• The Korean Journal of Food And Nutrition
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• v.5 no.2
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• pp.69-76
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• 1992

Sogokju, an old Korean rice wine, was brewed in laboratory scale in February, 1978, and the changes in chemical component and microorganisms in wine mash were investigated during brewing. In the course of first-mash brewing, lactic acid bacteria became the most predominant microflora in 3 days of fermentation lowering the pH of mash to 4.2. But at 7 days, the most predominant microorganism was changed from lactic acid bacteria to least, pH reached 3.6, and the saccharogenic activity of mash was reduced from initial 10 to 3.6. During second-mash brewing, remarkable changes did not occurred in pH and acidity, maintaining 3.5∼3.7 of pH and 8.0∼8.8 of acidity. Ethanol fermentation was proceeded vigorously until 20 days of fermentation, but it reached stationary state with 18.5% ethanol after 40 days, leaving reducing sugar unfermented in mash. Even if saccharogenic activity continued all during fermentation, it was thought to be too weak. The final product of Sogokju filterate, fermented for 60 day, contained 18.8% ethanol, 5.0% reducing sugar,0.4:1 total acid, 0.057% volatile acid, 0.206% amino acid and 7.3% extract. In sensory test, Sogokju scored good marks with similar level to commercial Bupju or Chungju. It had pale yellow color, gentle Nuluk-flavor and acid taste just a little strong.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.5
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• pp.828-831
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• 2013

Fermentation patterns of apple Gochujang mash prepared with different addition times of red pepper powder were investigated. Red pepper powder was added into Gochujang mash before and after fermentation of the mash. In the apple Gochujang mash without red pepper powder, viable yeast cell counts of Zygosaccharomyces rouxii Y-80 increased to 6.5 log CFU/g shortly after five days of fermentation, and ethanol concentration reached its maximum value (3.8% of the total volume) after 15 days of fermentation. On the other hand, in apple Gochujang mash prepared by the initial addition of red pepper powder before fermentation, viable yeast cell counts increased to 7 log CFU/g after 20 days of fermentation, and ethanol concentration reached 1.3% after 25 days of fermentation. Yeast growth and ethanol production were stimulated in the Gochujang mash without red pepper powder. Sensory evaluation scores were similar in the apple Gochujang regardless of addition time of red pepper powder.

• Journal of the Korean Society of Food Culture
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• v.26 no.2
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• pp.178-183
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• 2011

The objective of this study was to determine the quality and sensory characteristics of ginpi wine using different levels of ginpi at each fermentation step. In the first mash with or without ginpi, lactic acid bacteria and yeast counts were maximum between days 2 and 3 of fermentation. The reducing sugar content increased after 2 days of fermentation of the first mash. Brix content increased rapidly after 1 day of fermentation, but pH decreased rapidly. After 3 days of fermentation of the second mash, 0, 30, 60, or 90 g of ginpi were added, and the yeast counts were 8.89, 8.72, 8.81, and 8.88 \log CFU/mL, respectively but then continually decreased. After 3 days of ginpi wine fermentation of the second mash, the addition of 0, 30, 60, 90 g ginpi resulted in alcohol content of 11.40, 8.90, 9.40, and 8.95%, respectively, and after 3 days of fermentation, alcohol content increased slightly. The results of a sensory evaluation showed that overall acceptability of ginpi wine was not different with different levels of added ginpi. However, the flavor of the 90 g ginpi wine had the highest acceptability.

