• The Korean Journal of Food And Nutrition
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• v.23 no.3
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• pp.399-404
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• 2010

This study was conducted to determine the influence of culture conditions such as temperature, time, water content, koji-thickness, and agitation on the production of protease by Rhizopus sp. ZB9, isolated from Korean Nuruk, during the preparation of rice koji, which is used in brewing the Korean rice wines, Takju and Yakju. Rice koji was made under different culture conditions, and the proteolytic activity of each koji was tested. The temperature range suitable for the production of protease was $28~32^{\circ}C$. Based on the protease and color, 60 hours of cultivation at $28^{\circ}C$ was shown to produce optimum results. The production of protease increased in proportion to the increase in water content of steamed rice from 25% to 35%. An increase in koji-thickness induced no adverse effects on the production of protease, and agitation during cultivation showed beneficial effects.

• Korean Journal of Food Science and Technology
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• v.16 no.1
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• pp.1-6
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• 1984

The three kinds of Kochujang were prepared with liquid koji equivalent to 30%, 50%, and 70% of brewing water. The qualities of the Kochujangs during aging at $25^{\circ}C$ for 4 months were compared with those of the control group which was made from solid koji. There were no significant differences in the contents of moisture, crude protein, crude fat, NaCl and ethyl alcohol between test groups. The contents of amino nitrogen, soluble nitrogen, reducing sugar and pH of each test group during Kochujang aging were high in the order of control group. 70% liquid koji group, 50% liquid koji group and 30% liquid koji group. The pH of control group was over 5.0 during aging period. The titratable acidity of Kochujang was high in the 50% liquid koji group and the 30% liquid koji group.

• Korean Journal of Food Science and Technology
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• v.16 no.1
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• pp.7-10
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• 1984

The three kinds of Kochujang were prepared with liquid koji equivalent to 30%, 50% and 70% of brewing water and the contents of free amino acids and free sugars during aging at $25^{\circ}C$ for 3 months were compared with those of the control group which was made from solid koji. All tested Kochujang were higher in glutamic acid, lysine and aspartic acid while lower in methionine, histidine and tryptophan. The content of total free amino acids was high in the order of control group, 70%, 50%, and 30% liquid koji group. Fructose and rhamnose were found in all groups, but glucose in only the control group and 70% liquid koji group. Fructose content was the highest of the free sugars and total free sugar content was higher in the control group and 70% liquid koji group than other groups.

• Mycobiology
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• v.42 no.4
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• pp.361-367
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• 2014

Makgeolli, also known as Takju, is a non-filtered traditional Korean alcoholic beverage that contains various floating matter, including yeast cells, which contributes to its high physiological functionality. In the present study, we assessed the levels of ${\beta}$-glucan and glutathione in various yeast strains isolated from traditional Korean Nuruk and selected a ${\beta}$-glucan- and glutathione-rich yeast strain to add value to Makgeolli by enhancing its physiological functionality through increased levels of these compounds. Yeast ${\beta}$-glucan levels ranged from 6.26% to 32.69% (dry basis) and were strongly species-dependent. Dried Saccharomyces cerevisiae isolated from Nuruk contained $25.53{\mu}g/mg$ glutathione, $0.70{\mu}g/mg$ oxidized glutathione, and $11.69{\mu}g/g$ and $47.85{\mu}g/g$ spermidine and L-ornithine monohydrochloride, respectively. To produce functional Makgeolli, a ${\beta}$-glucan- and glutathione-rich yeast strain was selected in a screening analysis. Makgeolli fermented with the selected yeast strain contained higher ${\beta}$-glucan and glutathione levels than commercial Makgeolli. Using the selected yeast strain to produce Makgeolli with high ${\beta}$-glucan and glutathione content may enable the production of functional Makgeolli.

