• Journal of Microbiology and Biotechnology
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• v.27 no.5
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• pp.896-908
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• 2017

In this study, a total of 58 different kinds of nuruk (a traditional Korean fermentation starter) were prepared, including 46 kinds of restored nuruk from ancient documents. Each nuruk was evaluated by analysis of its saccharification power, and the enzyme activities of glucoamylase, ${\alpha}$-amylase, ${\beta}$-amylase, protease, and ${\beta}$-glucanase. The range of saccharification power (sp) of the restored nuruk ranged between 85 and 565 sp. The diastatic enzymes, ${\alpha}$-amylase, ${\beta}$-amylase, and glucoamylase, were significantly correlated to the saccharification power value; conversely, ${\beta}$-glucanase and protease did not have a correlative relationship with saccarification power. In addition, their brewing properties on chemical and organoleptic aspects of traditional alcoholic beverage production were compared. Each raw and supplementary material contained in nuruk showed its own unique characteristics on Korean alcoholic beverage brewing. For the first time, in this study, the traditional Korean nuruk types mentioned in ancient documents were restored using modernized production methods, and also characterized based on their brewing properties. Our results could be utilized as a basis for further study of traditional alcoholic beverages and their valuable microorganisms.

• Mycobiology
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• v.42 no.4
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• pp.353-360
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• 2014

Makgeolli is a traditional Korean alcoholic beverage. The flavor of makgeolli is primarily determined by metabolic products such as free sugars, amino acids, organic acids, and aromatic compounds, which are produced during the fermentation of raw materials by molds and yeasts present in nuruk, a Korean fermentation starter. In this study, makgeolli was brewed using the wild yeast strain Saccharomyces cerevisiae Y98-5, and temporal changes in the metabolites during fermentation were analyzed by ultra-high-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry. The resultant data were analyzed by partial least squares-discriminant analysis (PLS-DA). Various metabolites, including amino acids, organic acids, sugar alcohols, small peptides, and nucleosides, were obviously altered by increasing the fermentation period. Changes in these metabolites allowed us to distinguish among makgeolli samples with different fermentation periods (1, 2, 3, 6, 7, and 8 days) on a PLS-DA score plot. In the makgeolli brewed in this study, the amounts of tyrosine ($463.13{\mu}g/mL$) and leucine ($362.77{\mu}g/mL$) were high. Therefore, our results indicate that monitoring the changes in metabolites during makgeolli fermentation might be important for brewing makgeolli with good nutritional quality.

• Mycobiology
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• v.42 no.4
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• pp.361-367
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• 2014

Makgeolli, also known as Takju, is a non-filtered traditional Korean alcoholic beverage that contains various floating matter, including yeast cells, which contributes to its high physiological functionality. In the present study, we assessed the levels of ${\beta}$-glucan and glutathione in various yeast strains isolated from traditional Korean Nuruk and selected a ${\beta}$-glucan- and glutathione-rich yeast strain to add value to Makgeolli by enhancing its physiological functionality through increased levels of these compounds. Yeast ${\beta}$-glucan levels ranged from 6.26% to 32.69% (dry basis) and were strongly species-dependent. Dried Saccharomyces cerevisiae isolated from Nuruk contained $25.53{\mu}g/mg$ glutathione, $0.70{\mu}g/mg$ oxidized glutathione, and $11.69{\mu}g/g$ and $47.85{\mu}g/g$ spermidine and L-ornithine monohydrochloride, respectively. To produce functional Makgeolli, a ${\beta}$-glucan- and glutathione-rich yeast strain was selected in a screening analysis. Makgeolli fermented with the selected yeast strain contained higher ${\beta}$-glucan and glutathione levels than commercial Makgeolli. Using the selected yeast strain to produce Makgeolli with high ${\beta}$-glucan and glutathione content may enable the production of functional Makgeolli.

• Journal of Ginseng Research
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• v.5 no.2
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• pp.148-154
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• 1981

The effect of ginseng extracts and ginseng saponins on alcoholic fermentation and production of higher alcohols in malt wort by Sacch. uvarnm were studied The results otained were as follows. 1. Alcoholic fermentation of the wort contained 1-5% of ginseng extracts was inhibited slightly, but the wort contained 0.1-0.5% of ginseng extracts were same as the control. 2. 0.02-0.2% of saponin stimulated alcoholic fermentation. 3. Higher alcohol contents were decreased when the wort contained 0.1-0.5% of ginseng extracts. 4. Higher alcohol content were increased when the wort contained 0.02-0.2% of ginseng saponin. Iso-amylalcohol content of fermented wort which contained ginseng saponins were higher 18 -35mg/1 than those of control.