• The Korean Journal of Food And Nutrition
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• v.19 no.3
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• pp.288-295
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• 2006

This study was conducted to examine the possibility of improvement effect in suppression of precipitation and nasty smell creation in Takju mash. First of all, gum shown to be lowest precipitation velocity was selected and this was applied to the fermentation of Takju mash for comparing with the control in terms of fermentation aspects and various qualities of Takju mash. Precipitation amount and precipitation velocity of suspension in Takju mash added with carrageenan was shown to be the lowest than that of others. Compared with the control, alcohol was highly generated in Takju mash added with carrageenan, especially between two and four days. Total acidity was shown to be highly increased until 2 days in Takju mash and thereafter to be slightly increased. Takju mash added with carrageenan was shown to be lower on the second stage than the control. Fusel oil produced from mash added with carrageenan was 0.046${\sim}$0.113${\mu}$l/ml and mash added with carrageenan generated less fusel oil than the control by 1.6${\sim}$3.2 fold. Yeast growth on the mash added with carrageenan was revealed to be helpful during fermentation periods. In general, sensory characteristics of Takju mash were shown to be more superior in mash added with carrageenan than in other samples. While nasty smell produced from a sample without gums was perceived after 2 days of Takju mash storage, nasty smell of Takju mash added with carrageenan was recognized after 6 days during storage. In conclusion, precipitation of suspension and nasty smell production in Takju mash were found to be suppressed by addition of carrageenan during Takju fermentation.

• Journal of the Korean Society of Food Culture
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• v.6 no.3
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• pp.245-249
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• 1991

This study was conducted to establish traditional manufacturing process of Hongju, a traditional spirit by traditional Kokja and Koji method based on different materials. In the fermentation process, the changes of temperature, pH, total acid, alcohol, total sugar and microflora in mash were analyzed. During the whole fermentation period, the temperature in mash made by Kokja method was reached to $30^{\circ}C$, and that of Koji method was reached $33^{\circ}C$. There was no significant difference in pH by different treatments and the initial pH in Koji method was pH 6.0 and the final pH was 4.0. The content of total acid was higher in mash processed by Kokja method than that of Koji method. Alcohol content was higher in mash processed by Koji method. The content of total sugar in all samples were reduced gradually according to progress of fermentation. Yeast populations in all samples were increased up to 6 days of fermentation and then decreased gradually. Lactic acid bacteria were increased until 3 days of fermentation and then decreased until the fermentation completed.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.555-562
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• 1997

The characteristics of mash qualities of takju prepared by using different nuruk (Korean-style bran koji) such as Mucor racemosus nuruk, Rhizopus japonicus nuruk, Aspergillus oryzae nuruk, Aspergillus kawachii nuruk and traditional nuruk were investigated during fermentation. At the begining of fermentation, ethanol content was in the range of $2.0{\sim}3.0%$. However, it increased to $8.2{\sim}12.6%$ after 16 days of fermentation. Takju made from Rhizopus japonicus nuruk showed higher ethanol content than treated otherwise. pH of takju made from Rhizopus japonicus nuruk showed higher value the others. Total acids were $0.15{\sim}0.20%$ at the begining of fermentation, and it increased to $0.086{\sim}1.57%$ after 16 days of fermentation. Total sugar were $16.64{\sim}17.62%$ at the begining of fermentation, but decreased to below 7.00% after 16 days of fermentation. Rhizopus japonicus nuruk showed the lowest level of total sugar content. Except ethanol, iso-amyl alcohol and iso-butyl alcohol were major part of minor alcohol in the mash of takju. Higher concentration of iso-amyl alcohol, iso-butyl alcohol and n-propyl alcohol were found in the mash of Rhizopus japonicus nuruk whereas the level of phenylethyl alcohol was high in the mash of traditional nuruk. Fusel oil was $0.002{\sim}0.411\;mg/mL$ during fermentation.

