• Advances in Traditional Medicine
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• v.5 no.3
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• pp.216-230
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• 2005

Although the field of study in immune enhancing compounds is relatively new, natural products from plants represent a rich and promising source of novel molecules with immunomodulating properties, Microglial cells, the main immune effector cells of the brain, usually display a ramified morphology and low expression levels of immunologically relevant antigens such as MHC class I and class II. Since any compound which participates in activation of phagocytic cells contributes to the production of potentially toxic factors, the search for convenient in vitro test-systems and study of mechanisms of action of these agents are of great interest. Human blood polymorphonuclear (PMN) cells and primary microglial cells isolated from Sprague-Dawley rats were used as cellular screening tests for study of phagocytosis-stimulating action of immunomodulating agents. Numbers of phagocytic activity were evaluated by the phagocyte ingestion of yeast cells and NO-synthase activity, nitrite production, and nitroblue tetrazolium test were determined after phagocyte stimulation. It was possible to demonstrate that indexes of phagocytic activity can be used as quantitative indicators for measurement immunomodulating activity. As a positive control, Zymosan A-induced phagocytosis in both PMN cells and primary microglial cells was used. $IFN-{\gamma}$ (0.1 -1 U/ml) stimulated phagocytosis in PMN cells 1.2 times after 2 - 3 h incubation, although at higher concentrations (10 - 100 U/ml) it strongly inhibited phagocytosis. In a similar way, at higher concentrations, $IFN-{\gamma}$ (100 - 500 U/ml) suppressed phagocytosis in zymosan-A stimulated microglial cells. When Polypodium leucotomus, cambricum and vulgare extracts were tested alone, increased levels of phagocytosis were observed in PMN. In addition, microglial cells showed both increased phagocytosis and MHC class-II antigen expressions. Surprisingly, when PMN and microglia were treated with a combination of Polypodium and $IFN-{\gamma}$, phagocytosis was not inhibited. We did not find changes in NO-synthase activity and nitrite production in both microglia and PMN cells activated by different immunomodulating agents. These results indicate that primary microglial cell cultures as well as human PMN cells can provide reproducible quantitative results in screening phagocytic activity of different immunoactive compounds. Furthermore, both inhibitory or activation mechanisms might be studied using these in vitro experimental approaches.

• Microbiology and Biotechnology Letters
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• v.38 no.1
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• pp.46-52
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• 2010

Yakju, a Korean traditional alcoholic beverage, is made from glutinous-rice flour or rice starch with nuruk. In this study, we investigated that fermentation characteristics in yakju was made with glutinous rice and pretreatment. The yeast and nuruk were used Y90-9 and SP1800 (a kind of improved nuruk), respectively. pH and brix degree of yakju, brewed with glutinous rice flour by heating, were higher than the others during fermentation process. Total acid contents were 0.2~0.3 and the highest alcohol degree (15.75%(v/v)) was fermented glutinous rice flour by heating. Reducing sugar contents were 3.5-3.9 mg/mL. Yakju, which brewed with glutinous rice flour, of amino acid degree, UV absorbance and color degree was higher than yakju which brewed with glutinous rice starch. Succinic acid was the highest organic acid among 6 organic acids and free sugar contents described as glucose > maltose > fructose. Twenty one components were identified including 3 alcohols, 17 esters and one aldehyde. Of these, ethyl palmitate, which was described as mild flavor, was the highest %area except ethyl alcohol. Overall, the fermentation performed using glutinous rice flour by heating and improved-nuruk showed the best results for yakju production.

• Applied Biological Chemistry
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• v.45 no.3
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• pp.138-144
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• 2002

