• Korean Journal of Food Science and Technology
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• v.49 no.3
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• pp.279-285
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• 2017

This study reviews the manufacturing characteristics of distilled liquor prepared using Saccharomyces cerevisiae 88-4 separated from traditional Nuruk. From analysis of soju mash (sool-dut) during the fermentation process, 17.2% of alcohol was detected in the final fermentation with succinic acid present at the highest level ($7,164.3{\pm}85.2ppm$). From the analysis of alcohol content in different distillation conditions, distillation condition No. 6 showed the lowest amount of alcohol ($29.6{\pm}0.0%$), whereas distillation condition No. 4 showed the highest amount ($59.9{\pm}0.1%$). N-propanol has been detected at the highest level in distilled liquor under conditions No. 1 and 4, each being $163.4{\pm}18.3$ and $174.0{\pm} 0.1ppm$, respectively. Isobutanol showed a tendency similar to n-propanol. Distilled liquor in conditions No. 1 and 4 has shown the highest acetaldehyde level, each being $303.4{\pm}4.5$ and $325.4{\pm}13.1ppm$, respectively. After distillation, 14 volatile substances were found in common, with isoamyl alcohol present at the highest levels in all the distilled liquors. Distillation conditions No. 3, 5, 6, and 7 have shown high levels of isobutanol that emits a banana-like fragrance and ethyl octanoate that emits a pleasant fruity and floral fragrance.

• Applied Biological Chemistry
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• v.13 no.1
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• pp.105-109
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• 1970

Thiamin in the various materials which used for Takja braving was determined and its quantitative changes in the Takju mashes which were mashed with polished rice and wheat flour respectively using Nuruk only for the 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 thiamin contents in 100 grams of each materials were: Polished rice 107.8${\gamma}$ Wheat Pour 185.0${\gamma}$ Corn powder 410.2${\gamma}$ Nuruk 347.4${\gamma}$ Koji of wheat flour 170.1${\gamma}$ Koji of corn powder 257.3${\gamma}$ b) About 40 to 50 percent of thiamin in the polished rice, wheat flour and, corn powder were losed by steaming at 10 wounds for 50 minutes. c) The quantitative changes of thiamin in the Takju meshes showed a similar tendency. Thiamin contents were decreased markedly during 2 days after mashing but thereafter, almost unchanged till the mashes were ripened. Its decreasing rates in tile two plots uses Nuruk and Koji wereless thaw those in the two plots used Nuruk only. d) Approximately 6${\gamma}$ of thiamin was determined in 100 ml. of the ripened mash of the rice plot and 7.5${\gamma}$ in tire whet flour plot in the case of using Nuruk only. 12.4${\gamma}$ of thiamin was determined in 100 ml. of the ripened mash of the wheat flour plot and 15.4${\gamma}$in the corn powder plot in the case of using Nuruk and Koji. e) It was assumed that 2.4 to 3.5${\gamma}$ of thiamin were contained in 100 ml. of finished Takju of the two plots used Nuruk only and 5 to 7${\gamma}$ in the two plots used Nuruk and Koji. f) About 43.7${\gamma}$ of thiamin were determined in 100 grams of Takju cake of the rice plot and 56.1${\gamma}$ in the wheat flour plat used Nuruk only, and 81.4${\gamma}$ in the corn powder plot and 57.7${\gamma}$ in the wheat flour plot used Nuruk and Koji.

• The Korean Journal of Mycology
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• v.6 no.1
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• pp.29-41
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• 1978

This study aims to brew apple wine containing lower concentration of alcohol by fermentation and to retain $CO_2$ gas in apple wine, and investigation for the possibility of storage at room temperature was performed. A Saccharomyces sp. was proved to be acceptable for production of base wine as its higher fermentation rate at $20{\sim}25^{\circ}C$. However, B-2 was most reasonable for post-fermentation of apple wine as this strain strongly ferments sugars at low temperature $(4^{\circ}C)$. The yield of apple juice increased by maceration of apple pulps. The yield was about 5 % more than that of the unmacerated juice, whereas acid content was decreased by 10% compared with control. When stored apple wine containing 9% alcobol was introduced $1{\sim}3%$ sucrose at $7{\sim}8^{\circ}C$ for 100 days or more, the $CO_2$ pressure of apple wine in bottle shows $3kg/cm^2$ by bottle-pressure meter. It showed good storage of the wine at room temperature. $CO_2$ gas pressure in apple wine containing 6% alcohol, $5{\sim}10%$ hop extract, and 2% sugar was $2kg/cm^2$, he result also showed possibility of storage. Whereas 6% concentration of alcoholic apple wine without hop extract caused unusual fermentation during storage at the same condition. The desirable conditions for high quality apple wine should have $CO_2$ pressure of $2kg/cm^2$ or more and should be added $1{\sim}2% sugar to base wine. From these results, it can be concluded that the brewing of lower alcoholic apple wine is possible.

