• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.10a
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• pp.22-22
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• 2001

Enzymes have been used in practical applications as diverse as brewing and industrial fermentations, detergent, analytical determinations and recombinant DAN technology. As processing aids, enzymes have been used in the manufacture of food products to improve their quality, solubility and stability for centuries. About 50％ of the enzyme used as industrial processing aids are pretenses which have been used in a number of industrial applications including laundry detergents, chill proofing, meat tenderizing, fermented sauces, and the production of pharmaceuticals. (omitted)

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.8
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• pp.466-473
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• 2018

The purpose of this study is to develop a distilled soju with high quality and stable brewing technology by analyzing the changes of general components and volatile components in the production of distilled soju by the use of fermentation agent such as koji and nuruk. White rice flour was used as a main raw material. White koji, yellow koji, traditional nuruk, and improved nuruk were used as a fermentation agent respectively. Also, yellow koji, traditional nuruk, and improved nuruk were added at a certain ratio to prepare white koji. The distillate was prepared by vacuum distillation and the quality characteristics were compared and analyzed. When the fermentation agent was used alone, the alcohol content was higher in the order of white koji, improved nuruk, yellow koji, and traditional nuruk. The initial acidity was higher than that of other fermentation agents and the highest alcohol content was found to be helpful for stable brewing. The highest content of higher alcohol was found in the yellow koji mash, and ethyl acetate was the highest in the traditional nuruk. When the fermentation agents were mixed, there was no difference in the alcohol content between $1^{st}$ fermentation mash and $2^{nd}$ fermentation mash. On the other hand, the content of higher alcohol was increased with the increase of the input ratio of yellow koji, and it decreased with the increase of the ratio of traditional and improved nuruk. It is expected that it will be possible to manufacture various distilled soju with different flavor and aroma if the yellow koji and the traditional nuruk are appropriately used based on the white koji having excellent fermentation characteristics and it will be very helpful for improving the stability and quality of brewing.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.637-645
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• 2016

This study was conducted to investigate the characteristics of fermentation and quality of Cheongju prepared by mashing using rice Nuruk inoculated with Aspergillus oryzae. Mashes were prepared by fermentation for 30-50 days using different amounts of fermenting agent, brewing water, milling ratios and fermenting temperatures. Adding fermenting agent at 15% resulted in slow fermentation, but a final alcohol content of 17% (v/v), similar to other samples tested. Addition of higher amounts of Nuruk resulted in increased amounts of citric acid, tartaric acid and malic acid, but low levels of succinic acid. Incomplete fermentation occurred when the ratio of brewing water was low, but the alcohol content (17%) of all samples was similar. When the amount of brewing water was high, the organic acid was levels were high. The speed of saccharification and fermentation was low when fermentation was conducted at $10^{\circ}C$, but the final alcohol content was the highest at this temperature. However, the content of n-propanol, isobutanol, isoamyl alcohol and organic acid was low at low temperature. At this time, the content of citric acid and malic acid was low, but the content of succinic acid was high. A higher milling degree resulted in a lower content of alcohol, organic acid and higher alcohols, with 10% milling resulting in a significantly higher content than the other samples.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.340-347
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• 2019

This study investigated the brewing properties of rice beer made with yeast isolated from traditional whole wheat nuruk. The experimental method was followed by alcohol fermentation and quality analysis for six months after separating the yeast from nuruk. The yeasts isolated from traditional nuruk showed normal fermentation characteristics, like those of commercial yeast, in terms of alcohol production capability, sugar content, and pH reducing power. Especially, the yeast (KCCM 301) isolated from whole wheat nuruk showed higher contents of glycogen and trehalose than that of commercial yeast, and so KCCM 301 yeast has excellent yeast vitality. Meanwhile, the yeast (KCCM 90301) isolated from traditional Nuruk produced significantly higher alcohol and ester contents than that of commercial yeast. This has a positive effect for supplementing the taste and aroma of rice beer. In conclusion, the yeasts isolated from whole wheat nuruk showed the general alcohol fermentation pattern and aroma content of rice beer. These yeasts seem to be effective in strengthening the flavor of rice beer.

