• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.11
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• pp.1382-1388
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• 2008

Antimicrobial activities of green tea extracts used for coarse tea were investigated by disc diffusion method using eight different bacteria. Among the green tea extracts, the 70% ethanol extract demonstrated the strongest antimicrobial activities against Vibrio parahemolyticus (V. parahemolyticus) and Staphylococcus aureus (S. aureus) and thus was further fractionated. Among these fractions, the ethyl acetate fraction showed the strongest antimicrobial activities against V. parahemolyticus, S. aureus, Bacillus subtilis (B. subtilis), and Streptococcus mutans (S. mutans). These activities exceeded that of all extracts and fractions tested in this study. Interestingly, although green tea extracts showed significant antimicrobial activity against Micrococcus luteus (M. luteus), once fractionated, the ethyl acetate fraction did not show any antimicrobial activity against M. luteus. MICs of the ethyl acetate fraction were $5\;\;{\mu}L$/disc against B. subtilis and $3\;{\mu}L$/disc against S. aureus, S. mutans and V. parahaemolyticus. 90% inhibition of B. subtilis was observed with 0.05% ethyl acetate fraction but S. mutans needed over 0.1% ethyl acetate fraction to exhibit the same inhibition as B. subtilis. Antimicrobial activities of ethyl acetate fractions were reduced around 10% by thermal treatment at $121^{\circ}C$ for 20 min. All the results suggest that the 70% ethanol extract as well as the ethyl acetate fraction from green tea used for coarse tea could be further developed into a natural antimicrobial agent.

• Korean Journal of Food Science and Technology
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• v.40 no.5
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• pp.485-490
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• 2008

In this study, organic tea leaves were characterized with the aim of developing an organic beverage process. The green tea leaves grown using organic farming techniques were collected in Haenam, Korea. Catechins in green tea leaves were extracted by chloroform and ethyl acetate and these were then analyzed quantitatively and qualitatively by HPLC (high pressure liquid chromatography). The color and pH values of the green tea extracts were also measured. The catechin levels of April-harvested, May-harvested and June-harvested, semi-fermented leaves at 0.5% were 66.24, 29.19, 57.11, and 5.27 ${\mu}g/mL$, respectively. Among the detected catechins, the level of (-)-epigallocatechin gallate was the highest while that of (-)-epigallocatechin was not detected. The June-harvested leaves were selected as raw material for development of the green tea beverage, based on the levels of catechins, economic viability and yield of tea extract. As the level of extract increased, the levels of catechins of 0.1, 0.2, 0.5% also increased by 1.5, 11.78 and 41.01 times. From the results of the sensory evaluation of June-harvested leaf-extract, the sensory score of color was the highest in 0.1%, while the flavor and overall quality were the highest in 0.2%.

• The Korean Journal of Food And Nutrition
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• v.25 no.2
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• pp.233-238
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• 2012

Diarrheal diseases constitute one of the major causes of morbidity and mortality in infants and young children globally. One of the main microorganisms causing diarrheal diseases is Campylobacter jejuni. For treatment of these diseases, Portulaca oleracea has been widely used as a folk remedy for a long time. This study was performed to investigate the antimicrobial activity of P. oleracea against gastroenteritis pathogens including C. jejuni. P. oleracea was extracted with petroleum ether, chloroform, ethylacetate, methanol, and hot water. The antimicrobial activity of the P. oleracea extracts was determined using the paper disc method, minimum inhibitory concentration, and the liquid culture method. The 10 $mg/m{\ell}$ ethylacetate extract showed the strongest antimicrobial activity against Salmonella typhimurium, Salmonella enteriditis, and Shigella spp.. The hot water extract from P. oleracea showed the highest anti-microbial activity against C. jejuni at 10~20 $mg/m{\ell}$. The hot water extract of P. oleracea retarded the growth of C. jejuni for 36 hr at $42^{\circ}C$.

