• Journal of Microbiology and Biotechnology
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• v.22 no.12
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• pp.1749-1757
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• 2012

Makgeolli is a traditional rice wine favored by the general public in Korea. This study investigated the fermentation and sensory characteristics of using wild yeast strains for brewing makgeolli. A non-Saccharomyces cerevisiae strain was isolated from nuruk and termed Y197-13. It showed 98% similarity to Pichia anomala and had an optimal growth temperature of $25^{\circ}C$. Makgeolli was manufactured using koji, jinju nuruk, and improved nuruk as fermentation agents. Y197-13 makgeolli brewed with koji had alcohol and solids contents of 11.1% and 13.9%, respectively. Sweet sensory characteristics were attributed to residual sugars in makgeolli with 6% alcohol. The makgeolli had a fresh sour taste and carbonated taste. Volatile component analysis showed the isoamyl alcohol, phenylethyl alcohol, isoamyl acetate, and fatty acid, including ethyl oleate and ethyl linoleate, relative peak area was higher in Y197-13 makgeolli than in makgeolli with Saccharomyces cerevisiae. These results suggest the wild yeast, Y197-13, as a candidate for brewing makgeolli.

• Culinary science and hospitality research
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• v.19 no.3
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• pp.46-56
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• 2013

This study investigates the quality characteristics of Sikhye, a Korean traditional drink, made with different amounts of Monascus anka rice, or red yeast rice, and the results are as follows. During the saccharification process of red yeast rice, there was not significant change in pH, and its sugar content increased. It revealed that the optimal hours of saccharification for making Sikhye were four or five hours, which showed the highest in $^{\circ}Brix$. PH decreased significantly with increasing amounts of red yeast rice, and there was no change in sugar content and reducing sugar. Chromaticity L values decreased with increasing amounts of red yeast rice, and a value, b value and the turbidity increased. DPPH free radical scavenging activity of the samples showed significant differences in the samples with high scores as the amounts of red yeast rice increased. As a result of measuring the total microorganism number of the sample stored at $4^{\circ}C$, storability was improved with increasing amounts of red yeast rice. Preference was high in the order of 40%, 50%, 30%, 20%, 0%, and 10%, and the optimal amount of red yeast rice was less than 40-50%. Adding red yeast rice showed high scores in the sensory test, showing red color in Sikhye. In addition, its antioxidative activity effect and microbial growth inhibitory activity were considered to improve storability and preference.

• Preventive Nutrition and Food Science
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• v.16 no.2
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• pp.142-149
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• 2011

The purpose of this study was to elucidate the physicochemical and microbiological properties of Korean traditional rice wine, Makgeolli, supplemented with black garlic extract during fermentation. Black garlic extract was diluted with distilled water to produce 0.5% and 1.0% black garlic solutions. Those solutions were then used to make rice solutions which included 2 kg rice, 40 g Nuruk (a fermentation starter), and 14 g yeast. After being mixed, the rice solutions were fermented for 7 days in a water bath at $28^{\circ}C$. The alcohol contents of the control, 0.5% and 1.0% black garlic Makgeolli were 16.9, 16.0, and 16.2%, respectively. Total acidity, total soluble solids, and color increased throughout the fermentation process. There was an increase of microorganisms throughout the fermentation period in all the samples. Glucose was the highest free sugar, and succinic acid was the highest organic acid detected in all the samples. Thirty nine volatile compounds were detected in black garlic Makgeolli.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.229-235
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• 2016

Korea has a long history of brewing traditional rice wine using a authentic starter culture called nuruk, which contains natural microbial flora. Because rice wine is consumed fresh without filtration, its viable cells contribute to the biological activities of the wine. In numerous studies, microbial strains isolated from rice wine have been screened for their functionalities, which were mainly probiotic properties and antimicrobial activities. Indeed, some lactic acid bacteria (LAB) were confirmed to have strong probiotic activities as well as other health-promoting effects. Moreover, some of the isolated probiotic strains produced functional compounds, such as exopolysaccharides and γ-aminobutyric acid. For antimicrobial activities, some LAB and yeast strains were identified to produce bacteriocins and killer toxins, respectively, with significantly broad spectrum of antimicrobial activity. These functional strains originating from traditional rice wine and their metabolites can be used directly for the production of value-added food products.