• Korean Journal of Food Science and Technology
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• v.41 no.2
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• pp.151-156
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• 2009

Samhaeju is a traditional Korean noble rice wine, in which its processing is performed at low temperatures for an extended fermentation time and with three brewing steps. In this study, Samhaeju was prepared by different brewing methods that were modified from the method in the literature. Chemical composition of samples were determined to evaluate the quality of the Samhaeju. The Samhaeju was analyzed for pH, total acids, amino nitrogen, Hunter color values, free sugars, organic acids, and volatile components. Before the addition of the second and third mashing, pH values had decreased slightly and total acids had rapidly increased. Free sugar and amino nitrogen contents were high in final product. After addition of the third mashing as the advanced step, a dilution effect was shown. Glucose (A: 0.77-7.0%, B: 0.77-3.81%) was a major free sugar, and lactic acid (A: 0-2,840mg%, B: 0-3,375mg%) was a major organic acid during the entire period of fermentation. Based on principal component analysis of electronic nose data for the components, the stages of Samhaeju fermentation were primarily separated along the first principal component (PC, proportion : 98.67%). The first PC component (PC1) was moved from negative value(-6.16) to positive value(9.00) with increasing fermentation time. The change patterns for pH and total acid during the fermentation period were similar to those of PC1 from the data obtained by electronic nose based on mass spectrometry.

• Korean Journal of Food Science and Technology
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• v.46 no.6
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• pp.694-701
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• 2014

This study aimed to investigate the aging of liquor brewed with fermented wine using ipguk (koji) in a jar (JA) and stainless steel container (SC), which are generally used in Korea, and to review the characteristics of the liquors as a function of aging time. The initial alcohol content was 39.8-40.9%, and gradually decreased in the JA and SC as the aging time increased. In the case of fusel alcohols, the n-propanol, isobutanol, and isoamyl alcohol contents did not increase with increasing aging time, in the cases of both JA and SC. The A/B (isoamyl alcohol/isobutyl alcohol) ratio was similar under reduced pressure (RP) and atmospheric pressure (AP), at 1.32-135. The A/P (isoamyl alcohol/n-propanol) and B/P (isobutyl alcohol/n-propanol) ratios were 2.17-2.22 and 1.62-1.68, respectively. During the early stages of distillation, under RP, the isoamyl alcohol content was the greatest, followed by isobutyl alcohol and ethyl palmitate. Under AP, the isoamyl alcohol content was the greatest followed by decanoic acid, ethyl palmitate, and isobutyl alcohol. The highest sensory score under RP, 60 cmHg, was $6.98{\pm}0.28$.

• The Korean Journal of Food And Nutrition
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• v.26 no.1
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• pp.78-84
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• 2013

To reproduce the brewing process of Hongkuk-ju and to identify the functional properties of it, Hongkuk-ju was brewed using different additions of Hongkuk (100%, 90%, 70%, 50%) and Nuruk (0%, 10%, 30%, 50%). The quality elements, including pH, total acidity, reducing sugar content, alcohol content and pigments (yellow, red, monacolin K and citrinin), were measured. The pH values of Hongkuk-ju showed a slight difference (pH 4.08~4.58) right after the $1^{st}$ stage mash; further, the pH on all groups (H1, H2, H3 and H4) in the terminal of the $2^{nd}$ stage mash (9 days in fermentation) were similar, ranging approximately at pH 3.70. The total acidity change did not show a difference directly the $1^{st}$ stage mash (nearby 0.2 %); however, it began to show a slight difference at the terminal of the $2^{nd}$ stage mash between the range of 0.69~0.76%. The residual reducing sugar of the content was decreased with the increased Nuruk content. The alcohol concentrations of the treatment brew with Nuruk ranging from 12.3% to 13.7% were higher than Hongkuk on its own. The yellow and red pigment contents of Hongkuk-ju ranged from 7.2~8.8 O.D. units (yellow pigment) and from 4.4~5.1 O.D. units (red pigment). The production of monacolin K and citrinin was the highest (9.48 mg/kg and 10.14 mg/kg) when the treatment solely brewed Hongkuk. The concentration of Nuruk and the preparation of the seed mash from it were critical factors compared to the treatment of rice in brewing Hongkuk-ju.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.417-421
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• 2012

