• Microbiology and Biotechnology Letters
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• v.24 no.4
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• pp.512-518
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• 1996

Eleven strains had been previously isolated from kimchi and identified in our laboratory. The ability of each strain in aroma production was investigated by sensory evaluation. Among them Saccharomyc s sp. YK-17, Saccharomyces sp. YK-18, Saccharomyces sp. YH-3 and Saccharomyces fermentati YK-19 produced fruity flavour. Especially, Saccharomyces fermentati YK-19 produced apple and pineapple-like flavours. Pichia media YK-11, Saccharomyces sp. YK-20 and Pichia chambardii YH-4 produced wine-like flavour. Debaryomyces sp. YK-6, Debarymyces coudertii YK-10, Saccharomyces sp. YK-12 and Pichia haplophilia YH-5 produced alcoholic flavours. Using the good flavour producing strains as starters, various groups of kimchi were fermented, and the sensory characteristics of each group such as odor, taste and total acceptability were evaluated. The acidic odor, moldy odor and taste were reduced by adding starter, while the fresh sourness odor and taste similar to fruity fiavour were increased by starter. Comparing with the control group, these odor, taste and total acceptability were increased in the starter-added groups, such as Pichia edia YK-11, Saccharomyces sp. YK-17, and Saccharomyces,fermentati YK- 19. Saccharomyces fermentati YK-19 added kimchi group was higher siginificantly (P<0.05) than the others at the total acceptability. Volatile compounds of the culture broth of Saccharomyces fermentati YK-19 were analysed by gas chromatography, and 6 species of esters and 4 species of alcohols were identified. Among them, the ester substances which broth largely responsible for the apple-like flavour in the sensory evaluation, were found to be ethyl 2-methyl butvrate, ethyl pentanoate and ethyl acetate.

• Journal of Microbiology and Biotechnology
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• v.28 no.9
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• pp.1493-1501
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• 2018

Wastewater from cider factories (losses during transfers, products discarded due to quality policies, and products returned from the market) exhibits a Chemical Oxygen Demand greater than $170,000mg\;O_2/l$, mainly due to the ethanol content and carbohydrates that are added to obtain the finished product. These effluents can represent up to 10% of the volume of cider produced, and they must be treated to meet environmental regulations. In this work, a process was developed, based on alcoholic fermentation of the available carbohydrates present in ciders. The impact of inhibitors at different pH, size and reuse of inoculums and different nutrient supplementation on the ethanol yield were evaluated. The use of a 0.5 g/l yeast inoculum and corn steep water as the nutrient source allowed for depletion of the sugars in less than 48 h, which increased the content of ethanol to more than 70 g/l.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.4
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• pp.602-609
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• 2002

Lao-chao is a traditional Chinese fermented rice product with a sweet and fruity flavor, containing high levels of glucose, a little alcohol and milk-clotting characteristics. In order to optimize commercial production of lao-chao, Rhizopus javanicus and Saccharomyces cerevisiae were selected as the mold and yeast starter, respectively. A commercial mixed starter (chiu-yao) was used as control. Fermentation of the experimental combination revealed a sharp drop in pH (to 4.5) on the fourth day, remaining constant thereafter. Content of reducing sugars gradually decreased throughout the entire fermentation period. Of the free amino acids, higher quantities of alanine, leucine, proline, glutamic acid, glutamine and $NH_3$ were noted. For sugars, glucose revealed the highest concentration, while organic acid levels, including those for oxalic, lactic, citric and pyroglutamic acid, increased throughout the fermentation period. Twenty-one compounds were identified by gas chromatography from aroma concentrates of the lao-chao culture filtrate, prepared using the headspace method. For the flavor components, higher quantities of ethanol, fusel oil and ester were determined in both culture filtrates. In regard to the evaluation of yogurt-like product, there were significant differences in alcoholic smell, texture and curd firmness.

• Food Science and Biotechnology
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• v.16 no.4
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• pp.526-530
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• 2007

The objective of this study was to establish the optimum alcohol fermenting conditions for the processing of kiwi wine and vinegar products. Six yeast strains were examined for their alcohol production from kiwi at $30^{\circ}C$ for 72 hr with continuous shaking at 100 rpm. Under these conditions, Saccharomyces kluyveri DJ97 produced the highest alcohol content of 10.2%. As the fermentation time extended to 96 hr, the alcohol content reached a maximum of 12.75%. The optimum alcohol fermenting conditions for kiwi fruit were accomplished when kiwi was added to an equal amount of water, inoculated with S. kluyveri DJ97 and fermented at $30^{\circ}C$ for 96 hr with continuous shaking. The content of soluble solids decreased as the alcohol concentration increased, whereas little change was observed in the pH and titratable acidity during the low temperature aging process. Other alcoholic compounds, such as methanol, isopropanol, n-propanol, isobutanol, and isoamylalcohol, tended to increase as fermentation progressed.

