• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.1
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• pp.212-217
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• 1999

The effects of nuruk and wheat bran on cholesterol level in serum and activities of free radical metabolizing enzymes were investigated in rats. The rats were fed a diet containing nuruk or wheat bran for one month. Body weight and food intake were measured. Animals were sacrificed after one month. The increased food efficiency ratio throughout whole growth period was observed in the rats fed with either nuruk containing Aspergillus terreus or wheat bran compared with control group on normal diet. In the rats fed with nuruk, hepatic GSH content, glutathione S transferase activity, hepatic cytochrome P 450 content, and aniline hydroxylase activities were generally increased. In the rats fed with nuruk containing other fungi except Aspergillus terreus, xanthine oxidase activity was decreased. The decreased cholesterol level in serum was observed in rats fed with nuruk prepared from Aspergillus terreus and wheat bran. LDL cholesterol level was decreased in rats fed with nuruk prepared with other fungi such as Penicillium sp. and Rhizopus sp. But HDL cholesterol level was increased in all groups fed with nuruk from any fungi and wheat bran. These results suggested that nuruk or wheat bran supplemented diet might exert their effect by decreasing cholesterol level in serum and amount of oxygen free radical level.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.6
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• pp.1041-1048
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• 2015

This study was performed to produce quality vinegar using different types of nuruk, which is the most effective in making traditional brown rice vinegar. The vinegar was produced with 20% vinegar starter, and pears were added to reduce the nuruk aroma. Three different types of Nuruk that were prepared were rice, wheat, and a rice+wheat (1:1) combination. The total acidities of brown rice pear vinegar made from rice-nuruk, wheat-nunuk, and rice+wheat-nuruk were 8.1%, 7.5%, and 6.4%, respectively. Free sugars, including glucose, galactose, and fructose, were highly detected from all three vinegar samples. Acetic acid and lactic acid were the major organic acids in all three vinegar samples. For free amino acids, alanine, glutamic acid, and arginine were mainly detected in all three vinegar samples. Total phenolic compounds were higher in brown rice pear vinegar made of rice-nuruk than in that made of wheat-nuruk, whereas total flavonoids showed the opposite pattern. DPPH-radical scavenging activity was higher in brown rice pear vinegar made of wheat-nuruk than in that made of rice-nuruk.

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.296-302
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• 2002

Quality characteristics of mash of takju prepared by wheat flour nuruks (conventional and improved style) were investigated during fermentation. Those were cultured with wild microorganism on whole and crushed wheat (wheat nuruk), wheat flour and mixture of rice and wheat flour, and nuruk cultured with Aspergillus oryzae on wheat flour. Ethanol content reached maximum of 10.6-17.4% after 14 days of fermentation. And the ethanol contents of takju were high in order of wheat nuruk, wheat flour nuruk, Aspergillus oryzae nuruk and mixture of wheat flour and rice nuruk. No difference of pH was among the treatments while the wheat flour nuruk cultured with wild microorganisms contained higher amounts of acids than the others. The amount of total sugars ranged from 16.22-17.74% on the starting day of fermentation, and decreased to 4.28-6.10% after 14 days. The amount of total sugars in mashes brewed with wheat flour nuruk cultured with Aspergillus oryzae was measured to be highest at the beginning stage of fermentation. Afterwards no difference was found among the types of nuruks. Glucose was in the range of 2,735-7,842 mg% at initial period of fermentation, afterwards it was rapidly decreased. The total amounts of free sugar for control and the wheat flour nuruk was higher than other treatments. The total amounts of organic acids were the highest in wheat nuruk to 690-2,241 mg% and the contents of lactic acid and succinic acid were high in mixed rice nuruk to 183-1,293 mg%. The contents of lactic acid and succinic acid were higher than those of the other kinds of organic acids in takju.

