• Food Science and Preservation
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• v.7 no.2
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• pp.228-232
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• 2000

To utilize abundant potatoes effectively, it was studied on alcohol fermentation strains which were isolated and identified. Fifteen yeast strains with high alcohol fermentation ability were isolated from rotted potatoes. Among them, two isolated strains, 5-3A and 10-4B showing the highest alcohol fermentation ability were identified as Zygosaccharomyces fermentati based on the morphological and physiological characteristics. Their optimum conditions for the alcohol fermentation in 25% glucose were pH 3.0, 30$^{\circ}C$ and 150 rpm of shaking speed, respectively.

• Microbiology and Biotechnology Letters
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• v.15 no.2
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• pp.75-79
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• 1987

The conventional alcohol fermentation method requires a large amount of energy for cooking the starchy raw materials prior to saccharification. The aim of this study was to compare the possibility of large scale alcohol fermentation from cassava slices were compared in low and high temperature cooking systems. The same amount of saccharifying and liquefying enzymes were used for cooking at low and high temperature. At low temperature cooking, conversion of glucose consumed in fermented mash to alcohol was 0.468g alcohol per g glucose of which was higher yield than that obtained at high temperature.

• Korean Journal of Microbiology
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• v.20 no.2
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• pp.67-72
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• 1982

The effect of fermentation temperature on the production of high content alcohol has been investigated with high substrate concentration. The maximum specific growth rate, ${\mu}max\;was\;0.461hr^{-1}\;at\;35^{\circ}C$ which was the highest, whereas the maximum biomass concentration waas 8.7g/l at $25^{\circ}C$, at the growth rate lower than at $35^{\circ}C$. Approximately 140g/l of ethanol was produced in the temperature range of 20 to $25^{\circ}C$ with nearly complete comsumption of the substrate. Extended fermentation time has been required at lower temperatures, however, for the maximum values of biomass concentration and alcohol content, hence higher ethanol productivity, as the temperature was elevated to $40^{\circ}C$. The viability of yeasts was greatly improved by lowering the fermentation temperature down to $25^{\circ}C$ and also extended survival of the cells has been observed at lower fermentation temperatures, although the ethanol concentration of both waas higher.

• Korean Journal of Food Science and Technology
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• v.47 no.4
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• pp.431-437
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• 2015

In this study, high-acidity cider vinegar (HACV) was produced by alcoholic and acetic acid fermentation of apple concentrate without any nutrients and then the optimum alcohol concentration was determined through a qualitative study. HACV was fermented with different initial alcohol concentrations (6-9%) during the process of acetic acid fermentation. The highest content of reducing sugar, organic acids, and free amino acids was observed at 6% of initial alcohol concentration. Approximately 20 types of volatile compounds were identified by solid-phase microextraction (SPME) and GC-MS. The total volatile content was the highest at 6% of initial alcohol concentration, and the acid content was the lowest at 9% of the initial alcohol concentration. The HACV produced by a two-stage fermentation process was qualitatively better than commercial HACV presenting the highest value at 6% of initial alcohol concentration. Malic acid, aspartic acid, and hexyl acetate were selected as quality index components of HACV production by two-stage fermentation on the basis of correlation between their physicochemical properties and the sensory attributes of HACV.

• Journal of Microbiology and Biotechnology
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• v.4 no.4
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• pp.316-321
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• 1994

We investigated the possibility of industrial application and economit process of high temperature fermentation by thermotolerant alcohol producing yeasts as previously reported. From the 20% glucose media, the RA-74-2 produced 11.8% (v/v) ethanol at $32^{\circ}C$ (0.5% inoculum) and 10.6% (v/v) ethanol at $40^{\circ}C$ (3% inoculum), respectively. Also, 11.3% (v/v) ethanol was produced for 96 hours in the temperature-gradient fermentation. These results suggest that the RA-74-2 could isuccessfully be applied to save the cooling water and energy in industrial scale without re-investment or modification of established fermentation systems. When potato starch was used as the substrate for the RA-74-2, high temperature fermentation above $40^{\circ}C$ was more appropriate for industrial utilization because organic nitrogen was not necessary to economical fermentation. As the naked barley media just prior to industrial inoculation, taken from the Poongkuk alcohol industry Co., were used, 9.6% (v/v) ethanol was produced at $40^{\circ}C$ for 48 hours in jar-fermentor scale (actually, 9.5-9.8% (v/v) ethanol was produced at 30~$32^{\circ}C$ for 100 hours in industrial scale). The ethanol productivity was increased by the high glucoamylase activity as well as the high metabolic ratio at $40^{\circ}C$ Therefore, if the thermotolerant yeast RA-74-2 would be used in industrial scale, we could obtain a high productivity and saving of the cooling water and energy. Meanwhile, the RA-912 produced 6%(v/v) ethanol in 10% glucose media at $45^{\circ}C$ and showed the less ethanol-tolerance compared with industrial strains. As the produced alcohol was recovered by the vacuum evaporator at $45^{\circ}C$ in 15% glucose media, the final fermentation ratio was enhanced (76% of theoretical yields). This suggest that a hyperproductive process could be achieved by a continuous input of the substrate and continuous recovery of the product under vacuum in high cell-density culture.

