 25 ppm on Staphylococcus aureus.

• The Journal of the Korea Contents Association
• /
• v.19 no.1
• /
• pp.242-255
• /
• 2019

In this study, we examined the antimicroboal effect against Actinobacillus actinomycetemcomitans and Prevotella intermedia which were the bacteria causing the Periodontopathic by using 34 types of natural plant extracts. Therefore, this study measures growth inhibition activity and Minimum Inhibition Concentration (MIC) of a sample extract with the use of organic solvent extracts in order to analyze the antibacterial effect of natural plant extracts on periodontopathic bacteria. Each of the 34 types of natural plant extracts were extracted by using the ethanol, and subsequently, the size of growth inhibition zone(clear zone, ㎜) of respective extracts were measured through the disk diffusion method. As a result, it was found that the growth inhibitory activity was found for A. actinomycetemcomitans, which is the bacteria causing the Periodontitis, in 13 types of natural plant extracts such as Raphanus sativus, Akebia quinata, Paeonia lactiflora, Belamcanda chinensis, Inula britannics, Houttuynia cordata, Forsythia saxatilis, Gentiana macrophylla, Melia azedarach, Scutellaria baicalensis, Coptis chinensis, Phellodendron amurense, Kalopanax Pictus, etc. In the case of P. intermedia, the growth inhibitory activity was found in 13 types of natural plant extracts such as Raphanus sativus, Angelica acutiloba, Akebia quinata, Belamcanda chinensis, Inula britannics, Houttuynia cordata, Cinnamomum cassia, Aster tataricus, Melia azedarach, Scutellaria baicalensis, Coptis chinensis, Phellodendron amurense, Kalopanax Pictus etc. For A. actinomycetemcomitans, anti-bacterial effect was exhibited in Belamcanda chinensis, Cinnamomum cassia, Kalopanax Pictus, Phellodendron amurense, Coptis chinensis. The Coptis chinensis showed the most excellent growth inhibitory activity in all organic solvent fragment, while P. intermedia showed the growth inhibitory activity in Belamcanda chinensis, Cinnamomum cassia, Meliaazedarach, Phellodendron amurense, and Coptis chinensis.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.41 no.4
• /
• pp.361-373
• /
• 2015

This study was carried out to evaluate the antioxidant and antibacterial activities of Glycyrriza uralensis Fisher (Jecheon, Korea) extracts obtained by various extraction conditions (85% ethanol, heating temperatures and times), and to establish the optimal extraction condition of G. uralensis for the application as cosmetic ingredients. The extracts obtained under different conditions were concentrated and made in the powdered (sample-1) and were the crude extract solutions without concentration (sample-2). The antioxidant effects were determined by free radical scavenging activity ($FSC_{50}$), ROS scavenging activity ($OSC_{50}$), and cellular protective effects. Antibacterial activity was determined by minimum inhibitory concentration (MIC) on human skin flora. DPPH free radical scavenging activity of sample-1 ($100{\mu}g/mL$) was 10% higher in group extracted for 6 h than 12 h, but sample-2 didn't show any significant differences. The extraction yield extracted with same temperature for 12 h was 2.6 times higher than 6 h, but total flavonoid content was 1.1 times higher. These results indicated that total flavonoid content hardly increased with increasing extraction time. Free radical scavenging activity, ROS scavenging activity and cellular protective effects were not dependent on the yield of extraction, but total flavonoid content of extraction. Antibacterial activity on three skin flora (S. aureus, B. subtilis, P. acnes)of sample-1 in different extraction conditions were evaluated on same concentration, and the group extracted at 25 and $40^{\circ}C$ showed 16 times higher than methyl paraben ($2,500{\mu}g/mL$). In conclusion, 85% ethanol extracts of G. uralensis extracted at $40^{\circ}C$ for 6 h showed the highest antioxidant and antibacterial activity. These results indicate that the extraction condition is important to be optimized by comprehensive evaluation of extraction yield with various conditions, yield of active component, and activity test with concentrations, and activity of 100% extract, for manufacturing process of products.

• Korean Journal of Food Science and Technology
• /
• v.45 no.5
• /
• pp.583-589
• /
• 2013

We investigated the delay of kimchi fermentation by the addition of plant extracts. Fifteen plant extracts were screened for inhibitory activity aginst Lactobacillus plantarum by using an agar well diffusion assay, and determined the minimal inhibitory concentration (MIC) and minimal lethal concentration (MLC) were determined. The lowest MIC for grapefruit seed extract (GFSE; 0.0313 mg/mL) was determined, followed by Caesalpinia sappan L. extract (CSLE; 0.25 mg/mL), and oregano essential oil (OREO; 1.0 mg/mL). GFSE, CSLE, and OREO were individually added to kimchi, and incubated the samples at 10 for up to 20 days. Results showed that the addition of GFSE (0.3 and 0.5%), CSLE (0.1, 0.3, and 0.5%), or OREO (0.5 and 1.0%) led to a significant increase in the pH of kimchi, and also a significant reduction in the numbers of lactic acid bacteria. Taken together, the addition of natural antimicrobial agents can delay kimchi fermentation.