• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.751-756
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• 1999

The inhibitory effect of antibiotics on growth of lactobacillus, streptococcus and bifidobacteria was examined to develop the selective media to isolate and enumerate bifidobacteria from the fermented foods containing various lactic bacteria. The growth of lactic bacteria was inhibited seriously but that of bifidobacteria was not inhibited by gentamycin or ripampicin at the concentration of more than $100\;{\mu}g/mL$. However lactic bacteria did not grow in MRS broth containing $50\;{\mu}g/mL$ of ampicillin and the growth inhibition of bifidobacteria occurred. The growth inhibition of bifidobacteria was more severe than lactic bacteria in $100\;{\mu}g/mL$ of fosfomycin. Therefore, the MRS medium containing $80\;{\mu}g/mL$ of neomycin sulfate, $50\;{\mu}g/mL$ of gentamycin, $50\;{\mu}g/mL$ of rifampicin, $15\;{\mu}g/mL$ of nalidixic acid and $3\;{\mu}g/mL$ of lithium chloride was concluded selective for bifidobacteria, but restrictive for the other lactic bacteria present in Kimchi and cheese.

• Microbiology and Biotechnology Letters
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• v.32 no.3
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• pp.249-255
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• 2004

Chinese cabbage ('Baechu') Kimchi was fermented at the three different temperatures right after it was prepared. Samples were taken everyday for measuring bacterial populations, pH, and titratable acidity through the whole periods of fermentation up to 50 days. pH values and developed acidity were significantly affected by the fermenting temperatures of 4, 10, and $20^{\circ}C$, suggesting that different bacterial flora has been established by the temperatures exposed. The modified MRS agar containing vancomycin (300 $\mu$g/mL) was used for isolating the vancomycin-resistant LAB strains and 127 isolates were finally obtained. Of the LAB isolates, 13 isolates were subjected to the identification experiments based on the biochemical characteristics and the molecular-typing approach, an ITS-PCR, whether they belong to the genus Leuconostoc or not. The data obtained from API 50 CHL kit resulted that six isolates were identified as the members of Leuconostoc and six as Lactobacillus brevis strains except for a single isolate YKI 30-0401, which was not able to be identified because its biochemical traits were not matched to the database of API 50 CHL kit. It was noted that some isolates were distinct in a couple of some biochemical characteristics compared with those of the reference Leuconostoc species. To overcome the limitations experienced in the commercial identification products above, an ITS-PCR experiment was also conducted for the isolates, resulting that eight isolates belong to Leu. mesenteroides ssp. mesenteroides or dextranicum with a single band of 564 bp, and four to L. brevis strains. The ITS-PCR profiles clearly differentiated the closely-related LAB isolates for which same results were obtained by the biochemical method. This molecular approach, however, failed to produce the amplicons for the YKI 20-1003, leaving the strain unidentified. Judging from the identification data obtained in the Kimchi fermented at $4^{\circ}C$ or $10^{\circ}C$, Leuconostoc spp. including Leu. mesenteroides/dextranicum were likely predominant species in the earlier stage and L. brevis occurred at the high level through the whole period. By contrast, L. brevis, as one of the major flora, possibly lead the fermentation from the beginning in the Kimchi fermented at $20^{\circ}C$.}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.3
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• pp.549-552
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• 2004

A simple, efficient and accurate method was developed for the simultaneous determination of non-permitted oil soluble colorants (sudan I, II, III and IV) in foods. The identification has been carried out for sudan colorants by TLC as well as HPLC with photodiode array (PDA) detection. Separation of sudan colorants was achieved within 20 min by a gradient elution with water and acetonitrile as eluents. Sudan colorants showed good linear relationships in the range of 0.1 ～ 100 $\mu\textrm{g}$/mL. The correlation coefficients of the calibration curve for sudan colorants exceeded 0.999. The detection limits (signal-to-noise ratio 3 : 1) for sudan I, II, III and IV were 0.01, 0.01, 0.02 and 0.02 $\mu\textrm{g}$/mL, respectively. This method has been successfully applied to the analysis of red pepper powder, Kimchi and Kakdugi, and the average recoveries for real samples ranged from 83.02% to 104.3%.

• Nutrition Research and Practice
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• v.12 no.2
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• pp.93-100
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• 2018

