• Plant Resources
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• v.8 no.2
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• pp.96-102
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• 2005

As part of developing natural food preservatives, the antimicrobial effect of ethanol and water extracts from the Cruciferous vegetable was examined Korean traditional Brassica juncea Coss. was used widely as an ingredient of Kimchi, a natural flavoring and spice for a long time. Antimicrobial activities were examined against 15 microorganisms which were food-born pathogens and/or food poisioning microorganisms and food-related bacteria and yeasts. Ethanol extract from leaf mustard showed an antimicrobial effect in most of the strains used in the present study. The lowest minimum inhibitory concentration (MIC) were seen in Bacillus subtilis and Bacillus natto at 10 mg/ml. MIC of water extract was 40-60 mg/ml for bacteria and yeast. Antimicrobial activity of the ethanol extract was not disappeared by the heating at $121^{\circ}C$ for 15 min and not affected by pH.

• Korean Journal of Medicinal Crop Science
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• v.17 no.5
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• pp.335-340
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• 2009

To evaluate the availability of Cudrania tricuspidata Bureau as a natural source of antimicrobials, the antimicrobial activity of methanol extracts of harvested parts was investigated using the paper disc diffusion method. The extracts from leaves and root bark had broad antimicrobial activity against various bacteria, including Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Streptococcus mutans, Listeria monocytogenes, Enterobacter aerogenes, Enterococcus faecalis, Salmonella choleraesuis subsp. choleraesuis, Vibrio vulnificus, and Pseudomonas aeruginosa and inhibited Bacillus cereus, Staphylococcus aureus, and Listeria monocytogenes, agents of food poisoning especially well. The extract from ripe fruit had a very high antimicrobial activity against Staphylococcus aureus with a 20.2 mm of clear zone at 50 mg/mL sample concentration. These results indicated that Cudrania tricuspidata could be used as new source for developing natural antimicrobial agents.

• Korean Journal of Food Science and Technology
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• v.37 no.1
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• pp.50-54
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• 2005

Antimicrobial activities of ethanol extracts of marta rosemary (Rosemarinus officinalis L.) against Bacillus subtilis and Salmonella typhimurium were investigated under conditions similar to processing of general food materials to develop natural food preservatives. The strongest antimicrobial activities were shown against the tested organisms at pH 7. In B. subtilis, the herbal extract extended the lag phase at low concentrations, and reduced the specific growth rate during logarithmic phase at high concentrations. In S. typhimurium the herbal extract reduced the specific growth rate even at lower concentrations. These trends were obtained at low pHs of culture solution. Antimicrobial substances of herbs were efficiently extracted with low polar solvents. The thermal stability of antimicrobial substances decreased with heating time at $100^{\circ}C$. S. typhimurium was more sensitive to herbal extracts at $100\;and\;121^{\circ}C$ than B. subtilis.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.3
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• pp.374-381
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• 2013

The purpose of this study was to analyze the antioxidant effects and antimicrobial activity of extracts from yacon powder. The total polyphenol contents of yacon powder extracted with methanol was 38.5 mg/g, while extracted with water was 24.0 mg/g. Extractions with methanol were therefore more effective than with water. The total flavonoid contents of yacon powder extracted with methanol was 9.2 mg/g, while that with water was 7.8 mg/g. The electron donating ability of yacon powder extracts, natural antioxidant, and artificial antioxidant at 1.0 mg/mL arranged in order of decreasing concentration were ascorbic acid (98.7%) > BHT (44.7%) > methanol extract (12.1%) > water extract (7.8%). Nitrite-scavenging ability of yacon powder extracted with methanol at pH 1.2 was 13.1%, while that of powder extracted with water at pH 1.2 was 6.8%. And, the hydroxyl radical scavenging activities of yacon powder with methanol at 5 mg/mL was 40.2%. The antimicrobial activity of yacon powder extracted with methanol could be detected on Bacillus cereus ($10,000{\mu}g/disc$) and Staphylococcus aureus ($10,000{\mu}g/disc$).

• Journal of Microbiology and Biotechnology
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• v.32 no.5
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• pp.594-601
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• 2022

This study evaluated the biological properties of lemongrass (Cymbopogon citratus) extracts. The EtOAc extract of lemongrass had DPPH, TEAC, and nitric oxide-scavenging activity assay results of 58.06, 44.14, and 41.08% at the concentration of 50, 10, and 50 ㎍/ml, respectively. The EtOAc extract had higher elastase and collagenase inhibitory activities than the 80% MeOH, n-hexane, BuOH, and water extracts and comparable whitening activity toward monophenolase or diphenolase. Also, the EtOAc fraction had higher lipase inhibitory and antimicrobial activities against Cutibacterium acnes among extracts which is known to an important contributor to the progression of inflammatory acne vulgaris, and an opportunistic pathogen present in human skin. Total phenolic and flavonoid concentrations in the EtOAc extract were 132.31 mg CAE/g extract and 104.50 mg NE/g extract, respectively. Biologically active compounds in lemongrass extracts were analyzed by LC-MS. This study confirms that lemongrass extracts have potential use as cosmetic skincare ingredients. Thus, lemongrass can be considered a promising natural source of readily available, low-cost extracts rich in antioxidant, skincare, and antimicrobial compounds that might be suitable for replacing synthetic compounds in the cosmeceutical industry.

