• Culinary science and hospitality research
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• v.21 no.6
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• pp.103-119
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• 2015

This study was carried out to evaluate the quality of characteristics of Takju, Yakju, and spirit made from Bunkuk(flour), Phellinus linteus and Ginger kuk. The sacharogenic power of Nuruks and pH, brix, acidity, cell numbers of yeast, and alcohol content of Deotsuls were analysed; flavors, organic acids, and sensory evaluation of Takju, Yakju, and spirit were employed in the analysis of this current study. Results showed that the saccharogenic power of Phellinus linteus kuk after fermentation of Nuruks showed the highest level, and Phellinus linteus kuk and Ginger kuk showed the same level after dry Nuruks. During fermentation of Deotsuls, pH and brix decreased with increased fermentation time, while acidity increased with increased fermentation time. Cell numbers of yeast were found to be at the highest level in Phellinus linteus kuk on the first day of fermentation, and it was the same result in the final stage(p<0.05). Alcohol content increased with an increase in fermentation time, and showed no significant difference between control and test in the final stage of fermentation. In terms of analysis of flavor components, acetone and n-amyl alcohol were not detected in Takju, Yakju, and spirit. n-butanol was detected at the highest value, followed by i-amyl alcohol. Fusel oil was detected at the highest level in spirit fermented by Bunkuk. In analysis of organic acids, lactic acid showed the highest content followed by acetic acid. Very small amounts of acetic acid were detected in the spirit and other organic acids were not detected. In sensory evaluation, Takju, Yakju, and spirit made from Phellinus linteus kuk showed the highest score. As a result of this study, Phellinus linteus kuk presented the most desirable Nuruk in order to make Takju, Yakju, and spirit.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.12
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• pp.2012-2018
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• 2013

The objective of this research was to investigate the quality characteristics of the spirits by different distillation and filtrations. The contents of alcohol, total acids, and amino acids in rice mash were 15%, 0.25 g/100 mL, and 0.15 g/100 mL, respectively. The soluble content was $10^{\circ}Brix$, and pH was 4.6 in the rice mash. Lactic acid was the most prominent organic acid found in rice mash. The rice spirit distilled by a multi stage distiller showed the highest amounts of aroma compounds, such as fusel oil and esters. However, the filtration did not affect the amounts of total aroma compounds. It is suggested that a multi stage distiller may influence taste and flavor positively by enhancing the aroma and removing the impurities in rice spirits.

• Culinary science and hospitality research
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• v.21 no.3
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• pp.232-247
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• 2015

This study was carried out to evaluate the quality of characteristics of the Takju, Yakju, spirit made by various pulse crop Nuruks which were made by Whyangonkuk(whole wheat, mung beans), Naebubijeonkuk mung beans, wheat flour, millet), Daedukuk(whole wheat, soybean). pH, Brix, total acidity, cell numbers of yeast and alcohol content of brews were analysed and flavors, organic acids, sensory evaluation of Takju, Yakju, and spirit were employed to analyze for current study. Results showed that pH value of Whyangonkuk brews during fermentation decreased the lowest, and Brix value also decreased. Total acidity of Whyangonkuk at the initial and final stage of fermentation revealed the most. Alcohol contents of Naebubijeonkuk brew presented the highest at the initial stage of fermentation, but there were no significant differences among Whyangonkuk, Naebubijeonkuk and Daedukuk at the final stage of fermentation. Cell numbers of yeast were found the most in Daedukuk at the first stage of fermentation, and cell numbers started to decrease after 2 days, but there were no significant differences at the final stage(p<0.05). In terms of analysis of flavor components, acetone and n-amyl alcohol were not detected in Takju, Yakju, and spirit. n-butanol was detected the most value followed by i-amyl alcohol. Fusel oil were detected the highest level at spirit, but no differences among Takju, Yakju and spirit. In analysis of organic acids, fumaric acid and formic acid were detected in Takju and Yakju. while 7 kind of organic acids were detected. Lactic acid showed the highest level in organic acid analysis. Takju and Yakju made by Whyangonkuk showed the highest score, and Daedukuk showed the opposite result but there were no differences in spirit made by Whyangonkuk, Naebubijeonkuk, and Daedukuk. As a result of this study, Whyangonkuk presented the most desirable Nuruk.