BACKGROUND/OBJECTIVE: Oxidative stress plays a key role in neuronal cell damage, which is associated with neurodegenerative disease. The aim of present study was to investigate the neuroprotective effects of perilla oil (PO) and its active component, alpha-linolenic acid (ALA), against hydrogen peroxide $(H_2O_2)$-induced oxidative stress in SH-SY5Y neuronal cells. MATERIALS/METHODS: The SH-SY5Y human neuroblastoma cells exposed to $250{\mu}M$ $H_2O_2$ for 24 h were treated with different concentrations of PO (25, 125, 250 and $500{\mu}g/mL$) and its major fatty acid, ALA (1, 2.5, 5 and $25{\mu}g/mL$). We examined the effects of PO and ALA on $H_2O_2$-induced cell viability, lactate dehydrogenase (LDH) release, and nuclear condensation. Moreover, we determined whether PO and ALA regulated the apoptosis-related protein expressions, such as cleaved-poly ADP ribose polymerase (PARP), cleaved caspase-9 and -3, BCL-2 and BAX. RESULTS: Treatment of $H_2O_2$ resulted in decreased cell viability, increased LDH release, and increase in the nuclei condensation as indicated by Hoechst 33342 staining. However, PO and ALA treatment significantly attenuated the neuronal cell death, indicating that PO and ALA potently blocked the $H_2O_2$-induced neuronal apoptosis. Furthermore, cleaved-PARP, cleaved caspase-9 and -3 activations were significantly decreased in the presence of PO and ALA, and the $H_2O_2$-induced up-regulated BAX/BCL-2 ratio was blocked after treatment with PO and ALA. CONCLUSIONS: PO and its main fatty acid, ALA, exerted the protective activity from neuronal oxidative stress induced by $H_2O_2$. They regulated apoptotic pathway in neuronal cell death by alleviation of BAX/BCL-2 ratio, and down-regulation of cleaved-PARP and cleaved caspase-9 and -3. Although further studies are required to verify the protective mechanisms of PO and ALA from neuronal damage, PO and ALA are the promising agent against oxidative stress-induced apoptotic neuronal cell death.

• Journal of Microbiology and Biotechnology
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• v.19 no.2
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• pp.178-186
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• 2009

To examine their potential as probiotics, acid and bile tolerance, antibiotics resistance, adhesion capacity to Caco-2 and HT-29, and antibacterial activity, of LAB isolated from Korean fermented foods such. as dongchimi, kimchi, Meju, and doenjang were assayed against foodborne pathogenic bacteria. DC 55, DC 136, DC 222, KC 21, KC 24, KC 34, KC 43, KC 117, MJ 54, MJ 301, SP 33, and SP 170 strains were resistant to acid and bile conditions. In particular, DC 55, DC 136, KC 24, KC 43, and MJ 301 strains were highly resistant to higher than 20 ${\mu}g/ml$ concentrations of vancomycin, streptomycin sulfate, or amoxicillin, whereas, DC 222, KC 21, KC 34, KC 117, MJ 54, and SP 33 strains were susceptible to lower than 2 ${\mu}g/ml$ concentrations of those antibiotics. The adhesion to HT-29 and Caco-2 cells varied with the strains tested in a strain-dependent manner. The highest level of adhesion was observed with DC 55, KC 21, KC 24, and MJ 301 strains, having higher than 50% of adhesion to HT-29 or Caco-2 cells. In addition, Staphylococcus aureus was the most sensitive to KC 21, showing an inhibition of about 70%, and the antibacterial activity of KC 21 against S. aureus resulted most likely from both organic acids and bacteriocin. Based on its phenotypic characteristics and utilization of various sugars, the KC 21 strain was identified as Lactobacillus plantarum.

• Journal of Integrative Natural Science
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• v.10 no.3
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• pp.154-161
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• 2017

An antimicrobial peptides-producing Bacillus strain CBS73 was isolated from fermented food (kimchi) that produces low-molecular-weight proteins with broad-spectrum antimicrobial activity. Our goal was to explore the therapeutic potential of antimicrobial substances produced by Bacillus species. Peptide CBS73 was purified from Bacillus subtilis subsp. subtilis with identity of 99.79%. It was found to be stable at pH 4.0-10.0 and temp $20-60^{\circ}C$. A protein band around 5.2 kDa was detected in tricine-SDS-PAGE and band was confirmed by MALDI-TOF test. Peptide CBS73 showed antimicrobial activity against MDR bacteria. The minimal inhibitory concentration (MIC) of peptide CBS73 for vancomycin-resistant S. aureus (VRSA), vancomycin resistant Enterococci (VRE) and Salmonella typhimurium ranged from $10-40{\mu}g/mL$. The antioxidant activity of peptide CBS73 was measured by DPPH scavenging, reducing power activity and total phenolic content. Cell viability and NO production result showed less cytotoxic effect upto $12{\mu}g/mL$. Peptide CBS73 could be a promising antimicrobial agent for clinical application.