• Korean Journal of Food Science and Technology
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• v.19 no.5
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• pp.446-450
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• 1987

To re-evaluate the browning reactions of fermented soybean products, soy sauce mash with added glucose and/or tyrosine was fermented for 152 days in the presence or absence of oxygen. Glucose negatively affected brown pigmentation either singly or with tyrosine. Tyrosine-added soy sauce mash initially browned at the same rate as the control mash until 127th day and then the former continued to brown at the same steady rate while the control mash stopped further browning. Aerobically incubated mash browned much more than anaerobically incubated one when the browning was compared on the 152nd day of fermentation. More than half of the mash browning was found to be due to the oxygen-related browning during the limited 152 days of fermentation time. Both oxygen-related and oxygen-unrelated browning reactions were found to contribute to the browning of soy sauce mash. Oxygen-related browning, however, was found to be more important than the Maillard browning reaction.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.492-501
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• 2016

This study was conducted to investigate the physiochemical characteristics of Cheongju prepared using different types of rice (rice and glutinous rice) according to addition rate of Nuruk during low temperature fermentation. The characteristics of Cheongju prepared using three different temperatures ($10^{\circ}C$, $18^{\circ}C$, $25^{\circ}C$) were compared. After fermentation for 30-50 days, the pH of mash prepared at lower temperature was lower, as was that of mash made from rice relative to that prepared using glutinous rice. The total acidity was formed at lower temperature and generated in mashing prepared by glutinous rice. The organic acid content of mash made from rice at $18^{\circ}C$ was lowest, while that of mash prepared from glutinous rice was lowest at $10^{\circ}C$. The fermentation speed was lowest at $10^{\circ}C$; however, low temperature fermentation resulted in the highest alcohol content. The mash prepared from glutinous rice showed faster fermentation than that made from rice. In addition, the pH was lower when lower levels of Nuruk were added and higher in mash made from glutinous rice than that prepared from rice. The lower addition rate of Nuruk also showed a lower sugar content and final alcohol content. The levels of citric acid and lactic acid were higher, while those of succinic acid, acetic acid, and ethyl acetate were lower when lower levels of Nuruk were added. The mash prepared from glutinous rice showed a higher alcohol content than that made from rice.

• Food Science and Preservation
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• v.3 no.2
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• pp.179-185
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• 1996

This study was carried out for the purpose of improving the persimmon vinegar. Crushed persimmon(persimmon pulp) was used at alcohol fermentation using Saccharomyces bayanus for persimmon alcohol medium preparation. Glucose(8.39%) and fructose(7.96%) were the dominant free sugar in persimmon pulp before the at cohol fermentation. They decreased abruptly during alcohol fermentation and glucose was consumed more rapidly than fructose. Final alcohol concentration was finally reached to 8%(v/v) in 5 days for mentation of persimmon pulp. Pectinase pre-treatment of persimmon pulp resulted in tusker contents of galacturonic acid, galactose, methyl alcohol and isoamyl alcohol in main mash for alcohol fermentation than those in main mash prepared without pectinase pre-treatment. After alcohol fermentation tannin concentration was 350ppm and astringency was not perceived.

• Microbiology and Biotechnology Letters
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• v.22 no.1
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• pp.80-84
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• 1994

In order to induce the rapid alcohol fermentation through the increases of the cell density in a continuous alcohol fermentation of naked barley, the single-cultivation with S. cerevisiae IS-019(SCM, ordinary control), mixed-cultivation with Saccharomyces uvarum IS-026 having a flocculent ability and S. cerevisiae IS-019(MCM), and mash recirculation by single-cultivation of S. cerevisiae IS-019(MRM) modes were investigated. The cell mass in the mixed-cultivation mode was about 10% higher than that of ordinary control but the final alcohol yield was slightlyl decreased. When recycled the mash with the flow rate of 7 l/h from V$_{6}$ to V$_{5}$ fermentors under the ordinary control, the cell density was distributed at 140~170$\times $10$^{6}$ cell/ml depending upon the fermentorsorders, higher about 20% than that of the ordinary control. Under these conditions the alcohol productivity of the maximum and the overall was 12.16 g/l$\cdot $h with an alcohol of 7.6% at the V$_{5}$ fermentor and 1.19 g/l$\cdot $h with an alcohol of 8.94%, respectively. For higher cell mass it was more effective to apply the mash recirculation mode with the single-cultivation of S. cerevisiae IS-019 in a pilot scale multi-stage CSTR.