• Journal of Life Science
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• v.20 no.4
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• pp.589-596
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• 2010

We investigated antimicrobial activities of various pine (Pinus densiflora) needle extracts against antibiotic resistant strains of Staphylococcus aureus. Hot water extract showed the highest antimicrobial activity against normal and methicillin resistant Staphylococcus aureus (MRSA), however, it exhibited no antimicrobial activity against penicillin resistant S. aureus (PRSA). Hot water-hexane (HWH), hot water-ethanol (HWE), hexane, and ethanol extracts showed antimicrobial activity against S. aureus, PRSA and MRSA. Minimum inhibitory concentrations (MIC) of HWH, HWE, hexane, and ethanol extracts were 0.05, 0.05, 0.5 and 5 mg/ml, respectively, and HWH and HWE extracts showed the strongest antimicrobial activity among these extracts. Antimicrobial activities of pine needle extracts were stable after heating at $121^{\circ}C$ for 20 min. These results suggested that pine needle extracts can be used as an effective natural antimicrobial agent for food and medical industries.

• Food Science and Preservation
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• v.21 no.3
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• pp.427-433
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• 2014

Ethanol and hot water extracts were prepared from Lindera obtusiloba Blume (LO) and Zanthoxylum piperitum DC (ZP) and used to evaluate their antimicrobial activities and thermal stability against six foodborne pathogens (3 gram-positive and 3 gram-negative bacteria). The antimicrobial activities were assessed using the agar diffusion method, and the thermal stabilities of extracts were examined after heat treatment at 60, 70, 80, and $100^{\circ}C$ for 10 min. The zones of inhibition by the LO extract or the ZP extract of the tested microorganisms were in the range of 21-30 mm and 19-25 mm, respectively, at 100 mg/mL concentrations. The 60% ethanol extract and the hot water extracts from LO showed the strongest antimicrobial effects against MRSA and Staphylococcus aurues, respectively. For the extract from ZP, the strongest antimicrobial effect was shown against S. aurues by 60% ethanol, and the weakest antimicrobial effect was shown against E. coli by the hot water extracts. The ZP extracts showed that the gram-positive bacteria were more sensitive than gram-negative bacteria. For the thermal stability of the extracts, the antimicrobial effects stabilized after heat treatment. Overall, the data suggest that the extracts have a potential for application in various food products for which a natural antimicrobial additive is desired.

• Korean Journal of Food Science and Technology
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• v.34 no.4
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• pp.700-709
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• 2002

To develop a natural food preservatives from medicinal herbs (62 species), antimicrobial test was performed with hot water and ethanol extracts against Escherchia coli, Listeria monocytogens and Candida albicans by paper disk method. And its result as a first screening test, 7 kinds of medicinal herbs were selected, and more precise analysis was conducted at last 3 kinds of medicinal herbs was finally selected. Therminalia chebula Retz and Rhus javanica has a broad antimicrobial spectrums and has a low MIC values. In growth inhibition test, they showed a very strong antimicrobial activity aganist Listeria monocytogens. If there has a elaborate approaches in its characteristics and properties, some good result must followed in making a powerful natural antimicrobial preservatives.

• Microbiology and Biotechnology Letters
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• v.25 no.3
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• pp.293-297
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• 1997

To develope natural food preservatives of pine needle (Pinus densiflora Seib et Zucc.) extract, pine needle sap, ethanol and ether extracts were prepared for investigation of antimicrobial activities against food-related bacteria and yeasts. All extracts exhibited growth inhibiting activities for most of microorganisms tested. However, in general, growth inhibiting activities were higher in ethanol extract than in sap or ether extract. Minimum inhibitory concentrations (MIC) of ethanol extract for Lactobacillus casei, Pseudomonas aeruginosa or Escherchia coli were as low as 0.1 mg/ml, whereas MIC of sap or ether extract for most bacteria and yeasts were 0.25-0.8mg/ml, indicating that the ethanol extract showed the antimicrobial activity by 2.5 $\sim$8 times higher than the sap and ether extract. The antimicrobial activity of the ethanol extract was reduced by heating or alkali treatment. Moreover, growth of Pseudomonas aeruginosa was completely inhibited within 24 hours by the addition of at least 50ppm of ethanol extract. These findings suggest that pine needle, specially the ethanol extrat may play a role for natural food preservatives.

• Journal of Korean society of Dental Hygiene
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• v.17 no.3
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• pp.493-504
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• 2017

Objectives: This study aimed to find out the antimicrobial activities of Ramaria botrytis (Fr.) extracts against oral pathogens. Methods: The antimicrobial activities of Ramaria botrytis (Fr.) extracts were evaluated against oral pathogens by the disc diffusion assay, and the minimum inhibitory concentrations (MICs) of ethyl acetate extracts were determined by broth dilution method. The strains used in this study were Staphylococcus aureus, Streptococcus mutans, Streptococcus sanguinis, Streptococcus sobrinus, Streptococcus anginosus, Streptococcus ratti, Streptococcus criceti, Actinomyces israelii, Actinomyces viscosus and Aggregatibacter actinomycetemcomitans. Results: The ethyl acetate extract of Ramaria botrytis (Fr.) effectively inhibited the growth of oral bacteria compared with acetone or ethanol extract. The ethyl acetate extract exhibited MIC values ranging from 3.75 to 15.00 mg/ml, and it showed antimicrobial activity against both Gram-positive and negative oral bacteria. Conclusions: The ethyl acetate extracts from Ramaria botrytis (Fr.) showed the antimicrobial activities against ten oral bacteria. Thus, the extract of Ramaria botrytis (Fr.) may be considered as an effective natural antimicrobial agent for the prevention of oral pathogens.