• Food Science and Preservation
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• v.20 no.4
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• pp.564-572
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• 2013

We investigated the quality characteristics of brewing brown rice vinegar through a traditional static fermentation process. Accordingly, we decided to compare the physicochemical characteristics of brewing vinegar at different temperatures and filtration methods. In four to five weeks' time, the acetic acid fermentation exhibited the highest titratable acidity and then it eventually decreased. The titratable acidity was affected by the filtration method. It was revealed that the titratable acidity was higher in the forced filtration than the traditional filtration method. Various organic acids were detected in order to initialize the fermentation stage and as the fermentation progressed, only the acetic acid could be detected. The total free amino acid content was higher at a temperature of $30^{\circ}C$ than at $20^{\circ}C$. Moreover, the free amino acid content was dependent on the acetate content during the acetic fermentation process. The main bioactive substance of the ${\gamma}$-aminobutyric acid content was more than twice at a fermentation temperature of $30^{\circ}C$ compared to the fermentation temperature of $20^{\circ}C$. Furthermore, the total amino acid and essential amino acid content at a temperature of $30^{\circ}C$ was excellent. The quality of the brown rice vinegar via forced filtration method at a temperature of $30^{\circ}C$ was the most excellent. Based on these results, the fermentation temperature and the use of nuruks (fermenting agent) affected the quality of the brown rice vinegar, and an appropriate method to consider its purpose is required.

• Applied Biological Chemistry
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• v.22 no.3
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• pp.160-165
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• 1979

This study was carried out to investigate effects of iron content on the quality of soy sauce, bean paste and red pepper paste, and to elucidate the origin of iron and change of the contents during production processes. For the first step, the iron contents in commercial soy sauce and changes of the contents during brewing process were determined. The results obtained were as follows. 1, Iron contents of raw materials were 108 ppm in soy bean, 133ppm in defatted soy bean, 79 ppm in wheat, 5 ppm in sodium chloride, 58 ppm in seed koji, 300-2000 ppm in spore of Aspergillus oryzae, 240 ppm in wheat gluten, 20 ppm in sodium carbonate (above figures were of dry weight basis), 6 ppm in hydrochloric acid, 18 ppm in caramel and 0.3ppm in brewing water respectively. 2, Iron contents in koji were 200-240 ppm (as dry weight basis) and increased, more or less, in progress of koji-making period. 3. Iron contents in the mashes during fermentation were 40 rpm after 1 month, 43-47 ppm after 3 months and 49-62ppm after 6 months. 4. In chemical soy sauce, the iron content was 159 ppm after hydrolysis of wheat gluten with hydrochloric acid, and 184 ppm after neutralization. 5. Higher iron contents were detected both in fermented and chemical soy sauce when the concentration of total nitrogen increased, but the levels were higher in chemical soy sauce than in fermented one at the same concentration of total nitrogen. 6. In the case of fermented soy sauce, the iron content in the filtrate was decreased by press-filtration, but no significant change was found between before and after heat-sterilization. 7. Iron contents in commercial soy sauce were varied with the producers, however, the average value was 62.7 ppm as calculated as 1.0 percent of total nitrogen. And the average level of iron in home-made soy sauce produced by conventional method was 37.68 ppm.

• Korean Journal of Food Science and Technology
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• v.49 no.4
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• pp.383-389
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• 2017

This study aimed to select a yeast strain for optimizing the quality of distilled spirits. The brewing and distilling properties of 4 KFRI (Korea Food Research Institute) yeasts (Y88-4, Y98-4, Y172-6, Y192-4) and 2 industry yeasts (C1, C2) were compared. For investigating the possibility of using these strains on an industrial scale, diverse analytical methods were applied to assess parameters associated with distilled spirit quality such as alcohol content, pH, total acidity, and soluble solid content. After 11 days of fermentation, the alcohol strength obtained using six yeast strains reached 13.9-16.4% (v/v), while pH was 3.9-4.0, and total acid was 0.40-0.52%. To compare GC-MSD Volatile flavor components, all the distilled spirit samples were diluted to 20% (v/v) alcohol strength. Seven fusel alcohols, 26 esters, 2 acids, and 3 miscellaneous compounds were detected in the distilled spirits. Y88-4 had the most abundant volatile flavor component and scored the highest overall preference in sensory evaluation. After analyzing the various properties of yeasts, strain Y88-4 was finally selected as the best strain for producing distilled spirits.

• Mycobiology
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• v.40 no.2
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• pp.117-123
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• 2012

