• Journal of Microbiology and Biotechnology
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• v.16 no.12
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• pp.1961-1967
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• 2006

Levels of ethyl carbamate, a potential carcinogen produced naturally during fermentation, in major Korean fermented foods and alcoholic beverages were determined by GC/MS/SIM, and their average daily intake and excess cancer risk in Korean people were estimated. In GC/MS/SIM analysis n.d.-4.26, 1.40-58.90, n.d.-3.76, n.d.-1.87, and 0.40-10.07 $\mu$g/kg of ethyl carbamate were detected in kimchi, soy sauces, fermented pastes, fermented dairy products, and alcoholic beverages, respectively. The average daily intake of ethyl carbamate and excess cancer risk through major Korean fermented foods and alcoholic beverage consumption were 6.0 ng/kg bw/day and $3.0\times10^{-7}$, respectively for the average Korean person aged 3-64 years, and were mainly contributed by Chinese cabbage kimchi, soy sauces, and Soju.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.5
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• pp.598-604
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• 2008

This study was carried out to develop a new traditional alcoholic beverage by using lily scale in order to utilize lily scale as a new matter for nutritious foods. The condition of alcohol fermentation was investigated by the addition of 2.5, 5.0, 7.5, 10.0, 12.5 and 15.0% dried lily scale and 10, 20, 30, 40 and 50% raw lily scale into mash, respectively. The maximum amount of ethanol was produced when 15% dried lily scale and 20% raw lily scale were added to cooked rice at $25^{\circ}C$ for 10 days. In overall acceptability of sensory evaluation, the LSD-5 alcoholic beverage (added 5% dried lily scale into mash) and LSR-20 alcoholic beverage (added 20% raw lily scale into mash) showed the best acceptability. Physiological functionalities of LSD-5 and LSR-20 alcoholic beverage were investigated. Electron donating ability by DPPH solution ($16.5{\sim}23.2%$), SOD-like activity ($20.4{\sim}24.7%$), ACE inhibitory activity ($24.7%{\sim}78.2%$) and tyrosinase inhibitory activity ($57.4{\sim}62.6%$) of LSD-5 and LSR-20 alcoholic beverage were better than the control (non-added liquor). Moreover, acceptability and physiological functionalities of LSD-5 alcoholic beverage are better than LSR-20.

• Korean Journal of Food Science and Technology
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• v.35 no.1
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• pp.103-110
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• 2003

Stable production of fermented kanjang containing 1.8% (v/v) ethanol was obtained within four days using traditional kanjang containing 4% added glucose in packed-bed bioreactor systems filled with immobilized Zygosaccharomyces rouxii and Candida versatilis on porous alumina ceramic bead carrier at $28{\pm}0.5^{\circ}C$ and aeration rate of 0.05 vvm. Specific rates of alcohol production for Z. rouxii and C. versatilis were 0.0033 and 0.0031/day, respectively, and those of glucose consumption were both -0.0087/day in the batch type of alcoholic fermentation. In semi-continuous alcoholic fermentation at a dilution rate of 0.25/day, specific rates of alcohol production for Z. rouxii and C. versatilis were 0.0045 and 0.0029/day, and those of glucose consumption were -0.01 and -0.008/day, respectively, using identical bioreactor system. Similar specific rates of alcohol production were observed both in the batch or semi-continuous process and in the continuous one at the dilution rate of 0.25/day. Sensory characteristics of all alcoholic-fermented kanjang by Z. rouxii, C. versatilis, and a mixture of both yeasts (2:1, w/w) were shown to be significantly superior to those of home-made kanjang as revealed through organoleptic evaluation tests (p<0.05).

