• Journal of Animal Science and Technology
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• v.48 no.1
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• pp.91-100
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• 2006

In this study, changes of ammonia, alcohol and volatile fatty acid(VFA) concentrations or pH in in vitro ruminal fluid were studied to determine the effects of alcoholic feeds on in vitro ruminal fermentation characteristics. To formulate the alcoholic feeds, alcohol was added to commercial formulated feed at the levels of 1, 3, and 5 %. Experiments were done with four treatment groups, control(commercial feed), AF-1(commercial feed+1% alcohol), AF-3(commercial feed+3% alcohol), and AF-5(commercial feed+5% alcohol). Ammonia concentrations of AF-1 and AF-5 were significantly lower than that of control for the 12h incubation(p<0.05). Ruminal alcohol concentration was increased with the addition level of alcohol increased(p<0.05). TVFA concentrations of AF-1, AF-3 and AF-5 were significantly higher than those of control at 12h(p<0.05). Significant decrease of molar percentage of acetate was observed in control from 8 to 12h incubation, but molar percentage of acetate for AF-1, AF-3 and AF-5 was constant. Molar percentage of propionate was increased in control compared with AF-1, AF-3 and AF-5 from 8 to 12h incubation(p<0.05). Molar percentages of butyrate and valerate were higher in AF-1, AF-3 and AF-5 than in control(p<0.05). Molar percentage of caproate for AF-1, AF-3 and AF-5 was 0.05, 0.58 and 0.47M% at 8h, respectively, but that was not detected for control. Present results may indicate that the alcoholic feeds show positive effects on in vitro ruminal ammonia, alcohol and VFA concentrations or pH. Furthermore, the results of this study implies that the addition level of 5% could be more effective to ruminal fermentation than other addition levels.

• The Korean Journal of Mycology
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• v.43 no.3
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• pp.149-157
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• 2015

We examined taxonomic characteristics and safety of eight Nuruk molds that are widely used for making soybean paste, soy sauce and alcoholic beverages in Korea. HK1 from Hakyeong Fermentation Co., SW101 from Suwon Fermentation Co., CF1001, CF1002, CF1003 from Chungmoo Fermaentation Co. and KACC 93210 are yellow-Nuruk molds, and SW201 from Suwon Fermentation Co. and CF1005 from Chungmoo Fermentation Co. are white-Nuruk molds. Six strains of yellow-Nuruk molds were identified as Aspergillus oryzae. HK1, SW101, CF1001 and CF1003 of yellow-Nuruk molds have middle length of stipes ($711{\sim}1,121{\mu}m$), and CF1003 (for sake) produced less conidia and more hyphae than HK1, SW101 and CF1001 (for soybean paste). CF 1002 used for soy sauce has shorter stipes ($543{\mu}m$) and is clustered into IBLB-group based on omtA gene analysis although the other yellow-Nuruk molds are clustered into ICAo group. KACC 93210 isolated from traditional Korean Meju has very short stipes (average $270{\mu}m$), and showed velvety colonies although the others showed floccose colonies. The strain has different DNA sequences of omtA gene from other strains in NCBI GenBank as well as strains used in Korea, suggesting that it is unique from other strains published. SW201 and CF1005 of white-Nuruk molds were identified as Aspergillus luchuensis or A. luchuensis mut. Kawachii that is known as safe, non-toxigenic fungus. The six strains of yellow-Nuruk molds did not produce mycotoxins including aflatoxin, cyclopiazonic acid, and sterigmatocystin. Therefore, eight strains of Nuruk molds used for making soy sauce, soybean paste and alcoholic beverages in Korea were proved to be safe in this study.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.1
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• pp.82-87
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• 2011

A fermented alcoholic beverage made from Sikhae, a Korean traditional fermented rice beverage, has been developed using a dextran producing isolate from Kimchi and Takju yeast. When both of yeast and the isolate inoculated for fermented beverage production it produced around 4% (w/v) ethanol and oligosaccharides during fermentation. Inoculation of Takju yeast and the dextran producing isolate showed a similar fermentation profile with case of yeast inoculation only, but the rate of sucrose use was slower than the case of yeast only. TLC analysis showed that oligosaccharides were produced during the fermentation of Takju yeast and the isolate from Kimchi. Therefore, it is possible to produce a functional fermented beverage by modification of dextran fermentation.