In order to improve the quality of foxtail millet wine, zymological properties by isolated strains from Nuruk were investigated. Saccharomyces sp Y5-1 as brewing yeast, Aspergillus sp. M6-3, Aspergillus awamori 6970, and Aspengillus usamii mut. shirousamii 6959 (KCTC) as saccharifying molds were used, respectively. Acid content, soluble solids, color (b) and alcohol contents were increased during fermentation. Ethanol concentration of millet wine made with Nuruk by Aspergillus awamori 6970 and Aspergillus usamii mut. shirousamii 6959 were higher than the other, 10.6 and 10.1% respectively. Citric acid was only detected on $1{\sim}2$ day starting fermentation. Oxalic acid, lactic acid and acetic acid of millet wine were high in the wine made of Nuruk by Aspergillus usamii mot. shirousamii 6959, Aspergillus awamori 6970 and traditional Nuruk, respectively. During fermentation, glucose and xylose was higher than the others. Xylose was increased, but most of other sugar were decreased during fermentation. Acetone, ethyl acetate, methanol, ethanol, n-propanol, iso-buthanol and iso-amyl alcohol were detected In the wine made with Nuruk by Aspergillus awamori and Aspergillus usamii mut. shirousamii, iso-imyl alcohol and ethanol were high. On sensory evaluation, the wine made with Nuruk by Aspergillus usamii mut. shirousamii was the best on color and taste.

• Microbiology and Biotechnology Letters
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• v.35 no.3
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• pp.231-237
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• 2007

To support the fermentational superiority of Korean nuruks and maintain the various domestic nuruks, the optimal nuruk production of Andong-Soju, which was designated as an intangible cultural asset of Gyungsangbukdo province from 1987, was investigated. Different thickness of nuruks ($2.2{\sim}5.5\;cm$) were manufactured based on traditional Andong-Soju nuruk method, while the size of round form of nuruk was set to 23 cm. During the 3 weeks maturation, changes of water content, weight, pH, brix, the amount of reducing sugar, sac-charifying activity, viable cell and major microorganisms were determined, Also, ethanol fermentation abilities of the manufactured nuruks were evaluated using 20% glucose medium or 16% starch medium, respectively. Our results indicated that the production of high quality of Andong-Soju nuruk needs $4.0{\sim}5.5\;cm$ thickness and 3 weeks maturation without extraneous yeast addition. These results would be applied to production of homogeneous, and high quality of Andong-Soju nuruk.

• Microbiology and Biotechnology Letters
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• v.42 no.4
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• pp.407-412
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• 2014

A number of Saccharomycopsis fibuligera strains that can hydrolyse and utilize starch as a carbon source were isolated from nuruk, a traditional Korean starter for rice wine fermentation, and their specific growth rates on starch-containing medium were compared to choose the prominent strain. S. fibuligera strain MBY1320 showed a higher growth rate at $42^{\circ}C$ than that of strain S. fibuligera KCTC7806, indicating that S. fibuligera MBY1320 has more thermo-tolerant machinery for starch hydrolysis and utilization than KCTC7806. Although the activity of ${\alpha}$-amylase at $30^{\circ}C$ was significantly lower for S. fibuligera MBY1320 than KCTC7806 (3,812.5 U vs. 14,878.5 U), S. fibuligera MBY1320 showed a much higher glucoamylase activity at $42^{\circ}C$ than S. fibuligera KCTC7806 (5,048.9 U vs. 13,152.3 U). Thus, a new S. fibuligera strain, with a higher starch-hydrolysing activity at elevated temperatures than that of other types of strain, this study reports.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1350-1357
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• 2000

Traditional Kochujang was prepared adding horseradish or mustard powder to repress the gas formation which used to cause swelling problem during distribution. The koji for Kochujang was prepared by the strains which had high amylase and protease activities with superior flavor. The gas production from Kochujang during fermentation at $25^{\circ}C$ was ceased after stopping yeast growth completely by bactericidal components from $0.6{\sim}1.2%(w/w)$ of horseradish or mustard addition. Total viable bacterial count was not affected by adding horseradish or mustard. The amino type nitrogen content in Kochujang, which was one of the most important parameters in quality of Kochujang, increased continually during fermentation. The Kochujang fermented by P-2 isolate and added with mustard was significantly higher in amino type nitrogen content than other treatments after 120 days' fermentation. ${\alpha}-Amylase$ activity was very low while ${\beta}-amylase$ activity was high in Kochujang fermented by adding horseradish and mustard powder. The protease(acid and neutral) activities gradually increased by fermentation with no difference between treatments. The color and flavor were not different, but overall palatability of the Kochujang evaluated by sensory test showed significantly high rank in Kochujang fermented by P-2 isolate and with horseradish.

