• Journal of Life Science
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• v.23 no.6
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• pp.796-803
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• 2013

Property changes and bacterial characterizations by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) were investigated during the fermentation of Makgeollies by 5 isolated yeast strains. Changes of pH were large between day 0 (pH 6) and day 2 (pH 3) and showed less variation after then. ANOVA analyses revealed that pHs were statistically different with fermentation times (p<0.001), while strains (p=0.60) did not. Acidities were changed from 0.19 to 1.04% and showed rather high increase from day 2, and fermentation times (p<0.001) and strains (p=0.006) represented statistical differences. All strains showed less than 0.150% at amino-type nitrogen contents except S strain showed 0.442% at day 8, and there were no statistical differences with fermentation times (p=0.4558) and strains (p=0.3513). Saccharinities of C strain were higher from day 4, and fermentation times (p<0.0001) and strains (p=0.007) showed statistical differences. Large variation of alcohol concentrations (%) were observed between day 0 (0%) and day 2 (10%) and showed less variation after day 2, and there was no statistical difference with strains. Dominant prokaryotes were Lactobacillus fermentum and Pediococcus pentosaceus, which producing acids and functional materials. Dominant eukaryote was Saccharomyces cerevisiae, which might be resulted from addition of yeasts.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.11
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• pp.1829-1836
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• 2013

This study is carried out to investigate the physicochemical characteristics, microbial population, and sensory characteristics during fermentation of Korean traditional rice wine with addition of glutinous rice. The fed-batch fermentation of rice was performed by Nuruk and yeast for 10 days at $28^{\circ}C$ in a water bath. The four fermentation batches included 0, 10, 15 and 20% of glutinous rice based on the total rice contents. The growth of total viable cells, lactic acid bacteria (LAB), and yeasts were similar among the four batches during the fermentation period. The population for total viable cells and LAB were increased for the first 3 days, and decreased slowly until 10 days. The number of yeast cells was rapidly decreased after day 6, when the alcohol content reached about 15% for all the fermentation batches. Physicochemical characteristics, such as pH, total acidity, and reducing sugars, were not different with the increase of additional glutinous rice contents. The ethanol production was higher in Korean traditional rice wine from non-glutinous rice (17.1%) than ones from glutinous rice (15.8~16.7%). For the sensory evaluations, Korean traditional rice wine with 15% glutinous rice was highly preferred due to the highest sweetness.

• Food Science and Preservation
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• v.23 no.3
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• pp.402-412
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• 2016

Generation of biogenic amines (BAs) and physiological activities of Makgeolli, Korean rice wine, were investigated during fermentation under different temperatures (20, 25, and $30^{\circ}C$) and time (3, 5, and 7 days). The pH was 3.96~4.36 during fermentation and the acidity increased proportionally with temperature and time. Alcohol and total phenolic contents peaked on day 5 at 25 by 9.0~9.8% and $3.01{\pm}0.07mg/g$, respectively. The organic acid mostly produced was lactic acid, which increased gradually with temperature and time. Formation of biogenic amines comprised of tryptamine and putrescine was observed during fermentation: 6.91, 11.70, and 15.63 mg/mL of tyramine on day 7 at 20, 25, and $30^{\circ}C$, respectively. Antioxidant activities from DPPH and FRAP assay were high in the order of $25^{\circ}C$>$20^{\circ}C$>$30^{\circ}C$ while that from ABTS assay was high regardless of temperature. Processed at 1 mg/mL and $30^{\circ}C$, the inhibitory effect on ${\alpha}$-amylase was $67.99{\pm}0.11$, $73.64{\pm}0.43$, and $75.51{\pm}0.26%$ on days 3, 5, and 7, respectively, which increased proportionally with temperature and time. Inhibitory activity on lipid accumulation in 3T3-L1 adipocytes was the highest in Makgeolli fermented on day 5 at $25^{\circ}C$. This study shows that fermentation at $25^{\circ}C$ for 5 days yields Makgeolli of the best quality with high bioactivities but no biogenic amines.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.6
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• pp.928-934
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• 2015

The objective of this study was to reduce Nuruk flavor in Korean rice-distilled liquor using different ratios of $Sumizyme^{TM}$ and Nuruk. After 9 days of fermentation at $28^{\circ}C$, alcohol contents and pH were 16.0~17.1% and 3.82~4.16, respectively. An increased ratio of $Sumizyme^{TM}$ decreased alcohol content while increased pH of the mash. In alcohol contents, there were no significant differences up to 30% substitution of Nuruk to $Sumizyme^{TM}$. A descriptive analysis was conducted with trained panelists for determining the intensity of Nuruk flavor. The intensities of Nuruk flavor in mashes and distilled liquors brewed by traditional Nuruk, cultured Nuruk, and a mixture of 30% $Sumizyme^{TM}$ and 70% cultured Nuruk were evaluated. The mash and distilled liquor prepared using a mixture of 30% $Sumizyme^{TM}$ and 70% cultured Nuruk showed significantly lower intensities of Nuruk flavor when compared with those of mashes and distilled liquors produced by the traditional and cultured Nuruk.

