• The Korean Journal of Food And Nutrition
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• v.12 no.4
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• pp.427-432
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• 1999

Physicochemical and sensory properties of Takju which was brewed with a modified Nuruk made by inoculation and cultivation of Rhizopus japonicus T2. Aspergillus oryzae L2. and Hansenula sp. BC26 isolated from Nuruk were investigated as compared with those with current fermenting agents such as com-mercial Nuruk and rice koji of Aspergillus kawachii. The contents of total acid were 0.88% 0.47% and 0.39% in mash of commercial Nuruk rice koji and modified Nuruk respectively. The contents of alcohol were 15.5% 15.1% and 9.0% in mash of modified Nuruk rice koji and commercial Nuruk respectively. The contents of reducing sugar were 2.80% 1.24% and 0.80% in mash of commercial Nuruk modified Nuruk and rice koji respectively. The contents of amino acid were 0.55% 0.47% and 0.23% in mash of modified Nuruk commercial Nuruk and rice koji respectively. Suspended solids were sedimented much more slowly in Takju of modified Nuruk or commercial Nuruk than in that of rice koji Color was pre-ferred in the order of Takju of modified Nuruk commercial Nuruk and rice koji. Odor and taste were preferred in the order of Takju of modified Nuruk rice koji and commercial Nuruk. Therefore it seem-ed that the Takju of modified Nuruk was better than that of commercial Nuruk or rice koji in quality.

• The Korean Journal of Food And Nutrition
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• v.12 no.3
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• pp.219-225
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• 1999

In order to improve the quality of nuruk a Korean traditional fermenting agent for brewing nuruk was modified by a new method inoculating Rhizopus japonicus T2 Aspergillus oryzae L2 and hansenula sp. BC26 which had been isolated from traditional Nuruk. And the characteristics of modified Nuruk were investimgated as compared with current fermenting agents such as commercial Nuruk and rice koji of As-pergillus kawachii. The odor of modified Nuruk was savory but those of commercial Nuruk and rice koji were fetid andinodorous repectively. The extracted waters of modified Nuruk commercial Nuruk and rice koji were yellow pale yellow and colorless and showed 6.15, 6.01 and 3.30 of pH respectively. Mod-ified Nuruk had 7.6${\times}$106CFU/g of yeast but commercial uruk and rice koji had no yeast. Commercial Nuruk had 1.0${\times}$102CFU/g of lactic acid bacteria but modified Nuruk and rice koji had no lactic acid bacteria. The amylolytic and proteolytic activities of modified Nuruk were much higher than those of commercial Nuruk or rice koji. Seed mash of modified Nuruk had ester aroma but that of commercial Nuruk rather offensive odor and that of rice koji neither ester aroma or offensive odor. It seemed that if the modified Nuruk is used in seed mashing the supplement of acidulant is need to lower pH. The quality of modified Nuruk was thought to be much better than that of commercial Nuruk or rice koji.

• The Korean Journal of Food And Nutrition
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• v.12 no.3
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• pp.226-232
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• 1999

To evaluate the characteristics of modified nuruk made by inoculation and cultivation of Rhizopus jap-onicus T2, Aspergillus oryzae L2 and hansenula sp. BC26 three different Takju mashes were made with modified Nuruk commercial Nuruk and rice koji and the changes in microorganisms and major compon-ents of mashes were investigated uring brewing. The numbers of yeast kept higher in the mash of mod-ified Nuruk or rice koji. The numbers of lactic acid bacteria were high in mash of commercial Nuruk but those were not in mash of modified Nuruk or rice koji. all mashes showed stable pH in a day and the pH kept higher in mash of modified Nuruk than in that of commer-cial Nuruk or rice koji. Increase in the content of total acid was moderate in mash of modified Nuruk or rice koji but it was too much in that of commercial Nuruk. increase in the content of amino acid was much highr in mash of modified Nuruk or commercial Nuruk than in that of rice koji. Increase in the content of alcohol was more rapid in mash of modified nuruk or rice koji than in that of commercial Nur-uk. The content of reducing sugar kept highter in mash of commercial Nuruk or modified Nuruk than in that of rice koji. A small amount of modified Nuruk accomplished favorable fermentation showing nor-mal patterns in microbiological and physicochemical changes during brewing.

• Korean Journal of Microbiology
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• v.13 no.3
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• pp.116-122
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• 1975

Calcium and magnesium in polished rice, polished barley, what flour, and corn which were used for Yakju fermentation were determined by atomic absorption spectrophotometry and their quantitative changes in the filtrates of mashes were checked at 24 hours intervals dueing the whole brewing period. The results obtained were as follows. 1) Mineral contens of raw materials(mg% of each anhydrous materials). Ca : polished rice 8.21, polished barley 26.11, wheat flour 66.10, corn 86.63 2) Mineral contents of kojies made from raw materials (mg %of each anhydrous materials). Ca : rice koji 26.36, barley koji 97.61, what flour koji 87.69, corn koji 16.13, seeding koji 28.76 Mg: rice koji 29.29, barley koji 39.84, what flour koji 244.50, corn koji 102.64, seeding koji 143.79 3) Quantitative changes of minerals in the fitrates of mashes. Calcium contents in the filtrates of mashes were increased gradually after mashing in the first stage but unchanged till the mashes were ripened after mashing in the second stage. On the other hand, magnesium cotents were decreased gradually after increase in the the other hand, magnesium contens were decreased gradually after increase in the first stage but showed a tendency to increase gradually in the second stage. 4)Mineral contents of Yakjues produced, marketing Yakju, and natural water for brewing (g/ml). Ca : rice Yakju 72.38, barley Yakju 84.08, what flour Yakju 105.32, corn Yakju 71.26, marketing Yakju 71.50, natural water for brewing 51.25 Mg :rice Yakju 93.67, barley Yakju 62.39, wheat flour Yakju 273.34, corn Yakju 321,60, marketing Yakju 90.00, natrual water for brewing 20.00 5) Mineral contents of Yakju residues (mg% of each anhydrous matrials). Ca : rice Yakju residues 209.70, barley Yakju residues 62.83, what flour Yakju residues 133.92, corn Yakju residues 60.64 Mg : rice Yakju residues 15.62, barley Yakju residuet 13.22, wheat flour Yakju residues 59.10, corn Yakju residues 67.38