• Korean Journal of Food Science and Technology
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• v.49 no.6
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• pp.605-609
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• 2017

The effect of malic acid-degrading yeast on the quality of Gaeryangmerou (Vitis spp.) wine obtained from grapes commonly used for making wine in Korea was investigated. Alcoholic fermentation was carried out at $25^{\circ}C$, for 14 days. A malic acid-degrading yeast was used as the experimental sample and a commercial yeast, Fermivin, was used as a control. The fermentation process for the experimental yeast lasted 2-3 days longer than that of Fermivin. The pH and the volatile acid content of the wine were 3.94 and 244.20 mg/L, respectively. The total acid content was 0.86% for the experimental group and 0.94% for the control group. The contents of malic acid and succinic acid in the experimental group were significantly lower than that of the control group (245.61, 50.18 mg% for experimental group versus 302.44, 68.39 mg% for control group, respectively). In contrast, lactic acid content was slightly higher in the experimental group. As expected, the main volatile flavor compounds of Gaeryangmerou wine varied with the yeast used for fermentation and were determined to be isoamyl alcohol, ${\beta}$-phenethyl alcohol, 2-methyl-1-propanol, and diacetyl for the experimental wine.

• Korean Journal of Agricultural Science
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• v.4 no.2
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• pp.173-177
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• 1977

These experiments were conducted to investigate the formation of organic acid and ethanol during fermentation by three yeast strains. One of these was industrial strain (No.7) from Japan, and the others were wild types (No. 47, No. 239) isolated from Takju-mash and Strawbery, respectively. Conditions of fermentation were varied by differing the supply of oxygen (air), and by using different fermentation media The results obtained were as follows: 1) All the yeast strains produced higher amount of total organic acid and ethanol under the conditions which were aerobic, i.e. the flasks were opened during fermentation, than in case of using the flasks with fermentation bung. 2) Organic acid and ethanol were produced rapidly in the mash medium than in the semi-synthetic medium, i.e. total amount of organic acid and ethanol was maximized in a short time in the mash medium. 3) On the mash medium, the highest amount of organic acid was obtained by the strain No. 239, the next by No. 7 and the lowest by No. 47. Ethanol was produced on this medium with decreacing order of No. 47, No. 239, and No. 7. 4) The strain No. 239 was proved to be a powerful organic acid producer, yielding higher amount of organic acid especially under the aerobic conditions. 5) Above results suggests that the strain No. 239 could be of useful in alcoholic drink industry, due to its powerful ethanol-producing characteristic accompaning with high yielding of organic acids.

• Food Science and Preservation
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• v.8 no.3
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• pp.320-325
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• 2001

In fermentation characteristics, R2 was suitable for fast start and fermentation, while UCD530 was tool suitable far complete fermentation at 25$^{\circ}C$. T73 and AC- strains produced much more total acid compared to other strains and it was concerned with producing large amount of succinic acid and acetic acid. OC-2, UCD530, Beaujolais, and BC strains revealed low fermentation efficiency (below 62.0%), but EC1118, RC212, T73 and BM45 strains showed opposit result (above 70.0%). D254 and Wadenswil 27 seemed to have excellent cohesive ability because these two yeast strains made somewhat hard precipitation at the bottom after complete fermentation. T73 and CEG gave higher amounts of acetic acid (above 630 mg/L), while UCD530, W-3 and Beaujolais recorded low concentration (below 200 mg/L). In sulfur dioxide tolerance, preferable culturing temperature and times were 25$^{\circ}C$ and 72 hr respectively. The strains R2, BM45 and L2056 revealed high sulfur dioxide tolerance (above 30mg/L), white 71B, Wadenswil 27 and Beaujolais showed the opposite result (below 5mg/L)

• Korean Journal of Food Science and Technology
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• v.38 no.4
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• pp.543-547
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• 2006

