• Journal of Life Science
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• v.18 no.6
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• pp.776-781
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• 2008

To develop natural food preservatives, methanol and water extracts were prepared from the Suaeda maritima and their antibacterial activities were examined against 12 microorganisms which were food borne pathogens bacteria, food poisoning microorganisms and food-related bacteria. Methanol extracts exhibited antibacterial activities for the 5 Gram positve and 7 Gram negative bacteria by agar diffusion method, The antibacterial activities and cell growth inhibition were investigated on each strain with the different concentrations of Suaeda maritima extracts. Antibacterial activities were shown in root, stem, furit extracts of Suaeda maritima. However stem and fruit extracts showed weak antibacterial activity against the tested microorganisms. Root extracts showed the highest antibacterial activities against microorganisms tested, such as Bacillus cereus,Bacillus subtilis, Vibrio parahaemolyticus, Staphylococcus aureus. The highest antibacterial activity against bacteria test was found in the methanol extract.

• Applied Biological Chemistry
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• v.40 no.6
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• pp.514-518
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• 1997

In order to investigate the possible use of spices as natural preservatives) antimicrobial activities of garlic and ginger, representative spices, were examinated. Distilled components of garlic and ginger were also analyzed. Each extract of garlic was more suppressive on the growth of Gram negative bacteria than that of Gram positive bacteria. Extracts of garlic were showed effective suppressions on the growth of yeasts. Of the extracts of garlic, ether extract was highest among antimicrobial activities. In the case of ginger, ether extract of ginger was effective for growth inhibition of tested bacteria. Distilled components of garlic and ginger were extracted by simultaneous steam distillation extraction apparatus. The concentrates were analyzed with GC/MSD and Kovat's retention index and identified 13 components and 21 components respectively. Distilled components of garlic and ginger were full of sulfur compounds and hydrocarbons, respectively. di-2-Propenyl disulfide, methyl 2-propenyl disulfide, 2-vinyl-4H-1,3-dithiirane and 3,3'-thiobis-1-propene were major principal aroma compounds in garlic. ${\alpha}-zingibirene$, ${\beta}-phellandrene$, ${\beta}-sesquiphellandrene$ and camphene were major principal compounds in ginger.

• Korean Journal of Food Science and Technology
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• v.34 no.4
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• pp.652-660
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• 2002

To develop natural food preservatives for extending the shelf-life of jeotkal (salted and fermented seafood), antimicrobial substances were extracted from 32 types of medicinal herbs and edible plants using 95% ethanol. Among the extracts, Glycyrrhizae radix, Curcumae domestica, Galla rhois, and Resina pini showed relatively high inhibitory effects on the growth of the microorganisms isolated from the deteriorated jeotkal. We selected and tested the extract from Recina pini as a natural jeotkal preservative. This ethanol extract was purified partially by adding equal quantity of water, through which 77% of insoluble materials were removed as impurities. In manufacturing modified jeotkal using squid, sucrose and starch syrup were substituted with sorbitol, $glucono-{\delta}-lactone$ was added instead of vitamin C and lactic acid, and sterilized hot pepper was used instead of natural one. The shelf-life of modified jeotkal was prolonged by 4 days compared with the control jeotkal when stored at $20^{\circ}C$, while that of modified jeotkal containing 1.0% partially purified Recina pini extract was prolonged by 6 days compared to the control. The same tests were conducted for the changran (stomach and intestine of Alaska pollack) jeotkal preservation. The shelf-life of the control jeotkal was 24 days, whereas the modified jeotkal and the Resina pini extract-containing modified jeotkal maintained their qualities without changes in microbial and chemical characteristics for 90 days at $20^{\circ}C$ storage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.7
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• pp.1098-1105
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• 2004

In order to develop natural food preservatives, the ethanol and water extracts of the Saururus chinensis Baill were prepared. Antimicrobial activity was examined against 10 kinds of harmful microorganisms. The ethanol and water extracts showed the most active antimicrobial activity against B. subtilis and E. coli. The ethanol extract showed stronger antimicrobial activity than that of the water extract. However, the extracts did not show any antimicrobial activity against lactic acid bacteria and yeast. The minimum inhibitory concentrations (MIC) of ethanol extracts against B. subtilis and E. coli were 5 to 10 mg/mL, respectively. Antimicrobial activity of the ethanol extract was not destroyed at 40-12$0^{\circ}C$ and pH 3∼11. The ethanol extract was fractionated in the order of hexane, diethyl ether, ethyl acetate, and water fractions. The highest antimicrobial activity was found in the diethyl ether fraction.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.9
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• pp.1369-1379
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• 2014

