• Korean Journal of Food Science and Technology
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• v.46 no.1
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• pp.25-32
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• 2014

This study aimed to analyze the general ingredients and volatile compounds of ipguk (koji) and nuruk soju distilled under reduced pressure (RP) or atmospheric pressure (AP) conditions. After the secondary brewing process, soju made using ipguk had a final fermentation alcohol content of $18.0{\pm}0.6%$, whereas soju made using nuruk reached $14.3{\pm}1.7%$. The level of succinic acid was the highest in ipguk soju ($7,685.33{\pm}34.97$ ppm), but nuruk soju also showed a high level of succinic acid ($5,945.79{\pm}76.30$ ppm) after its final fermentation. In an analysis of fusel alcohol content, the level of n-propanol in ipguk soju (389.10-397.27 ppm) was similar under different RP (50 cm Hg and 60 cm Hg) and AP conditions ($80^{\circ}C$ and $90^{\circ}C$). Under RP and AP conditions, the isoamyl alcohol/isobutanol (A/B) ratio was similar, ranging from 1.32-1.35. In ipguk soju distilled under RP conditions of 50 cm Hg and 60 cm Hg, the amount of the toxic component, acetaldehyde, was 8.59 and 9.27 ppm, respectively. Under AP conditions, the amount of acetaldehyde in ipguk soju distilled at 80 and $90^{\circ}C$ was 9.80 and 10.63 ppm, respectively, indicating that the amount of acetaldehyde did not differ depending on the distilling method used. These results suggest that the liquor distilled from the mash produced using ipguk under RP conditions may be of a higher quality.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.10
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• pp.1689-1697
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• 2004

Aroma compounds in 6 different Byeolmijang were extracted by SDE (simultaneous steam distillation extraction) and analyzed with GC (gas chromatography) and GC/MS (mass-spectrometry). The major aroma compounds in the 6 different Byeolmijang during aging were 1-octene-3-ol, hexanal, benzeneacetaldehyde, benzaldehyde, furfural, pyrazine compounds, benzyl-alcohol, furan compounds and phenol type compounds. Generally, benzeneacetaldehyde, benzaldehyde, furfural, pyrazine compounds and phenol type compounds were increased during aging. On the other hand, 1-octene-3-ol, hexanal, benzyl-alcohol and furan compounds were decreased during aging. 2-Heptenal and 2,4-decadienal in Daemaekjang, pyrazine and phenol type compounds in Sanghwangjang and phenol type compounds including phenol, 4-methoxy-phenol and 4-ethyl-phenol in Mujang were identified as major aroma compounds, respectively. The major aroma compound in Bizijang was 2,4-decadienal and in Sodujang, the major aroma compounds were 2,3-dihydro-benzofuran and 2-methoxy-4-vinylphenol. Linaool, geraniol, 6-elemene, 6-lonone and ledene were detected in Jigeumjang possibly due to the addition of powdered red pepper.

• Applied Biological Chemistry
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• v.39 no.4
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• pp.268-273
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• 1996

Fundamental data for new type of product development from Lycii fructus was experimentally determined. The chemical composition, and Hunter value changes, optimum extraction, volatile components of extract under different extraction conditions and heat treatment were mainly studied. Results are summarized as follows. The proximate compositions of dried Lycii fructus were water 21.8%, total sugar 27.6%, reducing sugar 15.2%, crude protein 14.29%, crude fat 5.65%, crude fiber 7.48%, and ash 7.98% in percent stale, respectively. Extracted yield on the basic of solid extract was getting increased when more solvent was used for extraction. The most recommendable extraction was 1 to 10 part of sample to solvent ratio. When water was employed as extraction solvent, the highest amount of solid extract was obtained. Extract of Lycii fructus in terms of yields and color was most acceptable when raw sample was treated 8 minute roasting at $180^{\circ}C$ and 60 minute heating at $120^{\circ}C$, respectively. Major volatile components of fresh Lycii fructus were to hexadecanoic acid, methyl linoleate, benzyl alcohol, dimetane benzene by GC/MS. By the roasting of raw sample, the compounds of 2-methyl-2buthenal, 1,4-dimethyl benzene, and benzyl alcohol were reduced. Wheras, methyl thiopropanol, benzene acetaldehyde and ethyl linoleate were slightly increased.

