• Korean Journal of Food Science and Technology
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• v.44 no.2
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• pp.216-223
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• 2012

Dextran was produced by $Leuconostoc$ $mesenteroides$ SM with various contents of yeast extract and its rheological properties were modulated, via an addition of hydroxypropyl methylcellulose (HPMC) of different viscosities. The conversion yield reached 90% after adding 3% yeast extract, which remained constant, thereafter. The acidity of the cultures was approximately 1.4 and 0.9% after fermentation for 24 h at 25 and $30^{\circ}C$, respectively. The total dextran content (107.3 g/kg) was the highest in the presence of the 3% yeast extract. Under the same conditions, the consistency, viscous modulus (G"), and elastic modulus (G') of the cultures were $37.6\;Pa{\cdot}s^n$, 38 Pa, and 50 Pa, respectively. The rheological properties of the culture were changed drastically by the fortification with HPMC of higher concentration and viscosity. The addition of 10% HPMC (4,000 cp) resulted in a significant increase in G" to 1,950 Pa. Furthermore, adding HPMC to a viscous culture resulted in a remarkable increase in both hardness and firmness.

• Applied Biological Chemistry
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• v.16 no.2
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• pp.85-93
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• 1973

These experiments were carried out to study influences of the kind of yeasts and of brewing condition on fermentation of Takjoo mash. The results obtained were as follows: 1. Kind of yeasts and the number of yeasts in mash. When the first stage mash was fermented at $20^{\circ}C$ for $1.5{\sim}2.5$ days and at $25^{\circ}C$, $30^{\circ}C$ for $1{\sim}2days$, in the second stage mash that was fermented at high temperature, the number of yeasts was less as compared with the case of fermentation at low temperature, but the living yeasts number of Takjoo yeast strain Dm-1 was more than those of sake yeast, strain No. 7. 2. Kind of yeasts and composition of ripened mash. 1) In the secondstage mash that was fermented at high temperature($30{\sim}35^{\circ}C$), alcohol percentage of ripened mash using the selected Takjoo yeasts (strains: Dm-1, Y-1) was remarkably higher than the case of another yeasts (strains: No.7, No.6, No. 396, No. 1). 2) Acidity of mash had a little differences between strain Dm-1 and strain No. 7. 3) In the second stage mash that was fermented at high temperature ($30{\sim}35^{\circ}C$), the amount of Formol-N using strain Dm-1 was remarkably less than strain No.7. 3. Brewing condition and alcohol percentage of mash. 1) The fit amount of wheat bran Kuk addition per material was 3 percentage and it was adequate to use the mixture of wheat flour Kuk 20 percentage and wheat bran Kuk 1-2 percentage. 2) Though brewing concentration of the first stage mash was duiluted by twice of general brewing concentration, the yeast reproduction was normal. 3) In addition of wheat flour $80{\sim}140g$ per 180ml water, alcohol percentage of the mash increased almost propotionally according to the increase of the amount of wheat flour. 4) It was recognized that three stage brewing was superior in method to two stage brewing at present.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.426-429
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• 2009

본 연구에서는 바이오에탄올 가격 경쟁력 확보를 위하여 옥수수 및 사탕수수와 같은 식량자원이 아닌 맥주 제조 후 발생되는 폐기물로부터 바이오에탄올을 제조함으로써 기존의 바이오에탄올의 원료로 사용되는 작물의 수급의 불안정 및 곡물가격의 상승에 의한 원료의 가격상승 등에 따른 높은 생산단가에 대한 문제점을 해결할 수 있을 것으로 기대하며, 맥주발효 폐효모액을 이용한 바이오에탄올 제조 특성을 살펴보기 위하여 1일 30톤의 바이오에탄올 제조 공정 해석을 수행하였다.

• The Microorganisms and Industry
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• v.19 no.4
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• pp.37-38
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• 1993

역사적으로 알콜은 인류에게 식품으로써 뿐만 아니라 근래에는 미래의 무공해 대체 에너지로써 많은 기대를 모으고 있다. 식품의 용도로써는 단연 주류를 꼽게 되는데 이 목적으로는 알콜의 발효수율을 올리는 것만이 아니라 소비자의 기호에 맞는 향과 맛등이 중요한 인자로 작용하게 되어 균주 조작에 한계가 있다고 보겠다. 반면 대체 에너지로써의 알콜은 가능한 수단 방법을 다 동원해서 값싸게, 수율높게만 개선하면 되기 때문에 최근 인구에 회자되고 있는 각종 생명공학기법이 광범위하게 사용될 수 있다고 본다. 목적에 따라서 원료는 물론 발효균주도 다양하게 사용되어 지는데 다음에서 용도별로 대표적인 예를 살펴보겠다.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.516-521
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• 1999

The average sugar content and total acidity (tartaric acid %) in Campbell Early harvested at Youngdong, Chungbuk in 1998 were $11{\sim}16^{\circ}Brix\;and\;0.7{\sim}1.1%$, respectively. Extra sugar should be added to musts to have higher than 12% of alcohol content for red wine fermentation. When extra sugar and active dry yeast were added to Campbell Early must, wine fermentation was ended after 9 days at $25^{\circ}C$. The ethanol content was 14.7% (v/v). However, when sugar was added only without yeast, wine fermentation was ended up at 14. 4% (v/v) of ethanol after 15 days. The total acidity (tartaric acid %) and pH was almost unchanged during both fermentations. Potassium metabisulfite was found to inhibit the propagation of bacteria without affecting red wine fermentation. But when potassium metabisulfite was directly added to young red wine after fermentation, the red color of wine was decolorized to yellow.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2004.05a
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• pp.311-313
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• 2004