• Korean Chemical Engineering Research
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• v.48 no.6
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• pp.741-746
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• 2010

Phospholipids were recovered from squid viscera residues by ethanol extraction after supercritical carbon dioxide($SCO_2$) extraction and from squid viscera was not processed $SCO_2$ by various organic solvent extraction. $SCO_2$ extraction were performed at $45^{\circ}C$ and 20 MPa for removal of non polar lipid molecules from freeze dried squid viscera sample. Phospholipids were extracted from freeze dried squid viscera sample by chloroform, hexane, methanol, and ethanol and from $SCO_2$extracted squid viscera sample by ethanol. The pH was fixed at 5.7 for all phospholipids extraction conditions. Phospholipid classes were analyzed by HPLC equipped with evaporative light scattering detector (ELSD). Phosphatidyl choline(PC) extracted by ethanol from $SCO_2$ extracted residues was higher than that of extracted by ethanol from squid viscera. But phosphatidyl ethanolamine(PE) and phosphatidic acid(PA) were extracted higher percentage in raw squid viscera. The fatty acid compositions in phospholipids extract by ethanol extract from $SCO_2$ extracted residues were analyzed by gas chromatography(GC). Docosahexanoic acid(DHA) was found in highest percentage in phospholipid extract.

• Food Science and Preservation
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• v.11 no.4
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• pp.455-460
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• 2004

This study was conducted to determine the yield, free radical scavengering effect and total phenol contents of various solvent fractions on the crude and defatted grape seed extract during storage. The optimal condition for the extraction yield, free radical scavengering effect and total phenol contents was $90\%$ ethanol for 6 hour at $70^{\circ}C$. The extraction yield for crude and defatted grape seed at optimal condition was $8.9\%\;and\;9.16\%$, respectively. Also, the strongest free radical scavengering effect with $41.52\;{\mu}g/mL$ was observed in $95\%$ ethanol of defatted grape seed extracted for 6 hour at $70^{\circ}C$. Similar result was observed in total phenol contents of defatted grape seed. The ethyl acetate fraction obtained from ethanol extract of defatted grape seed showed the strongest RC50($12.35\;{\mu}g/mL$) compared to other organic fractions. Free radical scavengering effect of crude and defatted grape seed extracts treated with alkali condition(pH 10) was reduced compared to that of acidic condition(pH 2) during storage far 1 month at $50^{\circ}C$. Overall, more stronger free radical scavengering effect and higher total phenol contents in defatted grape seed extracts was observed than that of crude grape seed.

• Food Science and Preservation
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• v.11 no.2
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• pp.214-220
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• 2004

This study was carried out to determine the antioxidative, antimutagenic, and anticancer effects of functional food manufactured from fermented soybean(FFMFS) using DPPH free radical donating method, Ames test and cytotoxicity, respectively. FFMFS extracted with ethanol and then further fractionated to n-hexane, chloroform, ethyl acetate(EtOAc), butanol and water, stepwise. Among five fractions, the EtOAc fractions showed highest electron donating activities (31.6 $\mu\textrm{g}$/mL). The inhibition rate of ethanol extract(200 $\mu\textrm{g}$/plate) of FFMFS in the S. typhimurium TA100 strain showed 84.8% against the mutagenesis induced by MNNG. In addition, the suppression of EtOAc fractions with same concentration of FFMFS the S. typhimurium TA98 and TA100 strains showed 88.7% and 92.8% inhibition against Trp-P-l, respectively. The cytotoxic effects of FFMFS against the cell lines with human lung carcinoma(A549), human gastric carcinoma(AGS) and human breast adenocarcinoma(MCF-7) were inhibited with the increase of the extract concentration. The treatment of 1.0 mg/mL FFMFS of EtOAc fraction showed strong cytotoxicities of 84.5%, 88.7% and 85.6% against A549, AGS and MCF-7, respectively.

• Food Science and Preservation
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• v.9 no.2
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• pp.234-239
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• 2002