• Journal of the Korean Society of Food Culture
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• v.6 no.3
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• pp.251-255
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• 1991

The flavor and organoleptic properties of Hongju prepared by Kokja and Koji method were tested. There was no great difference of total acid in Hongju with different fermentation methods. The alcohol content of Hongju prepared by Koji method was higher than that of Kokja method and methanol content was very little as about $0.02{\sim}0.03$ mg/ml in all samples. The aldehyde content was $7.5{\sim}32$ mg% and fusel oil was higher in Hongju prepared by Koji method than that of Kokja method. As the result of sensory evaluation, new Hongju, S-N prepared by Kokja method with wheat and rice was to be best quality.

• Journal of Microbiology and Biotechnology
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• v.21 no.1
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• pp.43-49
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• 2011

As a rare sugar alcohol, L-arabitol can be used in food and can prevent extra fat deposits in the intestinal tract. Commercially, L-arabitol is prepared from pure L-arabinose by hydrogenation, which needs a high temperature and high pressure, leading to a high production cost for Larabitol. Therefore, this study describes a novel L-arabitol production method based on biological purification from the xylitol mother liquor, a cheap and readily available raw material that contains a high concentration of Larabitol. First, a novel Bacillus megaterium strain was screened that can utilize xylitol, sorbitol, and mannitol, yet not L-arabitol. The isolated strain was inoculated into a medium containing the xylitol mother liquor under formulated culture conditions, where a high L-arabitol yield (95%) and high purity (80%) were obtained when the medium was supplemented with 50 g/l of xylitol mother liquor. Upon further purification of the fermentation broth by ion exchange and decolorization, L-arabitol was crystallized with a purity of 98.5%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.3
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• pp.481-489
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• 1994

Volatile flavor compounds in low salt-fermented anchovy pastes by adding koji(Koji), compared with Control, were analyzed by simultaneous steam distillation -solvent extraction /gas chromatography/mass spectrometry. Volatile compounds (106) were detected inboth samples during fermentation. Among these, 79 compounds were positively identified and were composed mainly of aldehydes, esters, alcohols, ketones, nitrogen-containing compounds, aromatic hydrocarbons, and furans. Aldehydes and esters were found higher amounts that other compounds in both samples. Alkylpyrazine, such as 2, 6-dimethylpyrzine, 2-ethyl-6-methylpyrazine, trimethylpyrazie, 2-ethyl-3, 5-dimethylpyrazine and tetramethylpyrazine, and also 2-phenylethanol were identified only in Koji.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.311-314
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• 2001

In order to develop a new Korean traditional liquor using acasia, the condition of alcohol fermentation was investigated by addition of 5%, 10%, 15% nuruk and 10% acasia into mash, The maximum amounts of ethanol was produced when 10% acasia flower and 15% nuruk was added in cooked rice and fermented by S, cerevisiae at $25^{\circ}C$ for 20 days, The acceptability and physiological functionalities of acasia liquors with different concentrations(5%, 10%, 15%, 30%. 50%) of acasia flower were compared. The A -15 liquor which was brewed by addition of 15% acasia flower into mash showed the best acceptability, and its electron-donating ability and nitrite-scavenging activity were also high.

• KSBB Journal
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• v.17 no.3
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• pp.266-270
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• 2002

Alcohol fermentation conditions for the production of Chinese quince wine were investigated. Ethanol was produced maximally when 5% Saccharomyces cerevisiae was added to Chinese quince iuices and fermented at $25^{\circ}C$ for 10 days. Physiological functionalities of the Chinese quince wines were determined and compared with those of Chinese quince liquors made by seating of Chinese quince in a mixture of commercial soju and 10% sugar for 30 days and 60 days. Angiotensin-converting enzyme inhibitory activity and fibrinolytic activity of the Chinese quince wine were 36.7% and 24.0 U, respectively. Tyrosinase inhibitory activity and nitrite scavenging activity of the Chinese quince liquors were 96.7% and 52.7%, respectively and it were similar to those of the Chinese quince liquor trade from soaking of 60 days. Chinese quince wine was showed strong antibacterial activities against Staphylococcus aureus (8.5 mm of clear zone) and Klebsiella pneumonia(4.0 mm of clear zone).

• Microbiology and Biotechnology Letters
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• v.27 no.3
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• pp.236-245
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• 1999

Andong Soju is a Korean traditional distilled liquor brewed with Nuruk which is cultured with wild microorganisms. To provide useful information for scientific production and systematic quality control of traditional distilled liquor, the effects of mixed culture of the alcoholic yeasts and saccharifying molds isolated from the Nuruk, and mashes on the flavor and sensory characteristics were investigated. Distillate from mashes cocultured with Saccharomyces cerevisiae and Hansenula anomala using Mucor Nuruk was compared with distillate from mashes brewed with Andong Nuruk and with distillate from plant fermented mashes to analyze their flavor characteristics. The volatile flavor compounds in distillates were analyzed by GC and GC-MS using direct injection, solvent extraction, and purge & trap methods. Alcohols such as 3-methyl-1-butanol, 2-methyl-1-propanol, 1-propanol, and 2-phenyl ethanol; aldehydes such as acetaldehyde and 2-furancar-boxaldehyde; esters such as ethyl ester of acetic acid, hexanoic acid, octanoic acid, decanoic acid; alkanes, alkenes, ketone, sulfur, and pyrone compounds were detected. Alcohols were chief components of flavor compounds. No significant difference in overall acceptability test was shown among three experimental groups(p<0.05), but Nuruk-like aroma, Kaoliangchiew-like aroma, sweet taste, and well rounded mouthfeel showed significant differences among them(p<0.05).