모짜렐라 치즈 제조 후 부산물로 생산된 유청에 가당을 하고 케휘어 그레인, 포도주 효모를 접종하여 새로운 발효유주 제조공정을 개발하고자 하였다. 그 결과 가당원료로서 물엿을 첨가한 유청 용액의 적정산도가 가장 높게 나타났으며, 첨가한 당의 종류별당 이용율은 배양초기에는 비교적 차이가 큰 편이었지만 배양시간이 경과할수록 차이가 감소하였다. 가당 유청 용액중에서 복합균주의 생육특성은 환원탈지유와는 달리 젖산구균의 생육이 우세하였다. 치즈 유청을 살균 후 당을 첨가하고 케휘어 배양액과 포도주 효모배양액을 접종하여 $20^{\circ}C$의 저온에서 알코올 발효를 실시하였을 때, 배양 1일부터 발포현상이 나타났으며 4일간 배양 후 1.2% 알코올을 함유하는 발효배양액을 얻을 수 있었다. 발효액을 2회에 걸쳐 증류농축기에서 $75^{\circ}C$에서 25분간 감압 하에서 알코올을 추출하여 20% 알코올 원액을 얻을 수 있었다.

• Applied Biological Chemistry
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• v.27 no.4
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• pp.217-224
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• 1984

Effect of a thermophilic yeast (strain T-71) on the ethanol fermentation of raw starchy materials was investigated. The maximum temperature of the thermophilic yeast for the growing and fermentation was a little higher than that of ordinary yeasts and their resistance to ethanol was also high. Even though the optimum temperature of the thermophilic yeast for fermenting ethanol of several raw starchy materials was different depending upon the concentration of mashing, their optimum fermentation temperature was higher than the ordinary yeasts in all cases studied, and their fermentation efficiency was good enough to use. It was also found from the study that the period of fermentation could be shortened for about one to two days by using the thermophilic yeast.

• Applied Biological Chemistry
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• v.39 no.1
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• pp.9-15
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• 1996

To improve the quality of Choungju. a kind of rice wine, two different types of koji were prepared and compared : one from wheat bran with Aspergillus usamii mut. shirousami Y-79 and the other from rice with A. oryzae, and yeast strains from cereal wine mashes were newly isolated and applied for the brewing method. Levels of the related enzymes such as glucoamylase, ${\alpha}-amylase$ and acid protease in the wheat bran koji were higher than those in the rice koji, whereas vice versa in the case of acid carboxypeptidase. An amount of $2{\sim}3%$ wheat bran koji to the weight of total rice was adequate for saccharification of the mash and resulted in improved duality of the fermented mash, accompanied by decrease in koji ordor and amino acidity. When the solution of wheat bran koji and the isolated yeast strains were employed, the better Choungju taste was obtained in comparison with those fermented with Japanese sake yeasts, the strain K-7 and 9, due to the lower content of organic acids especially succinic acid. The amino acidity of the fermented mash was able to be controlled to some extent, when the rico types of koji and the isolated strains were employed, by changing the ratio of the two koji types. However, the application of the rice koji with the isolated strains was not desirable for the brewing process because organic acids were produced in excess and ethanol fermentation was retarded.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.9
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• pp.1467-1474
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• 2013

To develop a starter culture system for the fermentation of mukeunji, we introduced lactic acid bacteria and yeast isolated from mukeunji into kimchi fermentation as a single or a mixed culture. On evaluating mukeunji flavor, we found that the mixed starter kimchi prepared with two strains, ML17 and MY7, gave the best sensory score. These strains were identified as Lactobacillus (Lb.) curvatus ML17 and Saccharomyces (S.) servazzii MY7 by molecular identification method. The fermentative characteristics of starter kimchi were investigated by measuring changes in the physicochemical and microfloral characteristics during the fermentation. The decrease in pH and increase in acidity in the starter kimchi were faster compared to respective values of control kimchi. There was a gradual decrease in hardness of starter kimchi, which was still slow compared to hardness decrease in control kimchi. Microbial analysis of starter kimchi revealed that Lb. curvatus ML17 and S. servazzii MY7 were the dominant organisms during the entire fermentation period. The lactic acid and citric acid contents of starter kimchi were higher than those of the control kimchi after 90 days of fermentation. By sensory evaluation, the starter kimchi scored higher in appearance, mukeunji flavor, sourness, carbonated flavor, savory taste, texture, and overall acceptability, but lower in off-flavor than the control kimchi.

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.1
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• pp.49-55
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• 2001

For the production of probiotic feed enriched with viable yeasts, aerobic liquid culture of Kluyveromyces marxianus was attempted in pulverized residual food wastes. After the preliminary shaking culture result, the liquid food wastes was added with urea($0.5g/{\ell}$), o-phosphate($0.4g/{\ell}$ ), molasses($4g/{\ell}$), and yeast extract($1g/{\ell}$), and the fermentation was carried out in 2-litre jar fermenter. In 12 hours of aerobic mixed culture with Aspersillus oryzae, viable cell count of the yeast reached to the number of $1.4{\times}10^{10}/{\ell}$ in the cultured medium.