• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.11
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• pp.1829-1836
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• 2013

This study is carried out to investigate the physicochemical characteristics, microbial population, and sensory characteristics during fermentation of Korean traditional rice wine with addition of glutinous rice. The fed-batch fermentation of rice was performed by Nuruk and yeast for 10 days at $28^{\circ}C$ in a water bath. The four fermentation batches included 0, 10, 15 and 20% of glutinous rice based on the total rice contents. The growth of total viable cells, lactic acid bacteria (LAB), and yeasts were similar among the four batches during the fermentation period. The population for total viable cells and LAB were increased for the first 3 days, and decreased slowly until 10 days. The number of yeast cells was rapidly decreased after day 6, when the alcohol content reached about 15% for all the fermentation batches. Physicochemical characteristics, such as pH, total acidity, and reducing sugars, were not different with the increase of additional glutinous rice contents. The ethanol production was higher in Korean traditional rice wine from non-glutinous rice (17.1%) than ones from glutinous rice (15.8~16.7%). For the sensory evaluations, Korean traditional rice wine with 15% glutinous rice was highly preferred due to the highest sweetness.

• Korean journal of food and cookery science
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• v.22 no.6 s.96
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• pp.914-922
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• 2006

Korean traditional rice wines and liquors have been long brewed using nuruk or koji, cooked rice, How, yeast and some medicinal plants or herbs. The rosemary shrub (Rosmarinus officinalis L), belonging to the Labiatae family, is well recognized for its aromatic, antioxidant, antimicrobial and antitumoral properties. In this study, we investigated the effect of rosemary addition on the quality characteristics of Korean traditional rice wine. Wines containing different rosemary concentrations (0, 10, 20 or 30%) were ripened for 0, 5, 10, 15 and 20 days at 25C. The following quality characteristics were compared: pH, total acid, titratable acidity, amylase activity, color, reducing sugar amount, total sugar and ethanol. Although total acid increased, the pH of rosemary wine rapidly decreased during the rot 5-days of ripening, and these two changes were greatest in the wine containing 10% rosemary. The amount of both reducing sugar and ethanol in the wine rapidly increased during the rot 5-days of ripening, while total sugar content of rosemary wine decreased significantly with increasing ripening periods(p<0.05). According to the Hunter's color results, a significant color change in 'L' value was observed with increasing fermentation period in the wine containing 10% rosemary. Although 'a' value of control (0% rosemary liquor) increased during the ripening period, the addition of rosemary did not significantly affect 'a' or 'b' values. The transmittance of rosemary wines increased with increasing rosemary content but decreased throughout the ripening periods. Amylase activity decreased with increasing rosemary content, especially after a 5-day ripening period.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.1
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• pp.137-144
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• 2015

Kyejang is a Korean traditional beverage manufactured from medicinal plants and fruits using honey, sugar, or starch in cold water. In this study, cinnamon-containing kyejang, which is a type of beverage Jang, was reproduced based on Imwonsibyukji's method published in 1827 in the Korean literature. Kyejang made by nuruk, cinnamon, and medicinal plants was prepared at various temperatures and periods. Kyejang was assayed for physiochemical properties (pH and acidity), contents of metabolites (organic acids, sugars, and amino acids), and sensory characteristics (aroma and taste). During fermentation, content of organic acids (e.g. lactic acid, acetic acid, and shikimic acid) increased, which lowered pH, increased acidity, and increased intensity of sour taste. In the case of free sugars, fructose and maltose levels decreased while glucose and mannitol levels increased during fermentation periods, and sweetness decreased. The main amino acid in kyejang was tryptophan, followed by asparagine, proline, and arginine. The sensory evaluation score of overall preference was highest for kyejang which was fermented at $20^{\circ}C$ for 3 days. The results will be provide the basic data of fermentation conditions for standardized manufacturing process of kyejang.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.11
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• pp.1695-1700
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• 2014

Oriental herbal liquor (Yakju) is a type of Korean traditional alcoholic beverage that uses Nuruk and oriental herbs for fermentation. The purpose of this study was to develop cosmetic ingredients using Jubak, which is a by-product of alcoholic fermentation of oriental herbal liquor. To investigate antioxidant, whitening, and anti-aging effects of Jubak, we prepared extract of Jubak and its solvent fractions. Ethyl acetate fraction (KSD E4-3) showed the most prominent free radical [1,1-diphenyl-2-picrylhydrazyl (DPPH)] scavenging activity ($SC_{50}$: 0.75 mg/mL). KSD E4-3 significantly inhibited in vitro mushroom tyrosinase activity ($IC_{50}$: 0.82 mg/mL) and reduced the melanin contents in mouse melanoma melanocyte, B16F10 cells. KSD E4-3 down-regulated protein expression of tyrosinase related proteins (TRP)-1, -2, which play key roles in melanogenesis. For anti-aging effects, inhibition of matrix metalloproteinase (MMPs) expression was evaluated using human keratinocyte, HaCaT cells. Treatment of HaCaT cells with KSD E4-3 reduced expression of MMP-1, -2, -9 and inhibited proteolytic activities of MMP-2, -9. These results suggest that KSD E4-3 induces down-regulation of cellular melanogenesis and protects against photoaging induced by UVB-induced damage. Thus KSD E4-3 could potentially be a valuable cosmetic ingredient.

