• Korean Journal of Food Science and Technology
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• v.46 no.1
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• pp.25-32
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• 2014

This study aimed to analyze the general ingredients and volatile compounds of ipguk (koji) and nuruk soju distilled under reduced pressure (RP) or atmospheric pressure (AP) conditions. After the secondary brewing process, soju made using ipguk had a final fermentation alcohol content of $18.0{\pm}0.6%$, whereas soju made using nuruk reached $14.3{\pm}1.7%$. The level of succinic acid was the highest in ipguk soju ($7,685.33{\pm}34.97$ ppm), but nuruk soju also showed a high level of succinic acid ($5,945.79{\pm}76.30$ ppm) after its final fermentation. In an analysis of fusel alcohol content, the level of n-propanol in ipguk soju (389.10-397.27 ppm) was similar under different RP (50 cm Hg and 60 cm Hg) and AP conditions ($80^{\circ}C$ and $90^{\circ}C$). Under RP and AP conditions, the isoamyl alcohol/isobutanol (A/B) ratio was similar, ranging from 1.32-1.35. In ipguk soju distilled under RP conditions of 50 cm Hg and 60 cm Hg, the amount of the toxic component, acetaldehyde, was 8.59 and 9.27 ppm, respectively. Under AP conditions, the amount of acetaldehyde in ipguk soju distilled at 80 and $90^{\circ}C$ was 9.80 and 10.63 ppm, respectively, indicating that the amount of acetaldehyde did not differ depending on the distilling method used. These results suggest that the liquor distilled from the mash produced using ipguk under RP conditions may be of a higher quality.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.6
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• pp.800-806
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• 2007

This study investigated the quality characteristics of kiwi wine during low temperature aging on several alcohol fermentation strains. Alcohol content increased sharply from 2 days of fermentation, and then maintained steadily after 8 days of fermentation. In the alcohol content of kiwi wine on several alcohol fermentation strains such as Sacch. cerevisiae GRJ, Sacch. kluyveri DJ97 and Sacch. cerevisiae Wine 3 showed a high value of more than 13%, 12.7% for Zigosacch. cerevisiae JK99 and 12.3% for Sacch. cerevisiae OMK, respectively. Sugar content decreased steadily during fermentation and then showed approximately $10^{\circ}$Brix on 8 days of fermentation. Total acidity ranged $1.03{\sim}1.04%$ in total samples, increased slowly during fermentation and then maintained steadily during aging. During the fermentation, L value in Hunter's color value continued to increase, a value decreased steadily and b value showed high yellow to approximately 20.0. For aging duration, L and b values decreased while a value increased. Glucose and maltose were detected as free sugars of kiwi wine. In volatile flavor compounds, alcohols were identified differently on alcohol fermentation strains, but the others showed similar tendency. In conclusion, quality characteristics of kiwi wine on several alcohol fermentation strains showed similarly; however, Sacch. cerevisiae Wine 3 was overall the most suitable.

• Food Science and Preservation
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• v.19 no.3
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• pp.413-419
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• 2012

Fermentation of ice apple wine from freeze-concentrated Fuji apple juice to 36 $^{\circ}Brix$ was carried out using Saccharomyces cerevisiae SS89, a sugar-tolerant wine yeast strain. The characteristics of the fermentation and the properties of ice apple wine were compared with those of S. cerevisiae W-3, an industrial wine yeast that was used as a control in this study. During the fermentation, the alcohol content increased more rapidly by S. cerevisiae SS89 together with the decrease of the soluble solid content, compared to S. cerevisiae W-3. It reached 12% (v/v) after 15 days of fermentation by S. cerevisiae SS89 (12.4%, v/v) and 21 days by S. cerevisiae W-3 (12.6%, v/v). The soluble solid contents of the SS89 and W-3 wines were 24.0 and 23.6 $^{\circ}Brix$, respectively. Lactic acid was detected at the highest level, followed by malic aid, among the organic acids in both wines. No big differences in the organic acid contents were observed based on the strains. In the SS89 wine, higher levels of methanol, propanol, butanol, and isoamyl alcohol were detected, together with a lower isobutanol content, compared with the W-3 wine. The SS89 wine showed higher level of intensity as well as higher Hunter's L and b color values compared to the W-3 wine. In the sensory evaluation, similar scores in color, flavor, taste, and overall preference were obtained in the two wines. Therefore, S. cerevisiae SS89 was thought to be useful for the rapid fermentation of ice apple wine.