• Korean journal of food and cookery science
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• v.32 no.4
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• pp.466-475
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• 2016

Purpose: This study investigated the quality characteristics and antioxidant effects of Yakju added with rose, camellia, or cockscomb flower during fermentation. Methods: The quality characteristics and antioxidant effects were estimated including pH, amino acidity, total acid, ethanol content, color value, sensory test, electric donating ability, nitrite-scavenging ability, and ferrous ion chelating effect. Results: The pH values of Yakjus added with rose, camellia, or cockscomb flower were decreased after 2 days of fermentation and then increased after 4 days of fermentation, with final pH ranging from 4.15 to 4.27. Total acid content and amino acidity were increased during fermentation. The ethanol content in Yakjus fermented with rose, camellia, or cockscomb flower was rapidly increased after 2 days of fermentation, reaching the maximum content of 19.1% after 8 days of fermentation. In color evaluation, the L values of Yakjus added with rose, camellia, or cockscomb flower did not changes during fermentation, whereas values of a and b were increased. Total phenolic compound contents in Yakjus added with rose, camellia, or cockscomb flower were 0.67, 0.59, and 0.52 mg/mL, respectively. Total flavonoid contents in Yakjus added with rose, camellia, or cockscomb flower were 0.20, 0.09, and 0.26 mg/mL, respectively. In sensory test, the overall acceptability of Yakjus added with cockscomb flower was higher than that of Yakju added with rose or camellia flower. However, the difference was not statistically significant (p<0.05). Electron donating ability and nitrite-scavenging abilities were the highest in Yakjus added with rose flower, whereas ferrous ion chelating effect was the highest in Yakjus added with cockscomb flower. Conclusion: These results indicated that Yakjus added with rose, camellia, or cockscomb flower might have valuable functional properties due to their antioxidant effects.

• Journal of Applied Biological Chemistry
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• v.63 no.3
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• pp.229-234
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• 2020

Beer production with rice or other malt substitutes suffers from a lack of suitable enzymes for saccharification. For this reason, rice nuruk (fermentation starter) was tested as a starch replacement for malt in the saccharification process of beer production. The results of this study show that the enzyme activities of rice nuruk made with brewing fungi were higher than those of malt. Saccharification and glucoamylase activities were high in Aspergillus awamori KCCM 30790 and α-amylase activity was high in Aspergillus oryzae CF1003. Overall, malt beer had significantly higher alcohol, pH, total acid, volatile acids, amino acids, free amino nitrogen, bitterness unit and ΔE than rice nuruk beer. Where as Aspergillus awamori KCCM 30790 beer had significantly higher soluble solids, reducing sugar than malt beer. According to a sensory evaluation, malt beer was better color, flavor and Aspergillus oryzae CF1003 beer was better taste, texture, overall acceptability than other beer. Therefore Aspergillus awamori KCCM 30790 beer was suitable considering enzyme activities (saccharification, glucoalmylase) and physicochemical characteristics (soluble solids, reducing sugar). And then Aspergillus oryzae CF1003 beer was suitable considering sensory evaluation (taste, texture, overall acceptability). Therefore rice nuruk like Aspergillus awamori KCCM 30790 and Aspergillus oryzae CF1003 were suitable as a substitute material that can replace for malt in beer proceccing.

• Korean Journal of Food Science and Technology
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• v.36 no.5
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• pp.744-748
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• 2004

Effects of Monascus anka and Saccharomyces cerevisiae on wine brewing were investigated. Alcohol dehydrogenase activity in cell-free extracts of M. anka was 56.89% as compared to 100% of S. cerevisiae. Although initial fermentation was low, M. anka exhibited very similar fermentation pattern and ethanol production to those of S. cerevisiae. Acidity and reducing sugar content of red wine produced by M. anka were higher than those of S. cerevisiae-produced one. During fermentation, color value increased, whereas turbidity decreased in both red wine. M. anka-produced wine showed higher color value than S. cerevisiae-produced one. During fermentation, phenolic compounds known as antioxidants of red wine decreased. Total phenolic content (1608.01 mg/L) of M. anka-produced red wine was significantly higher than that (1337.60 mg/L) of S. cerevisiae-produced one (p<0.05). These results suggest quality of red wine could be improved using M. anka.

