• Korean Journal of Organic Agriculture
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• v.24 no.1
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• pp.73-85
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• 2016

This study was carried out to allelopathic effects of aqueous extracts on Coronopus didymus in order to investigate the competitive dominant in plant ecosystem and possibility application in natural herbicide. Number of species and species diversity for close to patch of C. didymus was decreased gradually site #1 (7, 1.76), site #2 (5, 1.34) and site #3 (5, 1.25). It was generally decreased the relative germination ratio (r=-0.731, p<0.01), the mean germination time, the relative elongation ratio (r=-571, p<0.01, r=-0.730, p<0.01), the relative fresh weight (r=-0.743, p<0.01), development of root hairs of receptor plants by concentration of the aqueous extracts from C. didymu. But they were different from the growing regions, the kind of receptor plants and the treatment of the aqueous extracts. Especially, it was differently effected among growing regions that inhibited more radicle than shoot by the aqueous extracts concentration of C. didymus. Total phenolic compound in the aqueous extracts of C. didymus analyzed about $23.0{\pm}1.1mg/g$. Total phenolic compounds of soil in survey area was increased gradually site #1 ($0.072{\pm}0.002mg/g$), site #2 ($0.082{\pm}0.003mg/g$) and site #3 ($0.092{\pm}0.004 mg/g$). We think that the aqueous extracts of C. didymu showed allelopathic effects on other plants. Therefore, C. didymu hold the competitive dominant of plant ecosystem in Jeju Island and possibility application of natural herbicide.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.12
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• pp.1126-1133
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• 2010

A two-stage biofilter was constructed and utilized to determine the removal efficiency when treating dynamic loading of a mixture of odorous compounds including benzene, toluene, p-xylene, ammonia and hydrogen sulfide. A yeast strain, Candida tropicalis, and a sulfur oxidizing bacterial (SOB) strain, Acidithiobacillus caldus sp., were immobilized in polyurethane media and packed in the two-stage biofilter. The experiment of dynamic loading variation was composed of (1) stepwise loading variation of all the odorous compounds (total EC test), (2) stepwise loading variation of each odorous compound, and (3) intermittent loading variation with 2-day-off and 3-day-on. The total EC test showed that the maximum elimination capacity was $61\;g/m^3/hr$ for total VOCs, and 5.2 and $9.1\;g/m^3/hr$ for ammonia and hydrogen, respectively. In addition, the inhibition between VOCs was observed when the loading of each individual VOC was varied. Especially the stepwise increase in toluene loading resulted in decreases of benzene and p-xylene removal efficiencies about 30% and 25%, respectively. However, the inhibition between organic and inorganic compounds was not observed. The intermittent loading variation with 2-day-off and 3-day-on showed that greater than 95% of the overall removal efficiency was restored in two days after the loading resumed. Consequently, the two-stage biofilter packed with immobilized microorganisms showed advantages over conventional biofilters for the simultaneous treatment of the mixture of organic and inorganic odorous compounds.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.11
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• pp.1067-1074
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• 2008

In this study, the organic carbon normalized-sorption coefficients (Koc) for the binding affinity of phenanthrene (PHE) to 16 different soil humic and fulvic acids of various origins were determined by fluorescence quenching. The humic and fulvic acids used in this study were isolated from 6 different domestic soils including Mt. Hanla soil, IHSS standard soil and peat as well as Aldrich humic acid and characterized by elemental composition, ultraviolet absorption at 254 nm, composition of main structural fragments determined by CPMAS $^{13}$C NMR. The Koc values($\times$10$^4$, L/kg C) for each of HA and FA samples were in the range of 1.48$\sim$8.65 and higher in HA compared to that of FA(3.13$\sim$8.65 vs 1.48$\sim$2.48) in the experimental condition([PHE]/[HS] = 0.02$\sim$0.2(mg/L)/(mg-OC/L), pH 6). The correlation study between the structural descriptors of humic and fulvic acids and log Koc values of phenanthrene, show that the magnitude of Koc values positively correlated with the UV$_{254}$ absorptivity([ABS]$_{254}$) and two $^{13}$C NMR descriptors (C$_{Ar-H,C}$, $\sum$C$_{Ar}$/$\sum$C$_{Alk}$), while negatively correlated with the independent descriptors of the(N+O)/C atomic ratios and $^{13}$C NMR descriptors (I$_{C-O}$/I$_{C-H,C}$). These results confirmed that the binding affinity for the hydrophobic organic compound, phenanthrene are significantly influenced by the polarity and aromaticity of soil humc and fulvic acids.

