• Journal of Biosystems Engineering
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• v.43 no.3
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• pp.229-236
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• 2018

Purpose: Makgeolli is a traditional alcoholic beverage made from rice with a fermentation starter called "nuruk." The concentration of alcohol in makgeolli depends on the temperature of the fermentation tank. It is important to monitor the alcohol concentration to manage the makgeolli production process. Methods: Data were collected from 84 makgeolli fermentation tanks over a year period. Independent variables included the temperatures of the tanks and the room where the tanks were located, as well as the quantity, acidity, and water concentration of the source. Software for the multilayer perceptron model (MLP) was written in Python using the Scikit-learn library. Results: Many models were created for which the optimization converged within 100 iterations, and their coefficients of determination $R^2$ were considerably high. The coefficient of determination $R^2$ of the best model with the training set and the test set were 0.94 and 0.93, respectively. The fact that the difference between them was very small indicated that the model was not overfitted. The maximum and minimum error was approximately 2% and the total MSE was 0.078%. Conclusions: The MLP model could help predict the alcohol concentration and to control the production process of makgeolli. In future research, the optimization of the production process will be studied based on the model.

• The Korean Journal of Mycology
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• v.39 no.2
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• pp.122-125
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• 2011

The goal of this study was to provide shelf-life of Gugija-Liriope tuber raw makgeolli. After we prepared Gugija-Liriope tuber raw makgeolli by using Gugija, Liriope tuber, nuruk, cooked rice and Saccharomyces cerevisiae C-2, changes of its quality and physiological functionality were investigated during the storage at $4^{\circ}C$ and $20^{\circ}C$. Ethanol contents was decreased from 8.3% to 7.2% for storage of 9 days at $4^{\circ}C$ and 6 days storage at $20^{\circ}C$, respectively. Antihypertensive angiotensin I-converting enzyme inhibitory activity of Gugija-Liriope tuber makgeolli was increased from 63.1% to 66.0% after storage for 9 days at $4^{\circ}C$. Total acceptability of 9 days storage makgeolli at $4^{\circ}C$ was still good. In conclusion, shelf-life of Gugija-Liriope tuber raw makgeolli was 9 days at $4^{\circ}C$ in this respect of ethanol contents, antihypertensive action and total acceptability.

• Korean journal of food and cookery science
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• v.27 no.5
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• pp.577-587
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• 2011

In this study, lotus leaf was added to a Takju (Korean milky rice wine) preparation to evaluate its effects on physicochemical and fermentation properties. For rapid saccharification Takju was stored at 25$^{\circ}C$ for 2 days and then temperature was switched to 18$^{\circ}C$ to mature the wine for 21 days. From the start of fermentation to 2-days, the pH of Takju decreased rapidly and acidity increased. Maltose, a byproduct of starch saccharification, increased for 2 days then rapidly decreased. Glucose fluctuated for 7 days and of the 21-days fermentation. The ethanol production rate was highest during the first 7 days, then slowed. Total viable yeast and lactic acid bacterial counts increased rapidly for 2 days and then decreased gradually thereafter. Leuconostoc spp. grew rapidly for 1 day and sharply disappeared with decreasing pH. DPPH radical scavenging activity was significantly higher for Takju prepared with lotus leaf than without. The overall acceptance of Takju tended to increase when it was prepared with lotus leaf.

• Korean Journal of Food Science and Technology
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• v.42 no.4
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• pp.468-474
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• 2010

Alcoholic fermentations with rice koji [Aspergillus awamori Nakazawa KCCM 60246 (black), Aspergillus kawachii KCCM 32819 (white), Aspergillus oryzae KCCM 11372 (yellow)] and improved nuruk were carried out for the preparation of sweet potato soju using two different potato cultivars (Jinhongmi and Hobak). The Jinhongmi mashes showed $9.2-11.4^{\circ}Brix$, 195.6-260.5 mg glucose/100 mL, pH 4.6-4.9, 0.53-0.83% acidity and 13.2-16.2% alcohol content. The Hobak mashes showed $7.0-8.4^{\circ}Brix$, 31.9-47.4 mg glucose/100 mL, pH 4.4-4.7, 0.22-0.24% acidity, and 9.6-11.2% alcohol content. The alcohol yield of the Jinhongmi mashes using black, white, yellow koji and improved nuruk were 229.2, 194.5, 238.6 and 229.3 L/ton, respectively. The alcohol yields of Hobak mashes using black, white, yellow koji and improved nuruk were 132.8, 144.4, 141.6 and 167.4 L/ton, respectively. All types of sweet potato soju showed stronger flavor and taste than Kurokirishima (Japanese sweet potato soju). Especially, soju made from Jinhongmi with white koji and Jinhongmi with improved nuruk showed the strongest levels. Flavor components of sweet potato soju included decanoic acid ethylester, dodecanoic acid ethylester, tetradecanoic acid ethylester, hexadecanoic acid ethylester, 9-octadecanoic acid ethylester, and octadecanoic acid ethylester. Although the flavor profiles of Jinhongmi soju, Hobak soju, and Kurokirishima were very similar, the flavor content of Kurokirishima soju was lower. The results of the GC volatile analysis were in good correlation with flavor and taste.