• Mycobiology
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• v.44 no.3
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• pp.155-161
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• 2016

The most economically important species used in a wide range of fermentation industries throughout Asia belong to Aspergillus section Flavi, which are morphologically and phylogenetically indistinguishable, with a few being toxigenic and therefore a major concern. They are frequently isolated from Korean fermentation starters, such as nuruk and meju. The growing popularity of traditional Korean alcoholic beverages has led to a demand for their quality enhancement, therefore requiring selection of efficient non-toxigenic strains to assist effective fermentation. This study was performed to classify the most efficient strains of Aspergillus section Flavi isolated from various types of traditional wheat nuruk, based on a polyphasic approach involving molecular and biochemical evaluation. A total of 69 strains were isolated based on colony morphology and identified as Aspergillus oryzae/flavus based on internal transcribed spacer and calmodulin gene sequencing. Interestingly, none were toxigenic based on PCR amplification of intergenic regions of the aflatoxin cluster genes norB-cypA and the absence of aflatoxin in the culture supernatants by thin-layer chromatography analysis. Saccharification capability of the isolates, assessed through ${\alpha}-amylase$ and glucoamylase activities, revealed that two isolates, TNA24 and TNA15, showed the highest levels of activity. Although the degrees of variation in ${\alpha}-amylase$ and glucoamylase activities among the isolates were higher, there were only slight differences in acid protease activity among the isolates with two, TNA28 and TNA36, showing the highest activities. Furthermore, statistical analyses showed that ${\alpha}-amylase$ activity was positively correlated with glucoamylase activity (p < 0.001), and therefore screening for either was sufficient to predict the saccharifying capacity of the Aspergillus strain.

• Applied Biological Chemistry
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• v.27 no.3
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• pp.198-203
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• 1984

Ethanol fermentation of chemically gelatinized starch and uncooked raw starch was nested with various starchy materials. Starches were gelatinized by 5.4% NaOH and neutralized by sulfuric acid. The patterns of $CO_2$ evolving and the ethanol yield for the chemically gelatinized starch resemble those obtained with thermally gelatinized starch. The alcoholic fermentation of raw starch was carried out by the simultanous saccharification-fermentation using a commercial glucoamylase and yeast. Ethanol yield from uncooked rice starch fermentation was highly comparable to that from cooked one. $CO_2$ evolving rates of the uncooked starches of corn, barley, tapioca and sweet potato were lower than those of the cooked starches. However, the final ethanol yields were similar or slightly lower, depending on the types of starch.

• Korean Journal of Food Science and Technology
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• v.45 no.2
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• pp.252-256
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• 2013

We tested the possibility of utilizing Korea domestic wheat (winter wheat variety "keumkangmil") as a source of vinegar production. After saccharification of the whole-wheat flour with wheat malt, the saccharized liquid undergoes alcoholic fermentation, followed by acetic fermentation. Acetic acid bacterium A8, which showed the highest acetic acid production (4.56%) with domestic wheat as substrate, was selected from conventional vinegars. The strain A8 was identified as Acetobacter pasteurianus A8 through phylogenetic study using 16S rDNA sequencing analysis. The optimal condition for the malt enzyme was found to be $15^{\circ}C$ for germination periods of 6 days; its amylase activity was 608.4 U. Acetic acid production from domestic wheat substrate supplemented with 5% ethyl alcohol reached 5.8% after 24 days of static fermentation at $30^{\circ}C$ with a seeding rate of 5%.

• Korean Journal of Food Science and Technology
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• v.54 no.3
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• pp.343-350
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• 2022

In this article, we report a case study on the cause of abnormal fermentation of Takju based on a microbial community analysis of wheat-based Nuruk and Takju using next-generation sequencing. The microbial community showed notable changes during alcoholic fermentation. Members of the genera Aspergillus and Staphylococcus were dominant in Nuruk, whereas Saccharomyces, Pediococcus, Bacillus, Lactobacillus, and Enterobacter were predominant during Takju fermentation. In particular, members of the Enterobacter and Bacillus genera that were present were identified as the opportunistic pathogens B. wiedmannii and E. cloacae. The relative abundance of two species increased in Mitsul-3, wherein the concentration of organic acid rapidly decreased, and in Deotsul-1, in which raw materials were added. Furthermore, the relative abundance of lactic acid bacteria (LAB) in both the Nuruk and Takju was very low. Therefore, this result showed that the abnormal proliferation of E. cloacae and B. wiedmannii in Takju was due to the absence of LAB.