• Journal of the East Asian Society of Dietary Life
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• v.27 no.2
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• pp.159-167
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• 2017

In this study, quality characteristics of yakju fermented with byeo-nuruk prepared using rice, wheat, and water were investigated. Five different mixture ratios were considered for byeo-nuruk preparation. A comparative analysis of commercial yakju and byeo-nuruk yakju was also performed. The results showed no significant differences in pH, total acidity, and total soluble solids of byeo-nuruk yakju immediately following fermentation. The byeo-nuruk yakju alcohol content increased with increasing wheat proportion. Lactic and succinic acid were the major organic acids of byeo-nuruk yakju, and the major volatile components were isoamyl alcohol and linalool. Yakju prepared using material D had the highest volatile component content and high preference evaluation scores for taste and overall acceptability. Compared to commercial yakju, byeo-nuruk yakju had less total acidity, soluble solids, and volatile acids, whereas its pH level and amino acid content were higher. No significant differences were observed between commercial yakju and byeo-nuruk yakju in terms of sensory evaluation.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.6
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• pp.897-904
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• 2011

For set up the processing method of Byeo-Nuruk, we investigated the quality characteristics of Byeo-Nuruk according to the mixture ratio of rice and wheat, as well as the addition rate of moisture. After 12 hours of incubation, the temperature of Nuruk increased dramatically and reached a maxium temperature at 36 hours. After 36 hours, the temperature decreased gradually and was maintained at about $31{\sim}38^{\circ}C$. The ranges of pH and titratable acidity of Byeo-Nuruk were 4.85 to 7.42 and 1.0 to 2.3, respectively. A higher content of wheat ratio in Byeo-Nuruk, was associated with higher enzyme activities of ${\alpha}$-amylase, glucoamylase, and acidic-protease. Further, at a 70% wheat ratio, a 25% addition rate of moisture showed the highest enzyme activity. In the mixture ratio between rice and wheat, the 50:50 and 30:70 treatments contained the highest levels of microorganisms.

• Korean Journal of Microbiology
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• v.48 no.2
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• pp.147-155
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• 2012

To improve of the quality of Korea traditional wheat-rice wine (makgeolli) production, we used a rice fermentation starter (rice nuruk) made by inoculation of Rhizopus oryzae CCS01 which was isolated and selected from commercial nuruk. Amylase activity of a rice nuruk was 1.8-2.4 times higher than those of commercial nuruks. The best acceptability of wheat-rice wine in a sensory test was observed at 4 : 6 ratio of wheat-rice mash at experimental condition. During the fermentation period, pH of wheat-rice makgeolli made with a rice nuruk was higher compared to those made with commercial nuruks such as Sanseong, Jinju, and Songhak. Acidity of makgeolli mash was lower in case of using a rice nuruk and birx and alcohol production were higher compared to those of makgeolli mash using commercial nuruks. Highest alcohol production was observed at makgeolli mash using a rice nuruk and 12% of alcohol was produced at fermentation end. These results suggest that production of a new type of wheat-rice makgeolli using a rice nuruk was possible.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.5
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• pp.767-774
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• 1997

For the standardization and quality improvement of traditional Korean Nuruk, 120 strains of fungi were isolated from Nuruks and 18 strains of them were selected as strains analysing the amylase and flavor. The genera of these fungi were identified as Aspergillus sp. (14 strains), Penicillium sp. (3 strains) and Rhizopus sp. (1 strains) by the conventional slide culture. Most of these fungi showed a better productivity of the saccharogenic and dextrinogenic enzymes in raw wheat bran culture than in cooked wheat bran culture. The ability of acid and flavor production was good in the raw wheat bran culture, and aflatoxins were not produced under the same culture. Penicillium sp. and Rhizopus sp. had high cell growth and amylast activity. Mixed culture of Aspergillus sp. No.3-6 and Penicillium sp. No.7-7 revealed a high liquefying and saccharifying activity as well as high flavors production. These results indicated that these fungi was proper strains for making Nuruk of good quality.

• The Korean Journal of Food And Nutrition
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• v.25 no.2
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• pp.253-258
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• 2012

This study was conducted to investigate the effects of different active gluten and rice Nuruk(Asp. oryzae, Asp. kawachii rice Nuruk) levels on the quality properties of steamed rice breads. Enzyme(amylase and acidic protease) activity of Asp. oryzae rice Nuruk is higher than Asp. kawachii rice Nuruk. Among the loaf volume of active gluten that were tested (10, 13, 15 and 17%) an active gluten loaf volume of 15% produced the best steamed rice bread. As a result of the loaf volume test steamed rice bread with rice Nuruk was decreased than steamed wheat bread. Regarding color, all treatments produced significant differences. The L value was decreased in steamed rice bread more than in steamed wheat bread, and a and b values were increased, respectively. Hardness, gumminess and chewiness of SRB-2, 3, 4 were lower than SWB-1 but springiness were higher. According to the sensory evaluation of steamed rice bread, color, flavor, and uniformity of pores were the highest in the steamed wheat bread, and the chewiness and texture were good in the steamed rice bread containing added active gluten and rice Nuruk. In this study, addition of rice Nuruk in steamed rice bread did not increase loaf volume, but had an advantage for overall desirability.