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.4
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• pp.602-609
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• 2002

Lao-chao is a traditional Chinese fermented rice product with a sweet and fruity flavor, containing high levels of glucose, a little alcohol and milk-clotting characteristics. In order to optimize commercial production of lao-chao, Rhizopus javanicus and Saccharomyces cerevisiae were selected as the mold and yeast starter, respectively. A commercial mixed starter (chiu-yao) was used as control. Fermentation of the experimental combination revealed a sharp drop in pH (to 4.5) on the fourth day, remaining constant thereafter. Content of reducing sugars gradually decreased throughout the entire fermentation period. Of the free amino acids, higher quantities of alanine, leucine, proline, glutamic acid, glutamine and $NH_3$ were noted. For sugars, glucose revealed the highest concentration, while organic acid levels, including those for oxalic, lactic, citric and pyroglutamic acid, increased throughout the fermentation period. Twenty-one compounds were identified by gas chromatography from aroma concentrates of the lao-chao culture filtrate, prepared using the headspace method. For the flavor components, higher quantities of ethanol, fusel oil and ester were determined in both culture filtrates. In regard to the evaluation of yogurt-like product, there were significant differences in alcoholic smell, texture and curd firmness.

• 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 Food And Nutrition
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• v.34 no.6
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• pp.621-630
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• 2021

In this study, we attempted to compare the maceration processes in the white wine made of Muscat of Alexandria grape having different the fermentation· maceration periods. These wine were sampled and analyzed by fermentation periods. The pH of wines ranged from 3.25 to 3.27 and the total acidity of wines ranged from 0.85~0.91% (w/v) on the 12th day of fermentation period. The ethanol concentration in these wines increased during the alcoholic fermentation period, on the other hand, the soluble solid concentrations (°Brix) decreased. The b value (yellowness) of Muscat of Alexandria wine was the highest at 8.31 in C treatment, which is a wine with a long maceration period, and B (7.19) and A (5.27) were significantly decreased as the maceration period was shorter. The total polyphenol and tannin content of wine increased with the period of maceration. Total polyphenol and tannin contents had the highest values (64.20 and 67.11 mg%, respectively) in the C treatment, which is a wine with a long maceration period on the 12th day of fermentation period. The physiological activities of Alexandria wine were highest level in the treatment with a long maceration period. As a result, this study provides useful scientific information that quality characteristics and physiological activities in white wine.

• Microbiology and Biotechnology Letters
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• v.43 no.3
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• pp.227-235
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• 2015

The objective of this study was to improve the quality of Korean rice wine with wild type yeast strains isolated from various traditional Korean fermented foods. Herein the fermentation and sensory characterization of wild yeast, for the purposes of brewing Korean rice wine, was investigated. 12 yeast strains were examined for their ethanol and glucose tolerance. In addition, the pH, soluble solids, acidity, amino acidity, ethanol content, organic acids, and volatile compounds were also studied for the alcoholic beverages made with the wild yeasts. Almost all Saccharomyces genera yeasts were showed to have a tolerance at 10% ethanol, but non-Saccharomyces genera yeasts displayed a low tolerance. The alcoholic beverages fermented by non-Saccharomyces yeasts demonstrated higher levels of soluble solids, titratable acidity, amino acids, and lower ethanol content, when compared with the alcoholic beverages fermented by Saccharomyces genera yeasts. The organic acid content, such as malic acid, acetic acid, and succinic acid, was seen to also be higher. The electronic nose was analyzed, and discriminant function analysis (DFA) was used for discriminating wild yeast strains. The DFA plots indicated a significant separation of Saccharomyces genera and non-Saccharomyces yeast strains. For volatile compounds, ethyl acetate from non-Saccharomyces yeasts, and ethanol from Saccharomyces genera yeast, a high area ratio was observed.

• Korean Journal of Food Science and Technology
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• v.38 no.4
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• pp.543-547
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• 2006