In order to improve wine quality, the selection of yeast strain and of additives in the manufacture of Bokbunja (Rubus coreanus Miq.) wine was investigated. The chemical composition of the edible portions of Bokbunja fruits was 86.5% moisture, 0.2% crude protein, 0.9% crude fat, 6.6% crude fiber, 0.5% ash and $10^{\circ}Brix$ sugar, and was 2.99% fructose, 2.53% glucose and 0.07% sucrose in fruit extract. The predominant organic acids in the fruit were citric acid (14.57 mg/mL) and malic acid (2.24 mg/mL) with smaller amounts of shikimic, pyroglutamic and oxalic acid. During fermentation, citric and malic acid levels decreased, while formic and acetic acid were released. Saccharomyces cerevisiae KCCM 12224 (Sc-24) was more favorable for alcoholic fermentation of Bokbunja and the addition of 200 ppm of potassium metabisulphite to must was more efficient than other $SO_2$ sources with a higher overall acceptability score. Sc-24 increased alcohol production from 9.8 to 14.8% in a sugar concentration dependent manner $(18-28^{\circ}Brix)$. The color value of early stage Bokbunja must was improved by supplementing with Japanese apricot extract, but this did not influence the color value of Bokbunja wine after primary fermentation. The astringent taste of Bokbunja wine was reduced by removing the seed from the fruit. Sugar solution (50%, w/v) was used instead of sugar power to prevent the possibility of undissolved sugar due to insufficient mixing. This substitution did not influence sensory evaluation.

• Korean Journal of Food Science and Technology
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• v.23 no.1
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• pp.44-51
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• 1991

The thermal resistance of the important microorganisms in takju. Korean traditional turbid alcoholic beverage, was measured and optimun heating time and temperature to achieve the commercial pasteurization of these microorganisms were examined. Most of the vegetative bacterial cells in takju were destroyed by heating at over $60^{\circ}C$, except for the spore forming organisms, which did not actively grow in takju after pasteurization. The important microorganisms for the quality deterioration of pasteurized takju were then appeared to be yeast and molds, and their thermal resistances were measured. The thermal resistances of these microorganisms changed greatly depending upon the heating method. The D values of yeast in takju were 3.5 min at $65^{\circ}C$ and 0.46 min at $80^{\circ}C$ in cap-tube, and 7.1 sec at $65^{\circ}C$ and 2.3 sec at $80^{\circ}C$ in a continuous coil heat exchanger. Those of molds were 2.7 min at 65℃ and 0.25 min at $80^{\circ}C$ in cap-tube, and 3 sec at $65^{\circ}C$ and <1 sec at $80^{\circ}C$ in the coil heat exchanger. The acidity and pH did not change at $30^{\circ}C$ for two weeks after pasteurization by heating in the coil heat exchanger at $65^{\circ}C$ for 17 sec, but the viscosity increased slightly by the heat treatment. Significant differences in sensory quality, especially the formation of burnt smell and bitterness by heating takju for 12D of yeast at $70,\;80\;and\;85^{\circ}C$, respectively, were observed and this resulted in the significant reduction in overall likeness of pasteurized takju. However, when the heating temperature was fixed to $80^{\circ}C$, the overall likeness of pasteurized takju did not affected significantly by the heating time ranging from 8D to 12D of yeast. It was concluded that the optimum pasteurization condition of takju in a continuous heat exchanger was heating at $80^{circ}C$ for 23sec(10D of yeast).

• Journal of Dairy Science and Biotechnology
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• v.35 no.1
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• pp.1-7
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• 2017

Made using a natural mixed starter of lactic acid bacteria and yeast, Koumiss is a slightly alcoholic fermented mare's milk beverage, and a traditional drink of the nomadic populations of Central Asia. Cichorium intybus L. (chicory) is a sedative with potential cardioactive properties, and its oligosaccharides are beneficial in maintaining healthy gastrointestinal flora. Hence, in this study, we have generated a functional Koumiss containing two different concentrations of chicory. After fermentation of the Koumiss premix, the TA increased to 0.85~0.88%, and the pH decreased to ~4.3. The addition of either concentration of chicory had no significant effect on pH and TA. However, the taste, flavor, color, texture, and overall acceptability decreased in proportion to the added amount of chicory. This study has provided the first data on Koumiss supplemented with chicory. The results could be useful in developing high-quality Koumiss with functional activity using chicory, and allowing large-scale industrial production. Further studies are needed to determine if chicory root extract is beneficial for lifestyle-related diseases.