• Applied Biological Chemistry
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• v.13 no.3
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• pp.219-222
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• 1970

Riboflavin in the various materials which used for Takju brewing was determined and its quantitative changes in the Takju mashes which were mashed with polished rice and wheat flour respectively using Nuruk only for enzyme source, and with wheat flour and corn powder respectively using Nuruk and Koji, were checked at 24 hours intervals during the whole brewing period. The results obtained were as follows. a) The riboflavin contents in 100 grams of each materials were: Polished rice $46.9{\gamma}$ Wheat flour $67.3{\gamma}$ Corn powder $73.9{\gamma}$ Nuruk $169.0{\gamma}$ Koji of wheat flour $87.1{\gamma}$ Koji of corn powder $84.4{\gamma}$ b) About 30 to 40 percent of riboflavin in the polished rice, wheat flour and corn powder were losed by steaming at 10 pounds for 50 minutes. c) Riboflavin content in the plots used Nuruk only was decreased during 3 days after mashing and then increased markedly after 5 days and, more or less, decreased after 6 days. Quantitative changes of riboflavin in the plots used Nuruk and Koji showed a rugged curve without decreasing in early stages, and its content was also increased markedly 5 days after mashing and then decreased a little after 6 days. d) Approximately $82{\gamma}$ of riboflavin was determined in 100ml. of the ripened mash of the rice plot and $72{\gamma}$ in the wheat flour plot in the case of using Nuruk only. $88.6{\gamma}$ of riboflavin were determined in 100ml. of the ripened mash of the wheat flour plot and $83.6{\gamma}$ in the corn powder plot in the case of using Nuruk and Koji. e) It was assumed that $28.8{\gamma}$ to $41{\gamma}$ of riboflavin were contained in 100 ml. of finished Takju of the two plots used Nuruk only and 33.6 to 44.5${\gamma}$ in the both two plots used Nuruk and Koji. f) About $47.3{\gamma}$ of riboflavin were determined in 100 grams of Takju cake of the rice plot and $66.2{\gamma}$ in the wheat flour plot used Nuruk only, and $62.9{\gamma}$ in the corn powder plot and $64.5{\gamma}$ in the wheat flour plot used Nuruk and Koji.

• Journal of Microbiology and Biotechnology
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• v.20 no.9
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• pp.1322-1330
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• 2010

Three types of nuruk were made from rice, wheat, and a rice-glasswort (6:4) mixture. Nuruk, makgeolli, and vinegar were manufactured with rice nuruk (RN), wheat nuruk (WN), and rice-glasswort nuruk (RGN). The variable region of 18S or 16S rDNA amplified with genomic DNA extracted directly from nuruk-, makgeolli-, and vinegar-making cultures was analyzed via temperature gradient gel electrophoresis (TGGE). The sequence of the 18S rDNA variable region extracted from the TGGE gel for nuruk was 99% homologous with Aspergillus sp. and that for the makgeolli-making culture was 99% homologous with Saccharomyces sp. and Saccharomycodes sp. The sequence of the 16S rDNA variable region extracted from TGGE gel for the vinegar-making culture was 98% homologous, primarily with the Acetobacter sp. The eukaryotic and prokaryotic diversities in the nuruk-, makgeolli-, and vinegar-making cultures was not significantly altered by the addition of glasswort. Prokaryotic diversity was higher than eukaryotic diversity in the nuruk, but eukaryotic diversity was higher than prokaryotic diversity in the makgeolli-making culture, on the basis of the TGGE patterns. No 18S rDNA was amplified from the DNA extracted from the vinegar-making culture. The diversity of the microbial community in the process from nuruk to vinegar was slightly affected by the type of raw material utilized for nuruk-making. The saccharifying activity and ethanol productivity of nuruk, polyphenol content in makgeolli, and acetic acid and polyphenol content in the vinegar were increased as a result of the addition of glasswort. In conclusion, the glasswort may be not simply an activator for the growth of microorganisms during the fermentation of nuruk, makgeolli, or vinegar, but also a nutritional supplement that improves the quality of vinegar.