• Journal of Soil and Groundwater Environment
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• v.12 no.5
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• pp.105-114
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• 2007

The most advanced oxidation processes (AOPs) are based on reactivity of strong and non-selective oxidants such as hydroxyl radical (${\cdot}OH$). Decomposition of typical DNAPL chlorinated compounds (TCE, PCE) using various advanced oxidation processes ($UV/Fe^{3+}$-chelating agent/$H_2O_2$ process, $UV/H_2O_2$ process) was approached to develop appropriate methods treating chlorinated compound (TCE, PCE) for further field application. $UV/H_2O_2$ oxidation system was most efficient for degrading TCE and PCE at neutral pH and the system could remove 99.92% of TCE after 150 min reaction time at pH 6($[H_2O_2]$ = 147 mM, UVdose = 17.4 kwh/L) and degrade 99.99% of PCE within 120 min ($[H_2O_2]$ = 29.4 mM, UVdose = 52.2 kwh/L). Whereas, $UV/Fe^{3+}$-chelating agent/$H_2O_2$ system removed TCE and PCE ca. > 90% (UVdose = 34.8 kwh/L, $[Fe^{3+}]$ = 0.1 mM, [Oxalate] = 0.6 mM, $[H_2O_2]$ = 147 mM) and 98% after 6hrs (UVdose = 17.4 kwh/L, $[Fe^{3+}]$ = 0.1 mM, [Oxalate] = 0.6 mM, $[H_2O_2]$ = 29.4 mM), respectively. We improved the reproduction system with addition of UV light to modified Fenton reaction by increasing reduction rate of $Fe^{3+}$ to $Fe^{2+}$. We expect that the system save the treatment time and improve the removal efficiencies. Moreover, we expect the activity of low molecular organic compounds such as acetate or oxalate be effective for maintaining pH condition as neutral. This oxidation system could be an economical, environmental friendly, and practical treatment process since the organic compounds and iron minerals exist in nature soil conditions.

• Journal of the Korean Wood Science and Technology
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• v.38 no.3
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• pp.242-250
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• 2010

The aim of this study was to investigate the terpenoids of Total Volatile Organic Compounds (VOCs) released during drying of Cryptomeria japonica using the thermal extractor (TE). Considering the drying process of C. japonica, temperatures of TE were set at $27^{\circ}C$, $60^{\circ}C$, $80^{\circ}C$, $100^{\circ}C$, and $120^{\circ}C$, respectively. As the result, the emission factors of VOCs and terpenoids were increased as temperature increased. The amount of terpenoids included in VOCs emission factors were 87.5%, 81.6%, 83.6%, 90.1%, and 97.3% depending on above temperatures, respectively. Especially at$100^{\circ}C$ and $120^{\circ}C$, the amount of terpenoids were measured more than 90%. ${\delta}$-cadinene was the highest yield at each temperature and 32 types of terpenoids were collected. Emitted terpenoids were classified into the sesquiterpene group which consists of 15 carbon sources. These 32 sesquiterpenes were used for determining the useful bioactivity such as antifungal activity by the agar dilution. As the result, they showed the antifungal activity against Trichophyton rubrum, Trichophyton mentagrophytes, Microsporum gypseum. The 5,000 ppm concentration of terpenoids showed a strong activity with 100% against the 3 fungi. At the 1,000 ppm concentration of terpenoids, the antifungal activities against three fungi were 95.2%, 98.7%, and 97.3%, and their activities were a little inhibited at 100 ppm concentration.