The physicochemical characteristics and antioxidant activities of leaf, stem, and root of ginger (Zingiber officinale R.) were determined. Nutrient composition, reducing sugar, saponin, mineral, heavy metal, total phenolic and total flavonoid contents, and antioxidant activities based on DPPH radical scavenging and FRAP assay were measured. Catechins, gingerols, shogaols, and capsaicin compositions were also determined by HPLC. The contents of water, proteins, fats, carbohydrates, fiber, and ash from ginger root were 6.4, 6.8, 3.2, 65.4, 7.3, and 18.2%, respectively. Crude fiber contents of leaf and stem were 4~5 times higher than those of root (P<0.05), and reducing sugar content of stem was about 3 times higher than those of root. Crude saponin contents were in the order of stem

• Korean Journal of Veterinary Service
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• v.34 no.2
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• pp.167-178
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• 2011

Garlic (Allium sativum L.) has long history of reputed value and actual use for its medicinal, antimicrobial and pesticidal properties. This study was conducted to find possible developments to natural food preservatives and natural antimicrobials from garlic extracts. The antimicrobial activities of raw garlic extract, heat, pH, temperature against pathogenic bacteria were investigated. E. coli, S. Enteritidis, L. monocytogenes, and S. aureus exhibited antimicrobial activities at 20% garlic extract, but no antimicrobial activity was seen in E. faecium. Raw garlic extract and garlic extract heated for 2 min at $95^{\circ}C$ showed strong antimicrobial activities, but the antimicrobial activity of garlic extract heated for 10 min at $95^{\circ}C$ was much less. The antimicrobial activities of 50% garlic extract adjusted pH 4.0~7.0 showed much the same, but the antimicrobial activities decreased at pH 8.0 or higher. The antimicrobial activities by storage $-18^{\circ}C$ of garlic extract showed much the same. When five strains were cultured for 72 hr at $35^{\circ}C$ in the TSB containing 1~10% garlic extract, viable cell number of five strains were decreased to $10^0{\sim}10^4$ CFU/ml even at 1% or 2.5% (E. faecium) after 24 hr, but later increased to $10^4{\sim}10^9$ CFU/ml after 72 hr. When five strains were cultured for 21 day at $4^{\circ}C$ in the TSB containing 1%, 2.5%, 5%, and 10% garlic extract, viable cell number of E. coli, S. Enteritidis, and S. aureus were decreased to $10^3$, $10^0{\sim}10^2$, $10^1{\sim}10^4$ CFU/ml after 21 day, respectively, but L. monocytogenes and E. faecium increased to $10^8$ and $10^6$ CFU/ml after 21 day.

• Journal of Life Science
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• v.29 no.1
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• pp.29-36
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• 2019

We investigated the fermentation conditions for extracts of leave/branches and sap from Korean Dendropanax morbifera (D. morbifera) using Lactobacillus plantarum (L. plantarum) ilchiwhangchil 1785 and L. plantarum ilchiwhangchil 2020. Log growth phase cultured L. plantarum ilchiwhangchil 1785 and L. plantarum ilchiwhangchil 2020 were used for fermentation. The pH and growth of the microorganisms in broth were monitored during the fermentation period. The results revealed that the optimum fermentation conditions for 20 wt% of leave/branches extracts and 1 wt% of sap extract was 2 days incubation at $37^{\circ}C$. The minimum inhibitory concentration (MIC) method and a disk diffusion assay were used to evaluate the antimicrobial activity of the fermented extracts of the leave/branches and sap against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The antimicrobial activity increased in all three strains grown on the medium containing fermented extracts of the leave/branches and sap as compared with that of the strains grown on medium containing non fermented extracts. Furthermore, the antimicrobial activity increased in proportion to the contents of the fermented extracts. Our data suggest that fermented extracts of leave/branches and sap of D. morbifera have applications as natural bio functional materials, such as preservatives, cosmetic materials, and natural packaging materials.