• Korean Journal of Food Science and Technology
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• v.43 no.6
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• pp.742-746
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• 2011

To increase the quality of Korean traditional yakju, we prepared seed cultures by fermentation at $20^{\circ}C$ for 2 days after addition of 140% water, 3% nuruk and 1.5% yeast into cooked rice. After the 200% cooked rice, 120% water and 0.08% commercial saccharifying enzyme were added to seed cultures and fermented for 2 days at $20^{\circ}C$, wild ginseng was added and then further fermented for 5 days. Physicochemical properties of traditional yakju were investigated. Ethanol was produced (18.5%) by the addition of 1.2% wild ginseng. However, ethanol content was not increased by addition of microwave treated-wild ginseng and rice (either cooked rice or raw). The traditional yakju obtained by fermentation at $20^{\circ}C$ for 5 days, after 90 sec of microwave treated-wild ginseng was added into main fermentation broth, showed good total acceptability and also contained 791 ppm saponin.

• Journal of Life Science
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• v.24 no.8
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• pp.843-850
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• 2014

In the current study, we prepared eighty-five different kinds of solvent fractions of rice wine lees and nuruk extracts and investigated their effects on cell viability and nitric oxide (NO) production in mouse RAW 264.7 cells. Among the treated solvent fractions, only three solvent fractions (KSD-E1-3, KSD-E2-3 and KSD-E4-3) significantly decreased NO production in LPS-activated RAW 264.7 cells without affecting cell viability. And, they also reduced the expression of pro-inflammatory genes such as COX-2, TNF-alpha and iNOS. To understand the molecular mechanisms involved in the inhibition of inflammation in (KSD-E4-3)-treated RAW 264.7 cells, we carried out oligo DNA microarray analysis using Agilent Mouse microarray. To confirm microarray data, 6 genes (IL-1F6, iNOS, IL-10, Fabp4, IL-1RN and CSF2) were selected and performed RT-PCR and quantitative real-time PCR analysis with gene specific primers. The results of RT-PCR and real-time PCR agreed with microarray data. Overall, our results suggest that rice wine lees can be a novel resource for the development of foods and drugs which possess anti-inflammatory activity.

• Korean Journal of Food Science and Technology
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• v.50 no.4
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• pp.400-406
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• 2018

Takju and yakju are traditional Korean alcoholic beverages that are prepared by fermentation of glutinous rice with nuruk, a cereal starter containing various bacteria, fungi, and yeast. In this study, physicochemical and microbial properties of a total of 12 commercial takju and yakju samples were analyzed; their pH, sweetness, and alcohol content were varied, depending on the type of alcohol, from pH 3.64-4.8, $5.1-24.8^{\circ}Bx$, and 4.6-18.5%, respectively. Microbial communities were analyzed with 16S rRNA amplicon sequencing using MiSeq system. At the phylum level, Firmicutes (86.2%) was the most dominant, followed by Proteobacteria (8.08%), Actinobacteria (2.56%), and Cyanobacteria (3.13%). Lactic acid bacteria, including Lactobacillus, Lactococcus, Leuconostoc, and Weissella were also frequently detected. Among eukaryotes, Saccharomyces cerevisiae was the most dominant in these samples.