• Nutrition Research and Practice
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• v.5 no.6
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• pp.548-552
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• 2011

The purpose of this study was to estimate the daily manganese (Mn) intake of Korean children. This study was done using a three-day dietary intake survey of 257 Korean children (boys 123; girls 134). The Mn intake values were calculated based on a database that provides the Mn content of the frequently consumed Korean foods, alongside the food composition table provided by the Korean National Rural Living Science Institute. The average age, height, weight and body mass index of our subjects were 11.9 years, 155.4 cm, 48.9 kg and 20.2 kg/$m^2$ in boys and 11.9 years, 154.1 cm, 43.5 kg and 18.3 kg/$m^2$ in girls. The average daily energy intakes were 2,249.2 kcal in boys and 2,044.5 kcal in girls. Boys consumed significantly more Mn than girls, based on intake estimates of $4,585.3{\mu}g$ (117.6% of adequate intake) and $4,029.3{\mu}g$ (117.1% of adequate intake), respectively (P < 0.001). Boys had a Mn intake of $2,041.1{\mu}g$ per 1,000 kcal of energy consumption, whereas for girls this was at $1,983.9{\mu}g$ per 1,000 kcal. Neither group exceeded the tolerable upper intake level for Mn. The major food groups which contributed to Mn intake in our subjects were cereals (50.8%), vegetables (21.0%), seasonings (8.9%), and pulses (7.7%). Notably, boys derived a higher Mn intake through cereals and vegetable than did girls (P < 0.001, P < 0.05). The key food sources of Mn, in descending order, were rice, soybean curd, kimchi, black rice and cereals. We propose that the results of our study may be used as a basis for follow-up studies that examine the Mn intake of children.

• Journal of Dairy Science and Biotechnology
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• v.37 no.2
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• pp.115-128
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• 2019

Lactic acid bacteria obtained from traditional Kimchi were selected on the basis of their caseinolytic activity and lactose usability and examined for availability as a starter in probiotic activity. Thirty-two strains were selected as lactic acid producing bacteria in BCP agar, and two strains (KC23 and KF26) with more than 90% resistance for both acid and bile salts were selected. The two strains were identified as L. plantarum (KC23) and L. paracasei (KF26) by API 50 CHL system and 16S rRNA sequence analysis. L. plantarum (KC23) was finally selected based on its biochemical characteristics for lactose and raffinose usability. Free tyrosine content increased rapidly in 10% skimmed milk medium, from $24.1{\mu}g/mL$ after 8 h to $43.9{\mu}g/mL$ after 16 h. Additionally, the caseinolytic clear zone of 12 mm of L. plantarum (KC23) was greater than the 9 mm zone of commercial L. acidophilus CSLA. The bacterium exhibited mesophilic growth and yielded $8.9{\times}10^8CFU/mL$ when incubated at $37^{\circ}C$ for 12 h at pH 4.25. Moreover, L. plantarum KC23 exhibited antibacterial activity as it formed a clear zone of 8-13 mm for the 5 pathogens. Adherent activity was 2.23 fold higher than that of LGG. The acidity of 10% skimmed milk fermented for 12 h was 0.74%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.3
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• pp.327-334
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• 2017

Water and 75% ethanol extracts were prepared from defatted green tea seeds and evaluated for their anti-yeast activities. The antimicrobial activities of defatted green tea seed extracts (DGTSEs) were tested against food-spoilage bacteria, yeasts, and molds. DGTSEs exhibited antimicrobial activities with minimum inhibitory concentrations of $39{\sim}1,250{\mu}g/mL$ against three bacteria, two molds, and all tested yeast strains. Ethanol extract showed higher antimicrobial activity than water extract. The stability of anti-yeast activities of DGTSEs was examined under different conditions of temperature, pH, and NaCl concentrations. The anti-yeast activities of DGTSEs were stable at pH 3~9, 0~20% NaCl, and $100^{\circ}C$ for 30 min. However, anti-yeast activities of DGTSEs decreased upon heating at $70^{\circ}C$ for 24 h or $121^{\circ}C$ for 15 min. DGTSEs were applied to food models to determine their inhibitory effects on yeast film formation. Water and 75% ethanol extracts were effective in preventing yeast film formation at concentrations more than 156 and $39{\mu}g/mL$ in soy sauce, 156 and $78{\mu}g/mL$ in pickle sauce, and 78 and $39{\mu}g/mL$ in kimchi, respectively.

• Korean Journal of Pharmacognosy
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• v.47 no.1
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• pp.55-61
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• 2016

Antioxidant effects and nuclear factor E2-related factor-2 (Nrf-2) signal pathway of methanol extract and 4 fractions [n-hexane, methylene chloride, ethyl acetate (EtOAc), and n-butanol fractions] from Petasites japonicus were investigated. The EtOAc fraction showed highest polyphenol and flavonoid contents among other fractions. In addition, EtOAc fraction showed stronger scavenging activity against superoxide anion radical than other fractions. Furthermore, we investigated antioxidants effects of the EtOAc fraction under cellular system using $LLC-PK_1$ cells. The EtOAc fraction dose-dependently increased the antioxidant protein expressions of heme oxygenase 1 (HO-1) and thioredoxin reductase 1 (TrxR1) known to be involved in oxidative stress, through activation of Nrf-2. The treatment of EtOAc fraction ($100{\mu}g/mL$) led to the elevation of the high expression of Nrf-2-dependent factor such as HO-1 and TrxR1. These results indicated that the EtOAc fraction of P. japonicus showed high antioxidant activity by regulation of Nrf-2 signaling pathway.