• Applied Biological Chemistry
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• v.45 no.3
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• pp.138-144
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• 2002

In order to improve the quality of foxtail millet wine, zymological properties by isolated strains from Nuruk were investigated. Saccharomyces sp Y5-1 as brewing yeast, Aspergillus sp. M6-3, Aspergillus awamori 6970, and Aspengillus usamii mut. shirousamii 6959 (KCTC) as saccharifying molds were used, respectively. Acid content, soluble solids, color (b) and alcohol contents were increased during fermentation. Ethanol concentration of millet wine made with Nuruk by Aspergillus awamori 6970 and Aspergillus usamii mut. shirousamii 6959 were higher than the other, 10.6 and 10.1% respectively. Citric acid was only detected on $1{\sim}2$ day starting fermentation. Oxalic acid, lactic acid and acetic acid of millet wine were high in the wine made of Nuruk by Aspergillus usamii mot. shirousamii 6959, Aspergillus awamori 6970 and traditional Nuruk, respectively. During fermentation, glucose and xylose was higher than the others. Xylose was increased, but most of other sugar were decreased during fermentation. Acetone, ethyl acetate, methanol, ethanol, n-propanol, iso-buthanol and iso-amyl alcohol were detected In the wine made with Nuruk by Aspergillus awamori and Aspergillus usamii mut. shirousamii, iso-imyl alcohol and ethanol were high. On sensory evaluation, the wine made with Nuruk by Aspergillus usamii mut. shirousamii was the best on color and taste.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.5056-5062
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• 2011

This study was carried out to decrease intrinsic objectionable odor, bitter and fishy taste and change the biobeneficial components (gastrodin and p-hydroxybenzyl alcohol) of Gastrodia elate Blume. First of all, Gastrodia elata Blume. was dipped in the rice-washed water and rice-bran solution fermented with Lactobacillus brevis and Lactobacillus plantarum. The objectionable odor, bitter and fishy taste were decreased considerably with the treatments. Gastrodia elata Blume. was also dipped in organic acids (10 different varieties). The result showed that the most effective treatment to reduce objectionable odor, bitter and fishy taste of Gastrodia elata Blume. was treated with 1.0% lactic acid. Eleven different kinds of volatile components such as acetaldehyde, formic acid ethyl ester, acetic acid ethyl ester, 4-methylphenol and 3-hydroxy-2-butanone were separated from Gastrodia elata Blume when treated with or without 1.0% lactic acid. 4-Methylphenol, which is an objectionable odor in Gastrodia elata Blume, decreased with the treatment of lactic acid. While the contents of gastrodin and p-hydroxybenzyl alcohol in Gastrodia elata Blume. increased by 20% when dipped in 1.0% lactic acid solution for 24 hours and steamed at $98^{\circ}C$ for 4 hours.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.2
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• pp.196-201
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• 1993

In order to investigate some chemical components, higher alcohols, ethyl acetate and volatile compounds of Vitis vinifera red wines were analyzed by HPLC, GC and GC-MS. During the process of ripening for the content of wine and acids were much changed, particurally the content of tartaric acid was decreased largely. Content of total phenolics and phenol flavonoid in wines which manufactured with Malbec varieties as 470mg/L and 245mg/L respectively, was higher than those in Cabernet sauvignon (310mg/L, 135mg/L) and Cabernet franc (425mg/L, 125mg/L) wines, and nonflavonoid was higher in Cabernet franc wine(300mg/L) than in others. Content of acetaldehyde was higher in Malbec wine (33mg/L) than in Cabernet sauvignon (26mg/L) and Cabernet franc (28mg/L) wines. Amount of methyl alcohol, propanol and isoamyl alcohol were higher in Cabernet sauvignon wine than in others, and isobutanol was more in Malbec wine(64mg/L), ethyl acetate was more in Cabernet franc wine as 35mg/L than in Malbec(28mg/L) and in Cabernet sauvignon (23mg/L) wines. Volatile compounds were isolated about 87~91 varieties from concentrates of three red wines by GC, and thirty-five compounds including terpine-4-ol were identified by GC-MS.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.563-570
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• 1997

Volatile flavor components in the mash of takjus prepared by using different nuruks such as Mucor racemosus nuruk, Rhizopus japonicus nuruk, Aspergillus oryzae nuruk, Aspergillus kawachii nuruk and nuruk (Korean-style bran koji), were identified by using GC and GC-MS. Twenty alcohols, 26 esters, 10 acids, 10 aldehydes and 6 others were found in the mash of takju after 16 days of fermentation. Takju by Aspergillus oryzae nuruk had the most various components of volatile flavor. Fifty-four flavor components including ethanol, 2-methyl-1-propanol, 3-methyl-1-butanol, 1-hexanol, 2,3-butadienol (D,L), benzeneethanol, acetic acid ethyl ester, succinic acid diethyl ester, butanoic acid monoethyl ester, acetic acid and benzene acetic acid 4-acetyloxy-3-methyl ethyl ester were usually detected in all the treatments. The relative peak area of volatile components was as follows: alcohol $(71.28{\sim}90.23%)$, ester $(0.66{\sim}9.05%)$, acid $(0.2{\sim}0.6%)$ and aldehyde $(0.02{\sim}0.09%)$. Specially, 1-pentanol and hexanoic acid ethyl ester were high in takju made of nuruk (Korean-style bran koji). 1-Hexanol, 1-dodecanol, acetic acid and 1,2-benzene-dicarboxylic acid diprophenyl ester were high in takju made of Mucor racemosus nuruk. 4-Acetyloxy, 3-methyl benzeneacetic acid phenyl ester, 2-methyl-1-propanol, 3-methyl-1-butanol, succinic acid diethylester, butanoic acid monoethyl ester and butanoic acid were higher content in takju by Rhizopus japonicus nuruk. Acetic acid ethyl ester, pentanoic acid and 3-methyl butanoic acid were high in takju that was made of Aspergillus oryzae nuruk. 1-Butanol was high in takju by Aspergillus kawachii nuruk.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.3
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• pp.305-317
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• 2010