• Preventive Nutrition and Food Science
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• v.5 no.1
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• pp.32-36
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• 2000

Prickly pear juice(PPJ) extracted from prickly pear fruit (Opuntia ficus-indica)was used as raw material for the production of alcoholic beverages. Prickly pear juice (PPJ) had 0.88 oBrix of soluble solid, pH 3.96 and 0.14% of total acidity. Alcohol fermentation of 25% PPJ including 22 oBrix of sugar and 1$\times$106 of inoculum was suitable for alcohol fermentation indicating the rapid decrease of sugar content. The 22 oBrix of sugar in PPJ (25%)GJ (50%) mixture was changed to 6.5 oBrix after fermentation at 3$0^{\circ}C$ for 7 days. The alcohol content was 9.2% (w/v). PPJ (70%)/GJ (30%) mixture produced alcoholic beverage with 6.9% alcohol content resulting in the gradual decrease of soluble for 7 days. On the other hand, PPJ (50%)/GJ(50%) mixture carried out completely the alcohol fermentation at 22$^{\circ}C$ for 6 days and enhanced the red color of alcoholic beverages.

• 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 Applied Biological Chemistry
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• v.49 no.4
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• pp.125-130
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• 2006

In order to utilize non-commercial melon as alcoholic beverage material, in this study the optimum fermentation method and manufacture conditions were investigated and thereafter the properties of final product were determined. As for melon wine made with only melon juice, sensorial properties, particularly flavor, were not acceptable as alcoholic beverage. To improve the lack of melon wine, we made mash with cooked rice and Nuruk, and then added melon juice during fermentation. Acceptable sensorial properties were obtained in melon wine when 30% extract juice of oriental melon was added after 4 day of fermentation. The alcoholic beverage added melon juice showed much higher yellowness value than that without melon juice indicating that a clear yellow color similar to melon was actually observed in final product. Adding melon juice led little changes in amount and composition of free sugars, organic acids and amino acids and could improve sensorial properties.

• Journal of Ginseng Research
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• v.5 no.2
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• pp.139-147
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• 1981

The effect of ginseng extract and ginseng saponins on alcoholic fermentation was studied 1. Alcoholic fermentation on gllicose medium at 30$^{\circ}C$. by Saccharomyces coveanus and Saccharomyces uvavum was stimulated when the media contained 5% and 10 % of ginseng extract, respectively. But that of Saccharomyces cerevisiae was inhibites by the addition of 10% of ginseng extract. 2. Saponin did not stimulate the alcoholic fermentation by Saccharomyces uvarum. 3. The yeast cell counts was increased remarkably by addition of ginseng extract while that of ginseng saponins was increased slightly. Dried cell weight of the broth which Contained 5% of ginseng extract was 3 times than that of control.

• Journal of Applied Biological Chemistry
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• v.55 no.3
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• pp.141-148
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• 2012

Recently, concerns about the volatile hazardous compounds including acetaldehyde, methanol, and fusel oils in alcoholic beverages, which cause hangover such as headache and dizziness after consumption, have been raised. The volatile hazardous compounds might also lead to an increased incidence of liver diseases and even cancers with a high consumption of alcoholic beverages. Acetaldehyde is a volatile compound naturally found in alcoholic beverages and used as flavor in many foods. However this is also regarded as possibly being carcinogenic to humans. Furthermore, acetaldehyde with alcoholic consumption is recently classified as Group 1, carcinogenic to humans. On the other hand, methanol is generated from demethoxylation of pectin by pectinolytic enzyme during alcoholic fermentation. Higher alcohols occur naturally in alcoholic beverages as by-products of alcoholic fermentation and are generally regarded as important flavor compounds. In the current study, we reviewed on the health concern, maximum levels, analytical methods, and current levels of hazardous volatile compounds in alcoholic beverages.

• Journal of Nutrition and Health
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• v.13 no.2
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• pp.104-108
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• 1980

The present dissertation intends to examine whether the use of deterirated candies on the market causes the acetic acid fermentation, and upon scrutiny the result is as follows. 1) 0.5% yeast extract as the sourse of nitrogen is added to 25% candy solution; as a result, the condition of alcoholic fermentation of 8.3% alcohol is favorable. 2) 0.5% yeast extract is added to candy solution after alcoholic fermentation; as a result, 0.2% increase of acidity per hour shows an active acetic acid fermentation of final 6.93%. 3) Acetic acid fermentation by the use of deteriorated candy as sugariness material makes possible up to 90% fermentation ratio through submerged aeration process, and shows 0.092% increase of acidity per hour.