• Applied Biological Chemistry
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• v.46 no.4
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• pp.348-352
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• 2003

In this study, strain of high-producing intracellular glutathione was isolated from Korean traditional rice wine. The isolated strain was identified as Saccharomyces cerevisiae based on the morphological, physiological and biochemical characteristics, and was designated as FF-8. The optimal condition for glutathione production by Saccharomyces cerevisiae FF-8 was obtained after cultivation with shaking for 72 hours in the YM medium. The optimal temperature, shaking rate and initial pH for the glutathione production were $30^{\circ}C$, 100 rpm and pH 6.0, respectively. The dry cell weight and glutathione concentration produced by Saccharomyces cerevisiae FF-8 were 5.2 g/l and 72.0 mg/l, respectively, under the optimal culture condition.

• Food Science and Preservation
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• v.8 no.1
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• pp.92-101
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• 2001

In order to develop the Production and application of cholesterol oxidase, a cholesterol degradation bacteria which produces a remarkable amount of extracellular cholesterol oxidase has been isolated from Korea traditional salt fermented flat fish. The isolated strain was identified as a strain of Bacil1us sp. based on its morphological, physiological characteristics and cellular fatty acid compositions. Experiments were carried out to optimize the condition of cholesterol oxidase production using Bacillus sp. SFF34. Bacillus sp. SFF34 was shown to give the maximum yield of cholesterol oxidase in the medium containing 2.0% glucose, 0.5% yeast extract, 0.02% MgSO$_4$$.$7H$_2$O, 0.025% K$_2$HPO$_4$, 0.15% NH$_4$NO$_3$ and 0.2% cholesterol. The optimum culture conditions, temperature, initial pH and agitation speed were 30$^{\circ}C$, 7.0 and 150rpm respectively. The enzyme production reached a maximum level at 24 hrs of cultivation(2.42 U/ml).

• Korean Journal of Environmental Biology
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• v.18 no.1
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• pp.199-203
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• 2000

A bacterium that produce biopolymer was isolated from Gochujang, one of Korean traditional fermented foods, and identified as Bacillus licheniformis. The production of biopolymer was highest and 34mg/250ml, when the baterium was cultivated in condition of sucrose 6.0%, Yeast extract 0.1%, peptone 0.l%, NaCl 3.0%, and pH 6.0. The 1% solution of this biopolymer was able to form a translucent and glossy film. And the solution of biopolymer was found to precipitate Kaolin solution and also stabilize the suspension of lactic acid bacteria within the test range of 0.25-1.00%. [Bacillus licheniformis, Biopolymer].

• Journal of the East Asian Society of Dietary Life
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• v.3 no.2
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• pp.165-173
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• 1993

Jung-Pyun is a traditional steamed rice bread made of fermented rice dough. A series of the Jung-Puyn samples were prepared according to the experimental design of five factors. Factors were fermentation sources(milky rice wine, activated yeast), weight of added water(60, 65, 70, 75% of rice powder), fermentation temperature(30$^{\circ}C$, 40$^{\circ}C$), fermentation times(2,3,4,5,6,12hours) and weight of added baking powder(1, 2% of rice powder). Trained panels judged the steamed rice bread samples to determine the effects of these factors on the sensory characteristics. The results of sensory evaluation revealed that the most preferable steamed rice bread on the overall eating quality was at the 70% adding water and 1% baking powder, 30$^{\circ}C$ for 5 hours incubation made by 1% addition of yeast.

• 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.

• Journal of Life Science
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• v.31 no.2
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• pp.192-198
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• 2021

Red yeast rice has been extensively used as food and traditional medicine for thousands of years in East Asian countries. It is produced by the fermentation of a particular yeast (in general, Monascus purpureus) as rice and various cereals (barley, soybean, etc.). Monascus sp. produces many secondary metabolites during its growth, including pigments, monacolins, and γ-aminobutyric acid. Some metabolites―specifically, monacolin K, γ-aminobutyric acid, dimerumic acid, and monascus pigments―have been reported to lower cholesterol and blood pressure while showing anti-obesity effects. In this study, we investigated the anti-obesity effect of ethanol extract from red yeast barley (RYB) fermented with Monascus sp. BHN-MK 2 on 3T3-L1 cells. The anti-obesity effects of RYB extract were examined: its lipid accumulation inhibitory effect was tested by Oil Red O staining, and obesity-related mRNA expression levels were tested by real-time RT-PCR in MDI stimulated 3T3-L1 cells. The intracellular lipid content of MDI-stimulated 3T3-L1 cells decreased significantly to 5.04%, 12.24%, and 23.52% in response to 200, 400, and 800 ㎍/ml RYB, respectively. Moreovers, we evaluated that RYB extract significantly downregulated the expression of C/EBPα, SREBP-1, and PPAR-γ gene in a dose-dependent manner. As a result, red yeast barley ethanol extracts exerted the strongest anti-obesity effects. Also, the results indicate that red yeast barley could be used as a functional anti-obesity food material.