• Korean Journal of Food Science and Technology
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• v.41 no.3
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• pp.296-301
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• 2009

In order to investigate the effect of different yeasts (La Parisienne (LP), Y18-2, Y54-3, Y90-2, Y90-9 and Y272-7) from nuruks on the quality of Glutinous rice wines, physicochemical properties and volatile flavor components were evaluated. Glutinous rice wines prepared with different yeasts were analyzed for ethanol, pH, total acid, amino acid, soluble solid, coloring degree, UV absorbance, reducing sugar, organic acid, free sugar and volatile compounds. After fermentation for 17 days, the ethanol contents ranged from 13.40 to 14.50%, while the total acid levels were from 0.33 to 0.44%. The amino acid contents in six samples ranged from 0.13 to 0.18%, while soluble solid contents ranged from 12.1 to $14.7^{\circ}Bx$. The glutinous rice wine prepared with LP showed the highest level of coloring degree, soluble solid and reducing sugar among six samples. Organic acid contents of the glutinous rice wine prepared with LP had the highest levels of lactic acid and acetic acid, while the glutinous rice wine prepared with Y90-9 had the highest level of succinic acid. In all glutinous rice wines tested, the most abundant free sugars were glucose followed by maltose. Volatile flavor components in the glutinous rice wines were identified by using GC-MSD. Nineteen esters, ten alcohols, eight acids, one aldehyde and one miscellaneous compound were identified in the glutinous rice wines. Using relative peak area, it was found that other than ethyl alcohol, hexadecanoic acid ethyl ester was the major component, predominantly found in the range of 2.73-10.41%. Phenylethyl alcohol, isoamyl alcohol, ethyl oleate, ethyl linoleate and tetradecanoic acid ethyl ester were some of the major volatile components present through the fermentation, respectively. Overall, it was shown that different yeast strains from nuruks greatly affected chemical and volatile characteristics of the glutinous rice wines.

• Food Science and Preservation
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• v.19 no.2
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• pp.249-256
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• 2012

The changes in the volatile organic compounds in plum after its electron beam irradiation and storage were determined using the simultaneous distillation extraction method and gas chromatograph-mass spectrometry. There were 44, 46, 45, 47, and 38 volatile compounds in the 0-, 0.25-, 0.5-, 0.75-, and 1 kGy irradiated samples, respectively. Also, the volatile flavor components of the plum that was stored for 30 days were identified as 48, 40, 40, 39, and 40 components. The compositions of the volatile compounds of the control and irradiated samples showed a similarity after the storage. Especially, the more important volatile flavor of the plum was identified as hexanal of the C6compounds, (E)-2-hexenal and (Z)-3-hexenal. In particular, hexanal, (E)-2-hexenal, and (Z)-3-hexen-1-ol increased in all the doses, where as hexanol and (E)-2-hexen-1-ol decreased. Among the lactone compounds, ${\gamma}$-hexalactone, ${\gamma}$-octalactone, and ${\gamma}$-decalactone were identified during the storage period in the raw samples. Hexanonic acid and 2-hexenoic acid were not identified during the storage of the samples, and 2-methylprrole was detected only when the storage samples were irradiated at a dose higher than 0.5kGy. Therefore, it was shown that there was no effect on the variation of the volatile organic component suntil 1 kGy in the plum was irradiated with an electron beam.

• Microbiology and Biotechnology Letters
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• v.35 no.2
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• pp.163-172
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• 2007