In this research, a total of 11 newly designated offensive odorants in Korea in 2008 and 2010 (styrene (S), toluene (T), p-xylene (p-X), methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), butyl acetate (BuAc), isobutyl alcohol (i-BuAl), propionic acid (PA), butyric acid (BA), isovaleric acid (IA), and valeric acid (VA)) were selected as target compounds and analyzed from two types of gutter system in the urban environment. Because of the environmental significance of these compounds as offensive odorants, the results are meaningful enough to explore their behavior and distribution in the urban environmental systems. In the course of this study, samples were collected three times a day from two different gutter systems representing the wet (W) and dry (D) conditions. A large fraction of volatile organic compounds (VOCs) data fell into method detection limit (MDL) range with exceptions of toluene, p-xylene, and methyl ethyl ketone. In contrast, the results of organic fatty acids were distinguished by the relative dominance of butyric acid and propionic acid over others. If the concentration data of all odorants were converted into odor intensity (OI), the results of aromatics, ketones, acetate, and alcohol groups approached zero level. However, odor intensity of organic fatty acids was noticeably higher with the value of 2.8 (on average) from both W and D system, suggesting their potent roles as odorants in gutter system.

• Microbiology and Biotechnology Letters
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• v.48 no.1
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• pp.90-97
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• 2020

Vinegar was prepared from corn produced in Gangwon province and changes to the major aroma components were investigated for acetic acid fermentation and ripening. The most prevalent volatile component in corn alcohol was determined to be 2-phenylethanol (accounting for 27% of total aroma components); the levels of 2-phenylethanol decreased to 15% after acetic acid fermentation. Principal component analysis of volatile compounds revealed that corn vinegar was distinguishable from corn alcohol. The highest content of total volatile components (50%) was acetic acid, followed by 2-phenylethanol and diethyl succinate. Ethyl phenylacetate and diethyl succinate had the highest odor activity value, and might contribute most profoundly to the aroma of corn vinegar.

• Bulletin of the Korean Chemical Society
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• v.27 no.5
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• pp.718-724
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• 2006

The heterogeneous association behaviour of various concentration binary mixtures of mono alkyl ethers of ethylene glycol with ethyl alcohol were investigated by dielectric measurement in benzene solutions over the entire concentration range at 25 ${^{\circ}C}$. The values of static dielectric constant $\epsilon_0$ of the mixtures were measured at 1 MHz using a four terminal dielectric liquid test fixture and precision LCR meter. The high frequency limiting dielectric constant $\epsilon_\infty$ values were determined by measurement of refractive index $n_D$ ($\epsilon_\infty\;=\;n_D\;^2$). The measured values of $\epsilon_0$ and $\epsilon_\infty$ were used to evaluate the values of excess dielectric constant $\epsilon^E$, effective Kirkwood correlation factor $g^{eff}$ and corrective correlation factor $g_f$ of the binary polar mixtures to obtain qualitative and quantitative information about the H-bond complex formation. The non-linear behaviour of the observed $\epsilon_0$ values of the polar molecules and their mixtures in benzene solvent confirms the variation in the associated structures with change in polar mixture constituents concentration and also by dilution in non-polar solvents. Appearance of the maximum in $\epsilon^E$ values at different concentration of the polar mixtures suggest the formation of stable adduct complex, which depends on the molecular size of the mono alkyl ethers of ethylene glycol. Further, the observed $\epsilon^E$ < 0 also confirms the heterogeneous H-bond complex formation reduces the effective number of dipoles in these polar binary mixtures. In benzene solutions these polar molecules shows the maximum reduce in effective number of dipoles at 50 percent dilutions. But ethyl alcohol rich binary polar mixtures in benzene solvent show the maximum reduce in effective number of dipoles in benzene rich solutions.