The optimum conditions for manufacturing pomegranate makgeolli, cloudy Korean rice wine, treated with different levels of pomegranate (Punica granatum L.) juice concentrate were investigated. The pH, titratable acidity, amino acid content, soluble solid content, and alcohol content were measured, and the sensory properties of the makgeolli were evaluated. The pH, titratable acidity, soluble solid content and alcohol content of pomegranate makgeolli increased as the addition level of pomegranate juice concentrate increased. The amino acid content of makgeolli significantly decreased with increasing addition level of pomegranate juice concentrate. In the sensory evaluation, makgeolli with 3% pomegranate juice concentrate added during one-step-brewing had the most preferable flavor, sweetness, bitterness and overall acceptance among all samples. In conclusion, the addition of 3% pomegranate juice concentrate during one-step-brewing for makgeolli would be the best conditions for manufacturing pomegranate makgeolli.

• Journal of the Korean Society of Food Culture
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• v.9 no.4
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• pp.341-353
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• 1994

This study delves into the general characteristics of spirits brewed in the Central Region of Korea-Seoul, Kyonnggi-do, Chungchung-do-paying particular attention to their varieties and fermenting methods and also comparing similarities and differences of their features. It is found first of all that there are a wide range of variety in the kinds of liquors. Among the 21 spirits investigated, not a single one resembles any one of the remaining in terms of the raw material, and the brewing method and process. Secondly, all of them use locally produced grains and can be classifiable as belonging to the common category of yakju (clean spirit) with fragrant elements added for the purpose of enhancing health or decreasing any harmful effects after drink. Thirdly, these traditional folk wines are characterized by the addition of secondarily fermented spirits. The more secondarily fermented spirit a wine has, the more fragrant and palatable it becomes and also the less harmful. Fourthly, all the spirits of this region are fermented by using yeast kodupap (steamed rice). The brewing temperature is usually around $15{\sim}20^{\circ}C$ for $5{\sim}8$ days or $3{\sim}4$ days for the majority of the cases. Fifthly, purifying is done with the yongsoo (strainer), the sieve, traditional Korean paper, etc. As such, we can say that all the brewers endeavor to maintain Korean traditional methods of wine making.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.609-615
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• 2004

Old rice showed higher initial pasting and peak viscosity temperatures than new rice. Reducing sugar contents of rice harvested in 1998 were lowest 24hr after digestion with saccharification enzyme, but similar after 36hr, among rice samples tested. Fermentation characteristics and preference of Takju made by fermenting raw rice harvested from 1998 to 2001 far 7 days were investigated. Alcohol contents during Takju brewing rapidly increased for 5 days to 17.3-18.1%, and were 17.5-18.2% on day 7, with those of Takju brewed with rice harvested in 1998 being highest in both cases. Sensory evaluation results showed Takju fermented with rice harvested in 2000 had highest sweetness, preference, and sourness, and that fermented with rice harvested in 1999 had highest sourness, but no voluntariness was shown between each other (meaning not clear). Moisture contents and gelatinization characteristics of old and new rice were slightly different, although factors adversely affecting Takju such as flavor of old rice did not appear in sensory evaluation probably because old rice was stored in rice bran farm for long times and used after milling. Results reveal surplus old rice could be utilized for Takju brewing.