• Microbiology and Biotechnology Letters
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• v.42 no.4
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• pp.367-376
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• 2014

This study's purpose was to investigate the characteristics of a traditional Korean rice wine containing lactic acid bacteria (LAB), called makgeolli. The makgeolli was brewed with the alcohol-tolerant Pediococcus acidilactici strain K3, and was analyzed for LAB cell counts, alcoholic content, turbidity, pH, total acidity, amino nitrogen, total sugars, reducing sugars, solid contents, and organic acids. The physicochemical properties of the makgeolli were mostly maintained during fermentation (9 d) and storage (15 d). We also monitored the properties of LAB-supplemented commercial makgeollies, after adding P. acidilactici K3 at a concentration of $10^7CFU/ml$ makgeolli, for one month. Most of their properties, such as alcoholic content, turbidity, pH, total acidity, amino nitrogen, total sugars, reducing sugars, solid contents, and organic acids, were preserved during storage at $10^{\circ}C$, suggesting that makgeolli supplemented with live LAB can be produced. These results suggest that alcohol-tolerant P. acidilactici K3 can be used for makgeolli brewing either as a starter or as a supplement.

• Food Science and Preservation
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• v.22 no.3
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• pp.377-384
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• 2015

This study examined the physicochemical quality characteristics of the oriental melon Makgeolli variant by addition of sucralose during its non-steamed fermentation process. The results showed a partial increase in initial sugar content in Makgeolli depending on the level of sucralose addition; and this slight increase in sugar content was exhibited in all intervals into which the sucralose was added during fermentation. The pH of Makgeolli did not exhibit significant changes according to the level of added sucralose until the fourth day of the fermentation process; and the total acidity of Makgeolli did not significantly change in accordance with the varied levels of added sucralose. Reducing sugar rapidly decreased in all intervals of the experiment during the first day of fermentation, and it was then increased slightly staring from the second day of the fermentation. Alcohol content in all experimental intervals was proportionally increased in accordance with the amount of added sucralose during the alcoholic fermentation process. The alcohol content was reached to the final alcohol contents of control (A) 11.27%, 0.001% (w/w) (B) 11.43%, 0.002% (w/w) (C) 11.80%, and 0.003% (w/w) (D) 12.23%. The levels of acetaldehyde, 1-propanol, isobutanol, and isoamyl alcohol in Makgeolli were all proportional to the level of the amount of sucralose added in the fermentation process. The organoleptic characteristics of Makgeolli was accorded with the level of the amount of sucralose. In the sensory evaluation, the experimental interval of 0.003% (w/w) (D) showed the highest scores of 3.30, 2.67, 3.17, and 3.20 in color, odor, taste and overall, respectively.

• Korean Journal of Agricultural Science
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• v.14 no.1
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• pp.156-163
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• 1987

In these experiment, the conditions of entrapping immobilization of Zygosaccharomyces rouxii that participate in the soysauce brewing are investigated. And carried out the fermentation and aging test by immobilized Zygosaccharomyces rouxii with the hydrolyzed solution prepared from soysauce koji. The results obtained were as follows: 1. Immobilizing conditions of Zygosaccharomyces rouxii. 1) When the concentration of Na-alginate solution is 2.0-2.5%, the bead formation was very good. And the concentration of Na-alginate solution not influenced on the fermentation activity of immobilized Zygosaccharomyces rouxii. 2) Effect of ratio of the precultured Zygosaccharomyces rouxii solution and Na-alginate solution on the fermentation activity of immobilized Zygosaccharomyces rouxii was not highly recognized. But if the ratio of precultured Zygosaccharomyces rouxii solution increased, the fermentation activity of immobilized Zygosaccharomyces rouxii was slightly high. 3) The fermentation activity of immobilized Zygosaccharomyces rouxii that grew over 36hrs was higher than that grew below 24hrs. 4) Increasing the ratio of immobilized Zygosaccharomyces rouxii gel to the fermentative medium, the fermentation activity of Zygosaccharomyces rouxii was higher. 2. The fermentation test by immobilized Zygosaccharomyces rouxii with the hydrolyzed solution of soysauce koji. 1) When fermented for about 96 hrs, the alcoholic fermentation almost stopped and alcohol concentration into the hydrolyzed solution of soysauce koji was 2.6%(v/v) approximately.