• Journal of the East Asian Society of Dietary Life
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• v.26 no.2
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• pp.125-140
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• 2016

We analyzed the cultural characteristics of isolated brewing fungi for developing fermentation starters. In a previous study, we collected 87 domestic nuruk, from which 481 fungi strains were isolated and 11 were selected showing improved productivity. After culturing these 11 fungi strains in several types of media, temperatures, carbon and nitrogen sources, Rhizopus sp. grew well in MEA, ME20S, PDA medium while Aspergillus sp. grew well in ME20S and YES. Both Rhizopus sp. and Aspergillus sp. survived well at optimal growth temperatures of 30 and $37^{\circ}C$. Rhizopus sp. utilized lactose, glucose and peptone sources while Aspergillus sp. utilized glucose, mannose, fructose and yeast extract sources. ${\alpha}-Amylase$ activity was excellent in L. ramosa CN044, R. oryzae 82-7(MEB), R. oryzae CN174 and A. oryzae 58-11(WEB) culture extracts. This study suggests that R. delemar 26-4, 58-8 and A. oryzae 78-5, 37-7 might be appropriate fungi strains for fermentation starters based on development of large fungi bodies and their good enzyme activities.

• Journal of the East Asian Society of Dietary Life
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• v.26 no.5
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• pp.445-449
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• 2016

In this study, Red pearl (4x) and MBA (2x) were crossed Gangwon-do Agricultural Research and Extension Services in 2000 to compare the brewing characteristics of Cheonghyang, a seedless kind of grape registered in 2009, by maturity. Fruit characteristics of Cheonghyang were examined after the first racking and 300 days after fermentation during aging in manufacturing wine based on maturity categories of being immature, mature, and overmature after harvest between August 25 and 27, 2014. The soluble solid matter content did not differ between the first racking following manufacturing wine and during ripening, and the alcohol content following the first racking was 12.9% for immature ones, 13.0% for mature ones, and 12.7% for overmature ones., The alcohol content decreased by appropriately 1.3% to 1.8% during ripening. The total acidity content was 0.9% for immature ones, 0.8% for mature ones, and 0.5% for overmature ones following the first racking and showed insignificant variations during ripening of 0.8%, 0.7%, and 0.5%, respectively, with wine made from mature ones showing proper acidity. The volatile acid content following the first racking during ripening, showing insignificant variation by maturity; however, it decreased after ripening. The sensory evaluation detected differences in acidity of wine between mature and overmature grapes. There was no difference in sour taste between immature and mature grapes; however, overmature ones had low levels of sour taste. Our results showed that mature wine had the best overall preference.

• Journal of the East Asian Society of Dietary Life
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• v.27 no.3
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• pp.348-363
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• 2017

We analyzed the mixed culture characteristics of isolated brewing fungi obtained from Korean traditional nuruk for their development as fermentation starters. In a previous study, we selected appropriate fungi strains based on their large fungi bodies and strong enzyme activities. These fungi strains were mixed cultured under various combination of ratios, pHs and temperatures. As a result, total acidities of R. delemar mixed culture media were higher than those of A. oryzae cultured at $20^{\circ}C$ and $37^{\circ}C$. The pHs of A. luchuensis 34-1 and A. oryzae 37-7 as well as R. delemar 58-8 and A. oryzae 37-7 mixed culture media gradually increased with the culture period. On the contrary, total acidities of the mixed culture media gradually decreased. ${\alpha}-Amylase$ activities of R. delemar 26-4 and R. oryzae 82-7 mixed culture media were strong at $20^{\circ}C$ and pH 4, glucoamylase activities of R. delemar 58-8 and A. oryzae 37-7 were strong at $37^{\circ}C$, pH 3 and 1:2 ratio, and acidic protease activities of R. delemar 26-4 and A. oryzae 78-5 were strong at $20^{\circ}C$, pH 4 and 1:4 ratio. This study provides the optimal mixed culture conditions for fermentation starters based on changes in pH and total acidity, favorable enzyme activities, and fungi varieties.