• Korean Journal of Food Science and Technology
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• v.52 no.5
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• pp.529-537
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• 2020

This study was carried out to confirm changes in the microbial community and physicochemical characteristics of Korean traditional Makgeolli during fermentation by yeast as a fermentation starter. We demonstrate that the microbial community during fermentation affects the quality of Makgeolli. At the species level, Pediococcus pentosaceus, Weissella confusa, Pantoea vagans, and Lactobacillus graminis were dominant on fermentation mix, after 1-2 days, in the control group without yeast treatment. Acid production in the control group was higher than that in the yeast-treated group. P. pentosaceus was dominant throughout the fermentation process, and the proportion of P. vagans remarkably decreased following yeast addition. Considering quality characteristics, the alcohol content rapidly increased after yeast addition, and the lactic acid content was lower in the yeast-treated group than in the control. These results suggest that the rapid increase in alcohol at the start of fermentation inhibits the growth of lactic acid-producing bacteria. The addition of yeast may contribute to the reduction in the high amount of lactic acid, which can be one of the causes of changes in Makgeolli quality.

• Korean Journal of Food Science and Technology
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• v.24 no.3
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• pp.272-278
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• 1992

Takju, a Korean traditional wine, was prepared by using nuruk and Koji which were inoculated with Aspergillus kawachii and Aspergillus shirousamii. Those chemical composition such as alcohols and organic acids were determined with gas chromatography to investigate the variation of its content by the fermentation. Alcohol such as methyl, ethyl, n-propyl, i-butyl, i-amyl alcohol were detected in the most takju mash samples. Alcohol contents in the groups fermented with KNR and SNR were slightly higher than KKR, SKR groups. Lactic acid were concentrated and organic acids such as pyruvic, oxalic, malonic, succinic, maleic, malic, ${\alpha}-keto$ glutaric acid were also detected in the most samples. The pH was lowest in the KKR group. The total acid content was slightly decreased at the later fermentation and was highest in KKR. The content of minerals were highest in the WNR and BNR groups. Throughout fermentation the content of potassium and magnesium varied greatly with the tested groups.

• Korean Journal of Food Science and Technology
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• v.43 no.2
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• pp.206-212
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• 2011

Makgeolli is Korean traditional alcoholic beverage that has historically been brewed. In this study, we analyzed the profile of organic acids in makgeolli and also evaluated its physiological characteristics. Makgeolli contained excess lactic acid, which is produced by lactic acid bacteria (LAB). Anti-obesity effects of makgeolli were investigated in 3T3-L1 preadipocytes. Compared to the negative control, makgeolli inhibited the differentiation of preadipocyte as quantified by Oil red O dye. In particular, $100{\mu}g/mL$ makgeolli reduced 40 to 70% of differentiation. To evaluate the anti-angiogenic and anti-inflammatory effects of makgeolli, we performed chorioallantoic membrane assay and measured nitric oxide production from lipopolysaccharide-induced RAW264.7 cells. Most makgeolli interrupted the formation of neo-vasculature and significantly inhibited NO production in a dose-dependent manner. Taken together, these findings suggest that commercial makgeolli has inhibitory activities against adipogenesis, neo-vascularization, and inflammation, and also they are influenced by second metabolites from nuruk microflora containing fungi and LAB.

• Korean Journal of Food Science and Technology
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• v.24 no.5
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• pp.440-446
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• 1992

Samil-ju, the traditional Korean rice wine was brewed and distilled using different columns (unpacked and packed) at different pressure (760, 460, 260 mmHg). Fractions of distillate were collected and analyzed. The sample wine, Samil-ju showed the following compositions; ethanol 14%, total acidity 16.2 g/100 ml, reducing sugar 7.9 mg/ml, total sugar 8.4 mg/ml, acetaldehyde 6 ppm, fusel oil acetaldehyde and ethyl acetate 6 ppm. As distillation proceeds, contents of ethanol, methanol, fusel oil, acetaldehyde and ethyl acetate were decreased but total acidity was increased. Generally at reduced pressure, all the constituents but total acidity showed more decrease than those at atmospheric pressure. In the 1st, 2nd and 3rd fractions of the distillate, ethanol contents were maintained at about 70% but those contents decreased abruptly to below 50% from the 5th fraction. Sixteen sensory characteristics were identified as quality factors of distillate. Among them, four characteristics were identified as aroma properties, seven as tastes and five as aftertastes. Nuruk and cooling flavor were considered as important factors which affect greatly the sensory quality of distillate. Among various fractions, the 2nd, 3rd and 4th fractions obtained from unpacked column at 260 mmHg showed the highest score in the overall quality. The compositions of these fractions were ranged as follows; methanol $24{\sim}36\;ppm$, total acidity $0.21{\sim}0.29\;g/100\;ml$, fusel oil 657-1340 ppm, acetaldehyde $12{\sim}41\;ppm$, and ethylacetate $22{\sim}311\;ppm$, respectively.

• KSBB Journal
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• v.19 no.4
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• pp.301-307
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• 2004

The characteristics of the a-amylase of Aspergillus coreanus NR 15-1 isolated from traditional Korean Nuruk have been carried out. The a-amylase of A. coreanus NR 15-1 was purified by ammonium sulfate precipitation followed by column chromatographies on CM-cellulose, DEAE-cellulose, Sephadex G-100 gel filtration and hydroxyapatite. The a-amylase was purified 78-fold with a yield of 8.7%. The molecular weight of the a-amylase was estimated to be 49 kDa by Sephadex G-100 gel filtration and 51 kDa by SDS-polyacrylamide gel eletrophoresis. These experimental results suggested that the purified enzyme might be monomer. The enzyme was stable between pH 4 and 11. The optimum pH was 5.0. The optimum temperature for enzyme was 45$^{\circ}C$ and the enzyme was stable up to 50$^{\circ}C$. The enzyme was significantly inhibited by 1 mM N-bromosuccinimide. These results suggested that tryptophan residue was involved in the active site of a-amylase. The enzyme was identified as a-amylase because the reaction products of soluble starch hydrolyzed by the purified enzyme was oligosaccharide by thin layer chromatography.