• The Korean Journal of Food And Nutrition
• /
• v.27 no.5
• /
• pp.971-978
• /
• 2014

Investigation of the quality characteristics of Takju brewing mashes prepared with several different yeasts was carried out during the 42-day brewing process, including examination of titratable acidity, amino acid content, sugar contents, alcohol contents, pH, reducing sugar, yeast population, lactic acid bacteria, and sensory evaluation. Fermivin yielded the highest titratable acidity, while la parisienne had the lowest. Fermivin also had the highest value of amino acid content (14.33%), while other yeasts shows period tended to increase over exclude Instaferm and Song chun. The amount of sugars in instaferm ($11.33^{\circ}Bx$) and instaferm red ($10.53^{\circ}Bx$) were higher than those in La parisienne red and Song chun ($9.57^{\circ}Bx$). The alcohol contents of instaferm was the highest value (15.20%) while the alchol content of the other yeasts tended to increase the fementation period. Fermivin had the highest pH at $12^{th}$ day among the yeasts(4.02), Instaferm red had the lowest pH among the yeasts (3.87) while safbrew wb-06 had the highest reducing sugar content(117.60 mg/mL). Instaferm obtained the highest preference in the sensory evaluation for all items.

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

• Applied Biological Chemistry
• /
• v.14 no.2
• /
• pp.121-129
• /
• 1971

During the Brewing of Soy Sauce on an industrial scale, Saccharomyces rouxii $T_9$ was cultured and added to the soy sauce mash. The comparative experiments of soy sauce mash in non-addition and addition group of yeast were examined in this report. The yeast flora and chemical composition of Soy sauce mash through out the brewing were observed and the results obtained were as follows. (1) The number of Osmophilic yeast in one ml of soy sauce mash showed $185{\times}10^3$ 1 month after mashing and $750{\times}10^3$ 4 months after mashing in case of yeast group, while presented as $98{\times}10^3$ 1 month after mashing and $394{\times}10^3$ 4 months after mashing in case of non-yeast group. And the number of Osmphilic yeast in yeast group was twice of that in non-yeast group. (2) The number of ordinary yeast of TTC red group was shown as $2132{\times}10^3\;to\;3252 ×10^3$ 5 to 6 months after mashing in case of yeast group, while presented $752{\times}10^3\;to\;1251{\times}10^3$ in case of non-yeast group. And the yeast group was shown more than non-yeast group in ordinary, red pink and pink yeast number. (3) TTC red yeast were strongly appeared in both addition and non-addition group of yeast from 1 month after mashing to 6 months after mashing. (4) Though total nitrogen, pure extract, pH and buffer action contents of soy sauce showed similiar tendency in yeast and non-yeast group, alcohol and color density contents were highly appeared in yeast group and reducing sugar content was in non-yeast group respectively. (5) By the results of Organic function test of soy sauce mash, the difference of taste quality in yeast and non-yeast group were not evidently appeared, however, the appearance and flavour of the soy sauce were better in yeast group than in non-yeast group.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.12
• /
• pp.340-347
• /
• 2019

This study investigated the brewing properties of rice beer made with yeast isolated from traditional whole wheat nuruk. The experimental method was followed by alcohol fermentation and quality analysis for six months after separating the yeast from nuruk. The yeasts isolated from traditional nuruk showed normal fermentation characteristics, like those of commercial yeast, in terms of alcohol production capability, sugar content, and pH reducing power. Especially, the yeast (KCCM 301) isolated from whole wheat nuruk showed higher contents of glycogen and trehalose than that of commercial yeast, and so KCCM 301 yeast has excellent yeast vitality. Meanwhile, the yeast (KCCM 90301) isolated from traditional Nuruk produced significantly higher alcohol and ester contents than that of commercial yeast. This has a positive effect for supplementing the taste and aroma of rice beer. In conclusion, the yeasts isolated from whole wheat nuruk showed the general alcohol fermentation pattern and aroma content of rice beer. These yeasts seem to be effective in strengthening the flavor of rice beer.

• Proceedings of the Korean Society for Applied Microbiology Conference
• /
• 2004.06a
• /
• pp.156-160
• /
• 2004

• Journal of Microbiology and Biotechnology
• /
• v.20 no.4
• /
• pp.767-774
• /
• 2010

In this study, the problems of high caloric content, increased maturation time, and off-flavors in commercial beer manufacture arising from residual sugar, diacetyl, and acetaldehyde levels were addressed. A recombinant industrial brewing yeast strain (TQ1) was generated from T1 [Lipomyces starkeyi dextranase gene (LSD1) introduced, ${\alpha}$-acetohydroxyacid synthase gene (ILV2) disrupted] by introducing Saccharomyces cerevisiae glucoamylase (SGA1) and a strong promoter (PGK1), while disrupting the gene coding alcohol dehydrogenase (ADH2). The highest glucoamylase activity for TQ1 was 93.26 U/ml compared with host strain T1 (12.36 U/ml) and wild-type industrial yeast strain YSF5 (10.39 U/ml), respectively. European Brewery Convention (EBC) tube fermentation tests comparing the fermentation broths of TQ1 with T1 and YSF5 showed that the real extracts were reduced by 15.79% and 22.47%; the main residual maltotriose concentrations were reduced by 13.75% and 18.82%; the caloric contents were reduced by 27.18 and 35.39 calories per 12 oz. Owing to the disruption of the ADH2 gene in TQ1, the off-flavor acetaldehyde concentrations in the fermentation broth were 9.43% and 13.28%, respectively, lower than that of T1 and YSF5. No heterologous DNA sequences or drug resistance genes were introduced into TQ1. Hence, the gene manipulations in this work properly solved the addressed problems in commercial beer manufacture.