• 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.

• Microbiology and Biotechnology Letters
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• v.25 no.3
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• pp.266-270
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• 1997

From persimmon fruits, about 40 yeast strains were isolated and tested for their ability of alcohol fermentation were tested. Among them, two strains, RCY14 and RCY15, showing the highest alcohol fermentibility were selected for further investigations. They were identified as Saccharomyces cerevisiae and Saccharomyces kluyveri based on their morphological, cultural and physiological properties. Their optimum condition for the alcohol fermentation in YPD-15% glucose was pH 6.0, 30$circ$C and 120 rpm of shaking speed. The alcohol yields of S. cerevisiae RCY14 and S. kluyveri RCY15 in a persimmon juice were 94.54 and 96.81%, respectively. Although the alcohol yields of both strains were not very high in YPD-15% glucose, they were much higher in a persimmon juice as compared to those of S. cerevisiae Balyon-1, S. cerevisiae 701 and S. cerevisiaein W3 which are being used in the industrial alcohol fermentation.

• Food Science and Preservation
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• v.22 no.1
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• pp.100-107
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• 2015

This study was conducted to develop a high-acidity vinegar production (over TA 10%) technology using grape juice to reduce the importation of high-acidity vinegar. The manufacturing condition's effect on the quality of high-acidity vinegar using pure grape juice without the addition of other nutrients for fermentation was investigated. Twelve percent acidity in vinegar was obtained from grape wine with 6% alcohol content. The acetic-acid yield from grape wine decreased when the wine's initial alcohol content was high, which extended the induction time. The pH value was similar in all the treatment groups. The sugar content of the 1st-stage fermentation (1st AAF) was proportional to the initial alcohol content whereas in the 2nd-stage fermentation (2nd AAF), the sugar content was highest in the 6%-alcohol treatment. The major organic acids of the high-acidity grape vinegar included tartaric acid, malic acid, and citric acid. The acid content of the high-acidity initial alcohol group was higher than that of the low-acidity initial alcohol group due to the alcohol content added by the fed-batch and acetic-acid yield difference. The ethyl alcohol content was 364~6,091 ppm (the main alcohol while the others had only traces in all the groups). In conclusion, it was possible to manufacture 12% high-acidity vinegar without the addition of an external nutrient source to grape wine containing 6% initial alcohol content. Finally, a complementary study will be required to shorten the fermentation period through the fed-batch-style addition of alcohol for the purpose of industrialization.

• Journal of the East Asian Society of Dietary Life
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• v.7 no.4
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• pp.538-544
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• 1997

To utilize abundant poor persimmon fruits effectively, It was studied on alcohol fermentation strains which were isolated and indentified from poor persimmon fruits. The strains which had exellent alcohol production ability were analysized morphogical, cultural characteristics and identified Saccharomyces cerevisiae YJK 20, Sacachromyces kluveri DJ 97. Alcohol production ability between the isolated strains and industrial alcohol yeasts was compared in the YPD medium, persimmon extract medium. Isolated strains had high alcohol production ability in both of two medium, respectively. So it was expected that the strains. YKJ 20 and DJ 97 had good alcohol fermentation ability of persimmon fruits.

• Food Science and Preservation
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• v.14 no.5
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• pp.557-563
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• 2007

This study was investigated quality characteristics of alcohol fermentation broths and by-produce produced from 4 type of brown rice varieties. The result showed that Daeanbyeo(A), Baekjinju(B) and Sulkyeong(C) produced the high alcohol content(9.5, 9.7 and 9.8%) by non-steamed alcohol fermentation period whereas the Goami(D) gave poor content(3.5%). In addition, the effect of total free sugar content were examined for non-steamed alcohol fermentation period. Among these 4 type, 244.2 mg% showed the highest contents in the Goami(D). The steamed alcohol fermentation showed higher sugar content in overall with slight difference between the various brown rice. The total dietary fiber content variation according to the alcohol fermentation methods in non-steamed and steamed periods came up with the highest content in the Sulkyeong(C) fellowed by Baekjinju(B), Daeanbyeo(A), and Goami(D). The total free amino acid content by alcohol fermentation methods timed out to show the highest content in non-steamed Goami by-product followed by Goami powder steamed Goami by-product Although, the above result revealed the lowest alcohol fermentation efficiency in non-steamed Goami, but it had the highest by-product utilizing capacity. Therefore, Goami(D) was the lowest alcohol yield in alcohol fermentation treated with non-steam among groups, but Goami by-products of the Goami had the various nutritional constitutes including starch, dietary fibers and free amino acids, which can be suggested to be used as various functional food ingredient.