• Food Engineering Progress
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• v.14 no.4
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• pp.346-353
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• 2010

Due to the globalization of Korean foods, there are great interests in traditional Korean foods. Thus, the enhancement and development of makgeolli processing have been constantly accomplished. In case of makgeolli, the storage stability is very important because the fermentation of makgeolli during distribution is still progressed. Therefore, the objective of this study was to investigate storage stability of makgeolli by separation storage methods. During the 30-day storage at $10^{\circ}C$, pH value, titratable acidity, color value, sugar content, reducing sugar content, and alcohol content were measured. Microbial cell counts were also evaluated. Reducing sugar content was decreased after 10 days for all the samples. In the case of titratable acidity and color, these values were constantly increased with storage time. Especially, the yellowness value of the precipitate of makgeolli was increased by two times than that of the beginning. There was a decreasing tendency for lactic acid bacteria with storage time. In case of yeast, there was a decreasing tendency after 15 days, but the significance was not detected. The quality changes in the samples from centrifugal separation were relatively less than the control. Therefore, the separation storage method could affect the enhancement of makgeolli quality during distribution.

• Microbiology and Biotechnology Letters
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• v.39 no.1
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• pp.56-62
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• 2011

We investigated quality characteristics of Seoktanju (one of the Korean traditional rice wine) which was fermented using five kinds of Korean commercial Nuruks. The purpose of this study was to research what effects on the quality of Seoktanju by using different Nuruks. We analyzed general component such as each mash's temperature change patterns, pH, titrable acidities, reducing sugar contents, volatile acids, and sugar contents during fermentation periods and studied sensory evaluation of produced Seoktanju (10 days). On the whole, temperature change patterns in the each mashes were depend on room temperature. All Seoktanju's pH was reduced rapidly up to three days after first mashing (pH 3.13-3.57) and after that was increased gradually. The end of fermentation pH was pH 3.6-4.05. Mostly, acidities were indicated high(0.59%) and Nuruk-B was showed highest acid value. These results seems to be different as occasion organic acids producing activity depend on the number of yeast, material contents, optimal temperature in the each mashes by fungi and lactic acid bacteria in Nuruks. In reducing sugar contents and sugar contents, Nuruk-C treatment were showed the highest value with 5.36%, $23^{\circ}brix$, respectively and alcohol content was lowest with 8.6%. In the five kinds of reproduced Seoktanju, alcohol content was the highest in the treated Nuruk-A group. Volatile acid value was the highest with 132.6~263.7 ppm at the 3 day after first mashing day but as the fermentation time goes on, it was reduced sharply by 5.25~5.94 ppm. Sensory evaluation was performed with 5 point scale, the Seoktanju using Nuruk-D was presented by 4 point, while Nuruk-A was presented lowest by 2.77 point on overall acceptability.

• Korean Journal of Food Science and Technology
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• v.50 no.4
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• pp.407-413
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• 2018

The current study reviews the manufacturing characteristics, upon aging, using different distillation methods with Saccharomyces cerevisiae 88-4 isolated from traditional Nuruk. The alcohol content slightly decreased at 180 days of aging period, under the conditions: -60 cmHg, distilling temperature $50^{\circ}C$, head cut 7%, and body cut 30%. The alcohol content decreased by 2.2% at: -50 cmHg, distilling temperature $60^{\circ}C$, head cut 7%, and body cut 30%. From 2-thiobarbituric acid (TBA) analysis, the TBA values were not found to change significantly in most of the alcohols, but increased at conditions of: -60 cmHg, distilling temperature $60^{\circ}C$, head cut 7%, and body cut 50% and -50 cmHg, distilling temperature $50^{\circ}C$, head cut 7%, and body cut 50%, when initial alcohol levels were low. According to n-propanol, iso-butanol, and isoamyl alcohol analysis, with increasing aging period, the n-propanol and isoamyl alcohol content did not change, although that of iso-butanol decreased. The flavor components showed different results based on the aging period. Results of sensory evaluation showed no significant difference based on aging. The sensory evaluation test was continued for 180 days at a condition of: -60 cmHg, distilling temperature $60^{\circ}C$, and body cut 50%, which had the best overall evaluation ($5.8{\pm}0.9$).

• 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.