• Korean journal of food and cookery science
• /
• v.32 no.1
• /
• pp.44-49
• /
• 2016

Organic acid fermentation by yeast an important in the flavor and aroma. June 19th brewing each by each of the kinds of yeast (Instaferm, Instaferm red, La parisienne, La parisienne red, Fermivin, Safbrew wb-06, Safele s-04, Song chun) were analyzed organic acid during storage life. All yeast with reduced organic acid on 4 days. On 10 days, Instaferm, Instaferm red, La parisienne, La parisienne red, Fermivin yeast with the increased organic acid but on 19 days these reduced organic acid and maintain to 28 days. However use of Safbrew wb-06, Safele s-04, Song chun yeast the organic acid at storage and maintain organic acid content to 28 days. The variation of each organic acid during storage life characteristic of the yeast.

• Microbiology and Biotechnology Letters
• /
• v.18 no.5
• /
• pp.506-510
• /
• 1990

The Takju brewing of raw rice starch was carried out by the simultaneous saccharification- fermentation using Rhizopus sp. koji and yeast, and compared with the Takju mash brewed by the conventional method. Rhitopus koji was prepared with uncooked rice for Takju brewing without cooking of rice starch. Alcohol concentration of Takju mash brewed with uncooked rice was slightly higher of 1.8% than that with cooked one. Amino acid contents was almost double and fuse1 oil contents was lower in uncooked brewing. The Takju mash prepared after fermentation without cooking of rice had a characteristic odor of raw material and a good quality of taste.

• Mycobiology
• /
• v.41 no.3
• /
• pp.139-144
• /
• 2013

Makgeolli is a traditional cloudy-white Korean rice wine with an alcohol content of 6~7%. The present study investigated the morphological characteristics, carbon-utilizing ability, fatty acid composition, alcohol resistance, glucose tolerance, and flocculence of Saccharomyces cerevisiae Y98-5 and Pichia anomala Y197-13, non-S. cerevisiae isolated from Nuruk, which is used in brewing Makgeolli. Similar morphological characteristics were observed for both isolated wild yeast strains; and the carbon source assimilation of Y197-13 differed from that of other P. anomala strains. Strain Y197-13 was negative for D-trehalose, mannitol, arbutin, I-erythritol, and succinic acid. The major cellular fatty acids of strain Y197-13 included C18:2n6c (33.94%), C18:1n9c (26.97%) and C16:0 (20.57%). Strain Y197-13 was Crabtree-negative, with 60% cell viability at 12% (v/v) ethanol. The flocculation level of strain Y197-13 was 8.38%, resulting in its classification as a non-flocculent yeast.

• Journal of Microbiology and Biotechnology
• /
• v.20 no.11
• /
• pp.1539-1545
• /
• 2010

In beer, glutathione works as the main antioxidant compound, which also correlates with the stability of the beer flavor. In addition, high residual sugars in beer contribute to major nonvolatile components, which are reflected in a high caloric content. Therefore, in this study, the Saccharomyces cerevisiae GSH1 gene encoding glutamylcysteine synthetase and the Saccharomycopsis fibuligera ALP1 gene encoding ${\alpha}$-amylase were coexpressed in industrial brewing yeast strain Y31 targeting the ${\alpha}$-acetolactate synthase (AHAS) gene (ILV2) and alcohol dehydrogenase gene (ADH2), resulting in the new recombinant strain TY3. The glutathione content in the fermentation broth of TY3 increased to 43.83 mg/l as compared with 33.34 mg/l in the fermentation broth of Y31. The recombinant strain showed a high ${\alpha}$-amylase activity and utilized more than 46% of the starch as the sole carbon source after 5 days. European Brewery Convention tube fermentation tests comparing the fermentation broths of TY3 and Y31 showed that the flavor stability index for TY3 was 1.3-fold higher, whereas its residual sugar concentration was 76.8% lower. Owing to the interruption of the ILV2 gene and ADH2 gene, the contents of diacetyl and acetaldehyde as off-flavor compounds were reduced by 56.93% and 31.25%, respectively, when compared with the contents in the Y31 fermentation broth. In addition, since no drug-resistant genes were introduced to the new recombinant strain, it should be more suitable for use in the beer industry, owing to its better flavor stability and other beneficial characteristics.