• 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.42 no.12
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• pp.2042-2048
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• 2013

This research was carried out to compare the physicochemical characteristics of Korean traditional spirits brewed with Phellinus linteus by different Nuruks. The spirits were produced by atmospheric distillation of rice mash added with 1~5% P. linteus and fermented by traditional and improved Nuruks. Traditional Nuruk facilitated more alcohol production than improved Nuruk during the initial fermentation time. The alcohol contents of rice mash with P. linteus ranged from 15.8 to 18.9%. Predominant volatile compounds were i-amyl alcohol of fusel oils and ethyl acetate of ester compounds in P. linteus added spirits. The spirits prepared by traditional Nuruk showed higher contents of i-butanol, n-butanol, and i-amyl alcohol than those by improved Nuruk. More ethyl acetate was produced in the spirits prepared by improved Nuruk than those by traditional Nuruk. The contents of methyl alcohol were less than 50 mg/L in P. linteus added spirits.

• Food Science and Preservation
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• v.17 no.6
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• pp.807-813
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• 2010

Muscat Bailey A grapes, one of the major grape varieties in Korea, contain 18-20% (w/w) sugars, which is less than the amount required to make red wine. In the present study, fermentation of freeze-concentrated Muscat Bailey A grape juice to $24^{\circ}Brix$ was performed using several industrial wine yeasts, including Saccharomyces cerevisiae $OC_2$, S. cerevisiae Fermivin and S. cerevisiae W-3. During fermentation, changes in the levels of soluble solids, alcohols, and yeast viable counts were monitored. Wine quality parameters including organic acid, minor alcohol, sensory score, etc. were also analyzed. Alcohol contents reached maximal levels after 9 days of fermentation, and were 12.6% (v/v) when Fermivin was used and 13% (v/v) when strains $OC_2$ and W-3 were used. No major difference between strains was apparent, except that Fermivin fermentation was somewhat slower in terms of both alcohol production and sugar consumption. Similar levels of soluble solids and total phenols were measured in wines fermented by each of the three strains. The total acid level of W-3 wine was high, whereas the alcohol content of Fermivin wine was low. Although the wines were variable in terms of acetaldehyde and minor alcohol contents, the levels of these materials were much lower than the limits set by the Korean National Tax Service. Upon sensory evaluation, $OC_2$ wine obtained the highest scores in terms of color, flavor, and overall acceptance. However, the best taste score was awarded to the Fermivin wine, which had the same flavor score as $OC_2$ wine but a slightly lower overall acceptance score.

• Journal of the Korean Society of Food Culture
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• v.6 no.3
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• pp.251-255
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• 1991

The flavor and organoleptic properties of Hongju prepared by Kokja and Koji method were tested. There was no great difference of total acid in Hongju with different fermentation methods. The alcohol content of Hongju prepared by Koji method was higher than that of Kokja method and methanol content was very little as about $0.02{\sim}0.03$ mg/ml in all samples. The aldehyde content was $7.5{\sim}32$ mg% and fusel oil was higher in Hongju prepared by Koji method than that of Kokja method. As the result of sensory evaluation, new Hongju, S-N prepared by Kokja method with wheat and rice was to be best quality.

• 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.

• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 2001.12a
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• pp.122-122
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• 2001

쌀과 같은 곡류는 전분질을 당분으로 전환시켜 술을 제조하여야 하므로 미생물이 생성하는 효소가 필요한데 그 효소원이 누룩이며 누룩은 주류의 품질이나 생산량에 영향을 미치는 가장 중요한 요소라고 할 수 있다. 본 연구는 전국44개 지역의 누룩에서 순수 분리된 89종의 곰팡이 중 효소역가와 당화력이 비교적 뛰어난 10종(Aspergillus sp. SH-412 Heunghae, Aspergillus sp. SH-422 Ulsan, Rhizopis sp. SH-606 Imdeok, Aspergillus sp. SH-607 Yhesan, Aspergilus sp. SH-613 Wolseong, Rhizopus sp. SH-654 Uncheon, Aspergillus sp. SH-660 Jeonkok, Aspergillus sp. SH-667 Dongseong, Aspergillus sp. SH-669 Uncheon, Aspergillus sp. SH-696 Daecheon)과 대조균주로 Aspergillus kawachii CF1002 그리고 효모 Saccharomyces cerevisiae를 사용하셨으며 탁주제조 중 균주별 술덧의 산도, 환원당, 아미노산도와 제조된 완성주의 유기산, 유리아미노산, 유리당, 휴젤유 및 색도를 HPLC, GC Mass, 색차계로 측정한 결과 다음과 같은 결론을 얻었다. 균주별 술덧의 주정도는 모든 실험구에서 Aspergillus kawachii보다 높았으며 특히 Aspergillus sp. SH-422는 14.9%로 가장 수율이 좋았다. 환원당은 Aspergillus sp. SH-613이 0.49%로 가장 높았고 Aspergillus sp. SH-422는 0.37%로 가장 낮았으며 산도는 시간의 경과에 따라 감소했으며 술덧 발효중 아미노산도는 시간의 경과에 따라 약간 상승 후 다소 낮아지는 경향을 보였다. 각 균주별 술덧의 유기산은 tataric acid, malic acid, succinic acid, lactic acid, acetic acid가 검출되었으며 lactic acid 함량이 2.0∼3.2g/100ml로 가장 많이 검출되었다. 유기산은 Aspergillus sp. SH-669가 가장 높게 확인되었으며 Aspergillus sp. SH-607이 가장 낮게 분석되었다. 술덧의 주 아미노산은 histidine, alanine, glutamic acid, leucine, tryptophan순으로 검출되었으며 특히 alanine은 주류에 단맛을 주는 성분으로 모든 실험구에서 많은 양이 검출되었다. 각 균주별 술덧의 유리당은 glucose가 가장 많이 검출되었으며 Fusel oil은 iso-butyl alcohol과 iso-pentyl alcohol 이 가장 많이 검출되었다. 한편 균주별 술덧의 색차를 측정한 결과 L값은 63.33∼41.98, a값은 0.09∼-3.47, b값은 17.41∼4.90으로 나타났다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.10
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• pp.1579-1587
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• 2014

This study aimed to determine the quality characteristics of fermented wine using Nuruk according to the type of aging container (jar or stainless container) and aging time. Alcohol analysis was initiated at 40.4~39.3%, and alcohol contents in the jar and stainless container decreased as aging time increased. Volatile acid content slightly increased in the reduced pressure (RP) jar and stainless container and showed a different result in the atmospheric pressure (AP) container. Amount of acetic acid did not change either in the jar or stainless container as aging time increased. In the case of 2-thiobarbituric acid (TBA), RP was lower than AP after distillation, and TBA value did not change much either in the jar or stainless container. In the case of fusel alcohol by aging time, n-propanol content did not increase either in the jar or stainless container as aging time increased. Iso-butanol content was reduced in the jar but did not change in the stainless container. In the AP container, more aromatic components were measured on the 180th day of aging time than after distillation. High boiling point aromatic components increased in particular. In the stainless container, more aromatic components were generated on the 180th day of aging, but their amount was relatively lower than in the jar. In the jar aging sensory test, the sensory score at RP 50 cmHg was highest on the 180th day of aging. In the case of AP $80^{\circ}C$ liquor, sensory score on the 180th day was the most improved.