In order to improve wine quality, the selection of yeast strain and of additives in the manufacture of Bokbunja (Rubus coreanus Miq.) wine was investigated. The chemical composition of the edible portions of Bokbunja fruits was 86.5% moisture, 0.2% crude protein, 0.9% crude fat, 6.6% crude fiber, 0.5% ash and $10^{\circ}Brix$ sugar, and was 2.99% fructose, 2.53% glucose and 0.07% sucrose in fruit extract. The predominant organic acids in the fruit were citric acid (14.57 mg/mL) and malic acid (2.24 mg/mL) with smaller amounts of shikimic, pyroglutamic and oxalic acid. During fermentation, citric and malic acid levels decreased, while formic and acetic acid were released. Saccharomyces cerevisiae KCCM 12224 (Sc-24) was more favorable for alcoholic fermentation of Bokbunja and the addition of 200 ppm of potassium metabisulphite to must was more efficient than other $SO_2$ sources with a higher overall acceptability score. Sc-24 increased alcohol production from 9.8 to 14.8% in a sugar concentration dependent manner $(18-28^{\circ}Brix)$. The color value of early stage Bokbunja must was improved by supplementing with Japanese apricot extract, but this did not influence the color value of Bokbunja wine after primary fermentation. The astringent taste of Bokbunja wine was reduced by removing the seed from the fruit. Sugar solution (50%, w/v) was used instead of sugar power to prevent the possibility of undissolved sugar due to insufficient mixing. This substitution did not influence sensory evaluation.

• Applied Biological Chemistry
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• v.49 no.3
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• pp.202-208
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• 2006

Since abnormal fermentation and short storage duration of oriental melon are the main problems causing loss in commercial value, it is necessary to develop a food processing method using uncommercial melon. In this study, we suggested the effective pretreatment and storage conditions of melon as the material for alcoholic beverage production. Abnormally fermented melon had smaller carbohydrate and larger moisture content than normal one, indicating that carbohydrate in normal melon was probably converted to fermented products during fermentation. The sugar content of oriental melon was increased after fruiting and the highest value $(12.4^{\circ}Brix)$ was found at 5 weeks of storage. The maximum storage duration of normal and fermented oriental melons were 25 and 7 days at $4^{\circ}C$, and 8 and 4 days at room temperature, respectively. The oriental melon for fermentation-use could be conserved after slicing for 30 days at $4^{\circ}C$ with the addition of 1.5% citric acid and for one year at $-20^{\circ}C$ with the plastic film sealing, respectively.

• Korean Journal of Microbiology
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• v.11 no.4
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• pp.167-174
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• 1973

This study included two parts of investigation, the microfloral changes during the brewing process with the changes of pH, total acidity, temperature and alcoholic contents, as well as determination of survival times of major enteric pathogens in Takju. 1. Maximum number of Saccharomyces cerevisiae was $4.3{\times}10^7$ per milliliter on the 5th day of fermentation and gradually decreased. Saccharomyces cerevisiae was one of the predominant strains of the fermentation process. The number of Saccharomyces cerevisiae was $4.3{\times}10^6$ per milliliter at the completion of the brewing and human consumption. In a few days after the completion of the brewing. Bacillus subtilis and some species of Staphylococcus spp. began to grow and those organisms were responsible for the spoilage. 2. Maximum pH, during the brewing, was 5.8 on the first day of fermentation and rapidly decreased until 6th day of fermentation at pH 4.3. 3. Maximum alcholic content was 14.5 degree on the 4th day of fermentation, 10.3 degree on the 5th day and this degree was continued during the experimentation. 4. Maximum temperature, during Takju brewing was 34.deg.C on the 3rd day of fermentation and rapidly decreased up to 23.deg.C on the 6th day and this temperature was continued until the brewing process was finished. 5. Maximum total acidity was 0.57 percent on the 4th day of fermentation and gradually decreased by brewing process was completed. 6. Survival time of major enteric pathogenic bacteria in Takju was as follows : Shigella dysenteriae and Escherichia coli were isolated in two hours and 14 hours respectively, but Salmonella typhi, Vibrio parahemolyticus were not isolated even in an hour after the inoculation of those organisms in undiluted Takju. In diluted Takju, Salmonella typhi, Vibrio parahemolyticus were not isolated even in an hour after the inoculation of those organisms in undiluted Takju. In diluted Takju, Salmonella typhi, Shigella dysenteriae, and Escherichia coli were survived for 50-60 hours, but Vibrio cholerae and Vibrio parahemolyticus were not isolated even if treated within one hour.