This study was designed to investigate that inorganic germanium $(GeO_2)$ did not exist in germanium-fortified yeast or obtained to non-detectable value by current analytical methods and equipments. For this purpose, we achieved $GeO_2$ qualitative analysis protocol which could be the scientific basis of the study. Since reddish brown precipitate was formed from the reaction of $GeO_2$ with 1 equiv $NaBH_4$, and dark brown precipitate was also formed from the reaction of $GeO_2$ with 2 equiv $NaBH_4$, $GeO_2$ was qualitatively analyzed by observing these particular colored-precipitates. Because no color change was showed from the reaction between $NaBH_4$ and $SiO_2$, the color change could be caused by charge transfer transition on Ge-O and B binding properties. The reaction between $NaBH_4$ and germanium-fortified yeast did not show any color change and precipitate formation which meant no $GeO_2$ existed in germanium-fortified yeast. The reaction between $NaBH_4$ and supernatant specimen collected from the outside of dialysis membrane (MWCO 1,200 dalton) did not show any color change and precipitate formation. Therefore, we considered that the both germaniums in and outside of the dialysis membrane were organic germaniums. Germanium-fortified yeast which was biosynthesized organic germanium can be applied not only as a new functional material for improving health, prevention and treatment of chronic degenerative diseases including cancers, and the regulation of immune system, but also as a new materials.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.4
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• pp.257-262
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• 2013

This study investigates the effect of fermentable carbohydrate on the concentration of odorous compounds in pig slurry. Four types of pig diet were studied: control, peanut hull (crude fiber 29.87, NDF 44.02%), golden fiber (crude fiber 48.77, NDF 65.88%), and almond hull (crude fiber 44.30, NDF 64.44%). Pigs (average BW 37.0 kg) were fed diets that met the Korean Feeding Standard (2012) and their excreta samples were collected from the slurry pits. Levels of volatile organic compounds (phenols and indoles) and volatile fatty acids were analyzed by gas chromatography. Phenol level was the lowest (p<0.05) in golden fiber (33.26 ppm) group and the highest in control (97.29 ppm). The concentration of indoles in the peanut hull (1.27 ppm), almond hull (1.20 ppm), and golden fiber (1.02 ppm) groups was lower (p < 0.05) than that of control (1.79 ppm). Levels of short chain fatty acid (SCFA) were lower (p < 0.05) in golden fiber (1,319 ppm) and almond hull (1,433 ppm) groups than in control (1,893 ppm). Concentration of branched chain fatty acid (BCFA) in the golden fiber group (74 ppm) was lower (p < 0.05) than that of control (98 ppm). Taken together, the concentration levels of phenols, indoles, and VFAs decreased on addition of peanut hull, golden fiber or almond hull to the diet, suggesting that fermentable carbohydrate may contribute to reducing odorous compounds in pig slurry.

• Food Science and Preservation
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• v.16 no.6
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• pp.991-998
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• 2009

We used pears to manufacture wine, and analyzed changes in pH, acidity and ethanol and sugar content during fermentation. Pear wine with added ginger (to improve quality) did not differ from ginger-free wine in pH or acidity level. The ethanol content of pear wine was the highest (13.0%, v/v) inpear wine with 0.1% (w/v) added ginger compared to pear wine with no ginger, and sensory tests examining taste and color yielded the highest scores for pear wine with 0.2% (w/v) ginger. To assess storage stability, pear wine was treated for 30 minutes at $55^{\circ}C$, $60^{\circ}C$, $65^{\circ}C$, or $70^{\circ}C$. Unheated pear wine showed rapid changes in pH and acidity level after 30 days of storage, whereas pear wine treated for 30 minutes at $60^{\circ}C$ did not show such changes. Total organic acid levels in pear wine increased by 0.71% and 0.89% (v/v), respectively. The free sugar level in pear wine decreased from 12.05% to 3.13% (w/v). Turning to phenolic compounds, caffeic acid, catechin, and epicatechin contents in pears were 1.64, 1.40, and 0.23 mg/100mL, respectively, with diverse compositions. Caffeic acid levels in pear wine decreased sharply to 0.12 mg/100 mL upon fermentation, whereas free catechin inpear wine increased to 1.16 mg/100 mL compared with 0.28 mg/100 mL in pears. Free arbutin increased from 8.34 mg/100 mL in pears to 10.39 mg/100 mL in pear wine. The free amino acid content of pear wine was 118.5 g/100 mL, but the levels of serine, alanine, glutamic acid, and aspartic acid decreased sharply upon fermentation, with corresponding increases in tyrosine, GABA, lysine, and arginine.