To study the potential of the chestnut(Castanea crenata S.) leaves, as raw materials for functional food and medicine, chemical components, antioxidative and antimicrobial activities were carried out. The proximate composition was composed of total sugar 11.95%, crude fat 11.50%, crude fiber 10.11%, crude protein 7.50% and ash 1.79% and the components of major minerals were Ca 215.7 mg%, 196.6 mg%. The content of vitamin C wag 12.5 mg% and free sugar was composed of glucose 3.33%, fructose 0.25% and sucrose 0.022%. The major fatty acids in leaves of chestnut were composed of linoleic acid and the amounts of those showed 37.88% area percent. The major amino acids of chestnut leaves were glutamic acid(295.4 mg%), proline(285.7 mg%), aspartic acid(245.5 mg%), arginine(240.8 mg%), phenylalanine(237.4 mg%) and leucine(230.6 mg%). The ratio of essential/total amino acid was 48.3%. Methanol extract and ethyl acetate fraction showed stronger activity of the hydrogen donating activities, each of 72.52 % and 84.12 %, respectively. In solvent extracts using methanol, ethanol, ethyl acetate, chloroform and hexane, methanol extract showed the most effective antimicrobial activities. Antimicrobial activities of ethyl acetate fraction of methanol extract was higher than those of other fractions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.2
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• pp.211-216
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• 2003

This study was carried out to determine the antioxidative, antimutagenic, and anticancer effects of Rhodiola sachalinensis root using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical donating method, Ames test and cytotoxicity, respectively. Rhodiola sachalinenis root were extracted with ethanol and then further fractionated to n-hexane, chloroform, ethyl acetate (EtOAc), butanol and water, stepwise. Among five fractions, the Etohc fractions showed the highest electron donating activities (14.3 $\mu$g/mL). The inhibition rate of ethanol extract (200$\mu$g/plate) of Rhodiola sachalinensis root in the S. typhimurium TA100 strain showed 89.1% inhibition against the mutagenesis induced by MNNG. In addition, the suppression of EtOAc fractions with same concentration of Rhodiola sachalinensis root in the S. typhimurium TA98 and TAI00 strains showed 89.7% and 91.5% inhibition against 4NQO, respectively. The suppressions under the same condition against B($\alpha$)P and Trp-P-1 in the TA98 and TA100 strains were 94.2% and 95.7%, and 92.3% and 93.8%, respectively. The cytotoxic effects of Rhodiola sachalinensis root against the cell lines with human lung carcinoma (A549), human hepatocellular carcinoma (HepG2), human gastric carcinoma (AGS) and human breast adenocarcinoma (MCF-7) were inhibited with the increase of the extract concentration. The treatment of 1.0 mg/mL Rhodiola sachalinensis root of EtOAc fraction showed strong cytotoxicities of 90.5%, 81.5%, 92.2% and 82.6% against A549, HepG2, AGS and MCF-7, respectively.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1654-1660
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• 1999

The free phenolic acid fraction of the chloroform extract from 75% ethanol extract of Rhus verniciflua STOKES (RCF) showed stronger antioxidative activity than BHT, BHA and ${\delta}-tocopherol$ at the same concentration. RCF components were isolated and identified by silica gel column chromatography, thin layer chromatography, mass spectrometer and $^1H-NMR\;and\;^{13}C-NMR$. The antioxidative activity was confirmed by electron donating activity, Rancimat method and thiobarbituric acid test in liposome system. RCF-11 could be further separated into three fractions. The antioxidative active compounds were purified and identified as gallic acid, butin and butein. The RCF-13 was purified and identified as sulfuretin.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.11
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• pp.1580-1588
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• 2016

The 70% ethanol extract from Adenophora triphylla showed a strong antioxidant effect and reduced cytotoxicity of $H_2O_2$ in SK-N-SH cells. The chloroform fraction from A. triphylla extract (AT-CH) among the six fractions showed strong DPPH radical and intracellular reactive oxygen species (ROS) scavenger effects and the highest protective effect against $H_2O_2$-induced SK-N-SH cell death. Bioactivity compounds were purified from AT-CH, and the chemical structures of the compounds were determined as ${\beta}$-sitosterol and daucosterol on the basis of $^1H-NMR$, $^{13}C-NMR$, and EI mass spectra. ${\beta}$-Sitosterol and daucosterol also had protective effects against oxidative stress in SK-N-SH cells. Phospho-p38 MAPK levels were elevated by $H_2O_2$ but were inhibited by treatment with AT-CH and phytosterols (${\beta}$-sitosterol and daucosterol) isolated from AT-CH. These results suggest that AT-CH has brain neuroprotective effects against oxidative stress ($H_2O_2$) by inhibiting activation of p38 pathways and scavenging intracellular ROS.