• Korean journal of food and cookery science
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• v.28 no.4
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• pp.383-390
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• 2012

In order to reproduce Sanghwabyung that people in the past made and ate at Yuduil (June 6th by lunar calendar) among our traditional rice cakes, this study manufactured Sanghwabyung with black wheat flour by adding the wheat bran and Nuruk powder as leavening source, according to the old cook book "Gyuhapchongseo" and analyzed the quality characteristics. As a result of total phenol and flavonoid contents, DPPH radical scavenging activity of black wheat contents showed the gradual increase significantly (p < 0.001). The number of lactic acid bacteria was $6.72{\times}10^7$ CFU/mL just after preparation, and the number of yeast was $5.59{\times}10^7 $ CFU/mL. The number of lactic acid bacteria and yeast increased after 24 h to $8.48{\times}10^7$ CFU/mL and $5.40{\times}10^7$ CFU/mL. Hard-ness was the lowest in WF30%, compared with the C and the highest in BF100% and WF100%. The more the added portion increased in WF30% and BF30%, the more the hardness increased significantly (p < 0.001). The cohesiveness was the highest in WF30%, compared with C and BF30%, the lowest. It was shown significantly different between the C and WF and BF sample groups (p < 0.01). Springiness was the highest in WF10% and WF50%, compared with that in C and BF100%, which were the lowest. Springiness decreased significantly (p < 0.001) ad-ded portion increased between WF30% and BF30%. Gumminess was the highest in BF100% and WF100%, whereas that of WF20% was the lowest (p < 0.001). Chew-iness was the highest in BF100% and WF100% (p < 0.001).

• Journal of the Korean Society of Food Culture
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• v.11 no.4
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• pp.497-506
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• 1996

Fermentation characteristics and quality changes of the typical Korean traditional alcoholic beverages (Kwahaju, Sokokju, Baikhaju, Samhaeju and Hosanchun) were investigated during fermentation and after aging, respectively. They were prepared by their own brewing methods with respect to the same contents of rice and Nuruk (Korean-style bran koji). The consumed total sugar content of the alcoholic beverages (Sokokju, Baikhaju, Samhaeju and Hosanchun) which were brewed with the multiple input steps of seed mash and raw material (ABMIS) was higher than that of the alcoholic beverage (Kwahaju) which was brewed with the single input step (ABSIS). The pH values of all the beverages were similar and were ranged from 3.2 to 3.6. The acidity of ABMIS were lower than that of ABSIS, but alcohol concentration of ABMIS were higher. The fermentation period of the alcoholic beverages with triple input steps was the longest among them. The inner temperature and microbial growth in all the beverages increased at each of input steps of the raw materials. Fusel oil content of ABMIS was lower than that of ABSIS. Major components of the fusel oil were iso-amyl alcohol, iso-butanol, n-propanol, ethyl acetate and acetaldehyde, and its minor components were methanol and n-butanol. The results on quality changes of the alcoholic beverages after aging showed increase of alcohol in ABMIS, but decrease of sugar and acidity. Fusel oil contents of Kwahaju and Samhaeju decreased to be ranged from 3.1% to 13.9% after aging, but those of Sokokju, Baikhaju and Hosanchun increased to be ranged from 10.9% to 23.0%. Sensory evaluation of ABMIS showed better scores than that of ABSIS. It was suggested that the brewing method with multiple input steps of seed mash and raw material was one of the methods to increase fermentation efficiency for brewing the Korean traditional alcoholic beverages.

• Journal of Life Science
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• v.24 no.8
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• pp.865-872
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• 2014

In this study, ethanol and hot water extracts of lees from Korean traditional wine (J-B, J-S, J-Y, J-H, and J-W) were prepared, and their effects on blood coagulation, platelet aggregation, and hemolysis of human red blood cells (hRBCs) were investigated to develop functional food ingredients from lees. The pH and brix of the lees ranged from 3.90 to 4.29 and 5.0 to $27.0^{\circ}$, respectively, and there was a huge difference in the water and ethanol content among the lees. The nuruk and additives used affected the color and physicochemical properties of lees. The J-W takju made from only rice and traditional nuruk, which has $13^{\circ}$ brix and 1.8% of alcohol, has potential as functional food ingredient. With regard to the extraction yields of lees, higher yields were obtained from J-H, which contains different medicinal plants, in ethanol, followed by J-W, J-B, J-S, and J-Y. Higher extraction yields of lees were obtained from J-S in hot water, followed by J-B, J-W, J-H, and J-Y, respectively. The ethanol extract of J-H and the hot water extract of J-Y had the highest contents of total polyphenol and total flavonoids among the lees extracts. The 10 lees extracts did not show hemolysis activity against hRBCs up to 5 mg/ml. In an anticoagulation activity assay, the ethanol extracts of three yakju lees (J-B, J-S, and J-Y) and the hot water extract of J-W inhibited thrombin activity, whereas the hot water extract of J-B, J-S, and J-H inhibited blood coagulation factors. In an antiplatelet aggregation activity assay, only the J-W takju lees showed significant inhibition activity. Our results suggest that lees from traditional wine had high potential as a novel antithrombosis agent.