• 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.

• Journal of Food Hygiene and Safety
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• v.37 no.2
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• pp.97-106
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• 2022

Listeria monocytogenes (L. monocytogenes) is one of gram-positive foodborne pathogens with a very high fatality rate. Unlike most foodborne pathogens, L. monocytogenes is capable of growing at low temperatures, such as in refrigerated foods. Thus, various physical and chemical prevention methods are used in the manufacturing, processing and distribution of food. However, there are limitations to the methods such as possible changes to the food quality and the consumer awareness of synthetic preservatives. Thus, the aim of this study was to evaluate the anti-listeria activity of lactic acid bacteria (LAB) isolated from kimchi and characterize the bacteriocin produced by Lactococcuslactis which is one of isolated strains from kimchi. The analysis on the anti-listeria activity of a total of 36 species (Lactobacillus, Weissella, Lactobacillus, and Lactococcus) isolated from kimchi by the agar overlay method revealed that L. lactis NJ 1-10 and NJ 1-16 had the highest anti-listeria activity. For quantitatively analysis on the anti-listeria activity, NJ 1-10 and NJ 1-16 were co-cultured with L. monocytogenes in Brain Heat Infusion (BHI) broth, respectively. As a result, L. monocytogenes was reduced by 3.0 log CFU/mL in 20 h, lowering the number of bacteria to below the detection limit. Both LAB strains showed anti-listeria activity against 24 serotypes of L. monocytogenes, although the sizes of clear zone was slightly different. No clear zone was observed when the supernatants of both LAB cultures were treated with proteinase-K, indicating that their anti-listerial activities might be due to the production of bacteriocins. Heat stability of the partially purified bacteriocins of NJ 1-10 and NJ 1-16 was relatively stable at 60℃ and 80℃. Yet, their anti-listeria activities were completely lost by 60 min of treatment at 100℃ and 15 min of treatment at 121℃. The analysis on the pH stability showed that their anti-listeria activities were the most stable at pH 4.01, and decreased with the increasing pH value, yet, was not completely lost. Partially purified bacteriocins showed relatively stable anti-listeria activities in acetone, ethanol, and methanol, but their activities were reduced after chloroform treatment, yet was not completely lost. Conclusively, this study revealed that the bacteriocins produced by NJ 1-10 and NJ 1-16 effectively reduced L. monocytogenes, and that they were relatively stable against heat, pH, and organic solvents, therefore implying their potential as a natural antibacterial substance for controlling L. monocytogenes in food.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.2
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• pp.242-249
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• 2015

This study examined the antioxidant and antimicrobial activities of 70% ethanol extracts and water extracts of Allium hookeri root. We evaluated the effects of water extracts of A. hookeri root on storage of seasoned pork added with water extracts at $4^{\circ}C$ for 21 days in order to evaluate its potential as a functional food material. A. hookeri root water extracts displayed antioxidant activities (total polyphenol content and DPPH and ABTS radical scavenging activities) that were superior to those of 70% ethanol extracts. The 70% ethanol extracts and water extracts of A. hookeri root showed antimicrobial activities against food-borne Staphylococcus aureus bacteria that were about 1/400 times greater than that of vancomycin. Chemical composition analysis was conducted on pork seasoned with sauce containing 5%, 10%, and 15% water extracts. Moisture and crude ash contents significantly decreased as the amount of water extracts increased (P<0.05), and the highest crude protein content was in the 10% group. Acidity of seasoned pork increased proportionally in the early stages of storage, whereas it significantly decreased as the amount of water extracts increased after day 12 (P<0.05). Although the total number of bacteria in seasoned pork continuously increased during storage, growth of bacteria was significantly restricted as level of A. hookeri root water extracts increased (P<0.05). In the sensory evaluation, pork seasoned with 10% A. hookeri root water extracts showed the highest scores for taste, texture, and overall acceptance (P<0.05). In summary, A. hookeri water extracts display antioxidant and antimicrobial activities that can improve quality characteristics of seasoned pork and have potential as natural preservatives to restrict bacteria growth. Regarding the amount of extracts, 10% was determined to be the most appropriate level to minimize changes in seasoned pork during storage and improve sensory quality.