Nuruk contributes to the unique characteristics of Korean alcoholic beverages. In this study, the effects of nuruk extracts (NE) on anti-oxidant characters, melanogenesis, and anti-photoaging activity were investigated. NEs were obtained from the 70% ethanol extracts of six types of nuruk, which have been used in brewing of fermented alcohol beverages in Korea. First, various antioxidant characteristics were identified in terms of 2,2'-azino-bis(3-ethylbenzthiozoline-6-sulphonic acid) (ABTS) radical scavenging activity, superoxide dismutase (SOD) expression, and inhibition of xanthine oxidase activity. NE#4 exhibited potent ABTS radical scavenging activity ($IC_{50}$ = 19.51 ${\mu}g$/mL). Compared with NE#4, relatively lower levels of activity were observed for NE#3 and NE#6, with $IC_{50}$ values of 90.99 and 76.88 ${\mu}g$/mL, respectively. According to results of western blot analysis for determination of SOD expression in $H_2O_2$-treated HepG2 cells, NE#5 and NE#6 induced a dramatic increase in the expression ratio of SOD, compared to the group treated with $H_2O_2$ only. Activity of xanthine oxidase, which converts xanthine into uric acid, generating superoxide ions, was inhibited by NE#4 and NE#6 in a dose-dependent manner. NE#4 induced significant inhibition of mushroom tyrosinase activity. A reduction in cellular melanin contents of 80% was observed in B16F1 melanocytes treated with NE#5 and NE#6; these effects were similar to those of arbutin at 100 ${\mu}M$. In addition, gelatin zymography and reverse transcription-PCR analysis were performed for assessment of anti-photoaging activity of Nuruk. Treatment with NE#6 resulted in dramatically inhibited activities of matrix metalloproteinase (MMP)-2/-9, suppressed expression of MMP-1, and increased expression of type-1 procollagen. Results of gelatin zymography for NE#4 and NE#5 were similar, to a slightly lesser degree. These results suggest the potential of NE#4 and NE#6 as natural ingredients for use in functional foods and cosmetics.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.8
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• pp.1219-1225
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• 2015

This study was carried out to compare quality characteristics and physiological activities of Korean traditional wines fermented by addition of puffed sorghum powder. Using a two-step brewing process for fermented wines, pH, acidity, ethanol, color, tannin, ${\alpha}-glucosidase$ activities, antioxidant, and reducing sugar levels as well as sensory evaluation were measured during fermentation at 2-day intervals until day 8. The pH levels of fermented wines ranged from 4.07 to 5.53, and acidity ranged from 0.13 to 0.86. On the last day of fermentation, alcohol contents of control, raw sorghum, steamed sorghum, and 25, 50%, and 100% puffed sorghum were 16.8%, 11.7%, 13.4%, 16.5%, 15.2%, and 16.4%, respectively. The reducing sugar and ${\alpha}-glucosidase$ activities of puffed sorghum fermented wines were relatively higher than those of the control group, whereas those of steamed sorghum were lowest. As puffed sorghum powder content increased, antioxidant activity significantly increased. In the results of the sensory evaluation, overall preference of 50% puffed sorghum fermented wines was highest among the samples. The results of this study show that physiological activity and quality characteristics of fermented wines containing puffed sorghum powder contribute to value added improvement of sorghum processing.

• Journal of Applied Biological Chemistry
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• v.55 no.3
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• pp.163-167
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• 2012

The objective of this study was to determine the effects of Schisandra chinensis on the alcohol fermentation of Korean traditional rice wine 'Yakju', using various methods including alcohol contents, Hunter's color value, organic acid contents, pH value, and sugar contents. The observed results differed according to dosage and fermentation. The S. chinensis Yakju contained various organic acids such as citric, formic, lactic, malic, oxalic acid, shikimic, and succinic acids. In particular, the citric acid contents of S. chinensis Yakju were 9.22, 161.38, 339.28, 458.97, and 634.96 mg/100 mL at doses of 0, 5, 10, 15, and 20% (v/v) of S. chinensis, respectively. The pH of S. chinensis Yakju ranges from 4.11 to 3.57 according to the ratio of S. chinensis. As a result, the citric acid content and pH of S. chinensis Yakju were dependent on the concentration of S. chinensis. On the basis of the Redness value, the S. chinensis Yakju after fermentation (5.16) was approximately 1.8 times more effective than that before fermentation (2.86) at the concentration of 20% (v/v) of S. chinensis. However, S. chinensis has little or no influence on the sugar and alcohol contents of Yakju. These results indicated that S. chinensis was more efficient for improvement of quality characteristics of Yakju.

• The Korean Journal of Mycology
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• v.41 no.4
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• pp.255-260
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• 2013

In order to develop new valuable pear marc nuruk and further, reduce environmental pollution by pear marc from pear juice processing, we prepared pear marc nuruk by incubation of Aspergillus oryzae into pear marc containing 50% of moisture at $30^{\circ}C$ for 7 days. ${\alpha}$-Amylase and glucoamylase activities of the pear marc nuruk were 320.2 IU and 442.8 IU, respectively and its acidic protease activity was showed 142.6 IU. After brewed makgeolli by using the pear marc nuruk, cooked rice and Saccharmyces cerevisiae, its physicochemical characteristics was investigated. Ethanol content of pear marc nuruk-makgeolli was 6.8% after fermentation at $25^{\circ}C$ for 10 days and also pear marc makgeolli showed 45.6% of antihypertensive angiotensin I-converting enzyme (ACE) inhibitory activity. In conclusion, pear marc nuruk had high amylase activity and pear marc-makgeolli had also good fermentation characteristics and antihypertensive ACE inhibitory activity. Therefore, it has the potential to become a new nuruk for brewing makgeolli.