• The Korean Journal of Food And Nutrition
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• v.12 no.4
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• pp.421-426
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• 1999

The major flavor compounds of Takju mash which was brewed with a modified Nuruk made by inocu-lation and cultivation of Rhizopus japonicus T2, Aspergillus oryzae L2 and Hansenula sp. BC26 isolated from Nuruk, were analyzed, as compared with those with current fermenting agents such as commerical Nur-uk and rice koji of Aspergillus kawachii. The contents of isoamyl alcohol isobutyl alcohol and ethyl acet-ate which were known as aroma compounds in Takju were much higher in mash of modified Nuruk than in that of commercial Nuruk or ricd koji. The major organic acids were lactic fumalic and succinic acid in mash of modified and lactic and acetic acid in mash of commercial Nuruk and citric lactic and suc-cinic acid in mash of rice koji. The contents of total organic acids were 5,146mg/L, 1,706mg/L and 1, 388 mg/L in mash of commercial Nuruk rice koji and modified Nuruk respectively. The major free amino acids were glutamic acid alanine proline and histidine in mash of modified Nuruk and glutamic acid proline leucine and histidine in mash of commercial Nuruk and arginine proline and glutamic acid in mash of rice koji. The contents of total free amino acids were 14,090mg/L 12,202mg/L and 7,152 mg/L in mash of modified Nuruk commercial Nurcuk and rice koji respectively. Therefore it seemed that the Takju mash of modified Nuruk was better than that of commercial Nuruk or rice koji.

• Microbiology and Biotechnology Letters
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• v.18 no.5
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• pp.506-510
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• 1990

The Takju brewing of raw rice starch was carried out by the simultaneous saccharification- fermentation using Rhizopus sp. koji and yeast, and compared with the Takju mash brewed by the conventional method. Rhitopus koji was prepared with uncooked rice for Takju brewing without cooking of rice starch. Alcohol concentration of Takju mash brewed with uncooked rice was slightly higher of 1.8% than that with cooked one. Amino acid contents was almost double and fuse1 oil contents was lower in uncooked brewing. The Takju mash prepared after fermentation without cooking of rice had a characteristic odor of raw material and a good quality of taste.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.2
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• pp.101-108
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• 2016

We investigated changes in the physiochemical quality of sailfin sandfish sauces fermented with two kojis during long-term storage at room temperature. Four fish sauces, including a control, were prepared by salt-fermentation with soybean koji (S-koji) or rice koji (R-koji) after autolysis. During storage, for 12 months, the color and levels of amino acids, total volatile base nitrogen (T-VBN) and organic acids but not moisture, salt or total nitrogen levels or pH differed markedly according to fish sauce type. The total nitrogen level was highest in S-koji, but there was no difference in the rate of increase in amino acid levels among the four fish sauces during storage. The T-VBN, of autolysis and S-koji were significantly higher than those of the control and R-koji during the entire storage period (P<0.05). The initial organic acid level did not differ among the four fish sauces, whereas it was notably higher in R-koji than in the other sauces at the end of storage. Hunter L, a and b values decreased in all fish sauces with increasing storage time. In conclusion, soybean koji may enhance the levels of nitrogen compounds as well as T-VBN in fish sauce, while rice koji reduced the formation of excess T-VBN and increased organic acid levels during storage at room temperature.

• The Korean Journal of Food And Nutrition
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• v.6 no.4
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• pp.294-300
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• 1993

This study was carried out to investigate the influences of cultural conditions of koji on the production of saccharogenic amylase during rice-koji making by Aspergillus awamori var. kawachii which is now widely used as koji-mold in brewing Tikju and Yakju in Korea. The optimum cultural temperature for the production of saccharogenic amylase by this mold was 36$^{\circ}C$, and at this temperature it needed 40 hours of cultivation for maximum production of this enzyme. It was favorable for high production of both organic acid and saccharogenic amylase to shift the cultural temperature form initial 36$^{\circ}C$ to 32$^{\circ}C$ after 20~25 hours of cultivation. The production of saccharogenic amylase was low when the water content of steamed rice was below 35%, but its production was high at 40~60% of water content. When the quantity of conidial inoculation was too small, the production of saccharogenic amylase was low in initial phase, but it was retrived after 40 hours of cultivation. When koji-thickness was over 3cm, the production of saccharogenic amylase was markedly restricted. The saccharogenic amylase of this koji was stable at pH 2~7, and showed high activity at pH 2~5.

• The Korean Journal of Food And Nutrition
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• v.23 no.1
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• pp.70-75
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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 organic acid 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 acidity of each koji was tested. The temperature range suitable for the production of organic acid was $28{\sim}32^{\circ}C$, and 36~48 hours of cultivation at that temperature range seemed to produce the optimum results. The production of organic acid increased in proportion to the increase in water content of steamed rice from 25% to 60%. An increase in koji-thickness induced no adverse effects on the production of organic acid, and agitation-work during cultivation showed very beneficial effects.

• 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.