• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.2
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• pp.254-260
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• 2012

This study was conduced to ferment high quality wine by using Omija fruit. Dry Omija farmed and dried in the Moonkyung area was used in this study. The Omija was soaked in 10~40 folds of distilled water to extract water-soluble components and the fluid was filtered after soaking for 6 hours at $50^{\circ}C$. Strains of alcoholic yeast were isolated respectively from spoiled Omija extract. Isolated alcoholic yeasts, OM-1 and OM-2, showed a round to ellipsoidal shape and formed white or milky white colonies on a solid YM medium. Two yeasts produced 10.33~11.23% alcohol from Omija extract adjusted to $10^{\circ}Brix$ with sugar. Their abilities to ferment alcohol were higher than those of other yeast strains belonging to Saccharomyces cerevisiae such as KCTC 7296 (standard strain of Korean Biological Resources Center), Makgeolli yeast, or beer yeast. The isolates OM-1 and OM-2 showed similar abilities in alcohol fermentation. However, the wine fermented by OM-2 got a better sensory score especially with color. Growth of OM-2 was significantly accelerated by addition of a 0.1% urea and 0.02% mineral mixture. A vitamin mixture was effective for the growth only when urea was added as well.

• Food Science and Preservation
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• v.8 no.3
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• pp.326-330
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• 2001

The characteristics of used wine yeast strains were as follows, S6U showed low fermentation speed than those of other yeast strains, but this strain fermented completely later. The wine fermented by W-3 was very low contents of total acid, 0.75% and the ones fermented by UCD530 and AC- contained much extract, 3.26 mg/L and 3.22 mg/L respectively. The wine fermented by CEG and CS2 were predominant in yellowness, and EC1118 produced large amount of acetaldehyde, 49.9 mg/L than those of other strains. EC1118 and CY3079 displayed low methylene blue dyeing ratio, below 15%, meaning high alcohol tolerance yeast. UCD530 produced extremely high contents of glycerol, succinate and lactate compared with other strains. These properties revealed that UCD530 was a typical Saccharomyces bayanus species. The main organic acids produced by wine yeasts were pyruvate, lactate, succinate and acetate. The concentration of acetate in experimental wine could be divided into two parts, one group had concentration below 170 mg/L (UCD530, EC1118, AC-, CY3079, W-3), and the other had concentration up to 350 mg/L (S6U, CEG, CS2).

• Microbiology and Biotechnology Letters
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• v.39 no.1
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• pp.43-48
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• 2011

Physicochemical and organoleptic characteristics of Campbell Early red wines made by traditional method were investigated. The pH values of all Campbell Early red wines were ranged 3.0~3.3 during fermentation. The acidity value of Campbell Early red wine made by traditional method was 0.4~0.9%. Sucrose and alcohol contents were 6~7 Brix and 13.2~14.4% at the end of fermentation, respectively. Campbell Early red wine had the high sensory scores for color, aroma, taste, sharpness, after taste, and overall balance. Because Campbell Early red grapes are well fermented due to the rich fermentative sugar content, Campbell Early red wines made by adding EC-1118 yeast were shown to be the most appropriate.

• Culinary science and hospitality research
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• v.17 no.3
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• pp.162-171
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• 2011

This study investigates the physicochemical and organoleptic characteristics of Campbell Early white wines made by a traditional method. The pH values of all Campbell Early white wines were ranged from 3.2 to 3.5 during fermentation. The acidity value of the Campbell Early white wine made by the traditional method was 0.2~0.9%. Sucrose and alcohol contents were 6~7 Brix and 13.2~14.4% respectively at the end of fermentation. Campbell Early white wine had high sensory scores for color, aroma, taste, sharpness, after taste, and overall balance. Since Campbell Early grapes are well fermented due to their rich fermentative sugar content, Campbell Early white wines made by adding K1-V1116 yeast were shown to be the most appropriate.

• The Korean Journal of Food And Nutrition
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• v.26 no.4
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• pp.633-637
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• 2013

There is an increasing consumption of Makgeolli in both domestic and foreign markets due to a high interest in Korean traditional alcoholic beverages. However, currently, a standardized system of manufacturing, storing and circulating Makgeolli is not available. Therefore, manufacturing the constant quality of finished products is hardly achieved due to the uncertified quality index of Makqeolli. In particular, quality changes occur as a result of variable initial load of microorganisms during shelf life. Eight different commercially available brands of Makgeolli were obtained, and their initial concentrations of yeasts were measured. One brand with the highest concentration was chosen, and the variable initial concentrations were prepared at a concentration of $10^6{\sim}10^8$ yeast CFU/ml. These Makgeolli samples were heat-treated at 65, 70, 75 or $80^{\circ}C$. It was shown that temperatures higher than $75^{\circ}C$ were needed in order to pasteurize Makgeolli properly. In addition;it is considered that controlling the microorganisms by a standardized system for the processing analysis would improve the quality of Makgeolli.

• Journal of Radiation Industry
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• v.4 no.4
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• pp.319-323
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• 2010

Recently, Korean traditional raw rice wines (RRW) have received attention because they are a nutritious food with health properties. But the rapid deterioration of fermented RRW is one of the serious problems for brewing and marketing in the world beyond Korea. The goal of this study was to develop a way to enhance the quality and to lengthen the period of circulation of the RRW. A lactic acid bacterium was isolated from RRW. It was identified as Lactobacillus fermentum (98%) based on its biochemical properties, and 16S rRNA sequence. Treatments of RRW with gamma radiation and green tea extracts reduced the bacterial population except for yeasts and Lactobacillus in the RRW. This result suggested that the natural plant extracts and catechin products can be used as an effective natural storage agent.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.1
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• pp.63-69
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• 2011

To characterize the polysaccharides which exist as soluble forms in Korean traditional alcoholic beverages, the polysaccharides were isolated from Korean pear wine and their anti-complementary activities were examined. The main polysaccharide, PW-1 was purified to homogeneity from the crude polysaccharide (PW-0) in pear wine by size exclusion chromatography using Sephadex G-75. Molecular mass of PW-1 was estimated to be 150 kDa and it contained significant proportion of mannose (81.8%) and 5 different minor component sugars such as arabinose (1.2%), galactose (2.7%), glucose (8.5%), galacturonic acid (5.3%) and glucuronic acid (0.5%). These analyses indicated that the main polysaccharide in pear wine was mainly present as a mannan which had originated from the cell walls of fermenting yeasts. On the other hand, PW-1 showed potent anti-complementary activity in a dose-dependent fashion. Identification of C3 activation products by the crossed immunoelectrophoresis using anti-human C3 and anti-complementary activity of PW-1 in $Ca^{++}$-free condition suggested complement activations by PW-1 from Korean pear wine occur via both classical and alternative pathways.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.10
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• pp.1516-1521
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• 2010

This study was conducted to investigate the physicochemical and quality characteristics of alcohol fermentation of tomato. For yeast, Saccharomyces bayanus Lalvin EC-1118 displayed the highest alcohol content (11.8%), whereas titratable acidity and pH did not differ significantly between different yeasts. Alcohol fermentation conducted at higher temperature ($25^{\circ}C$) resulted in higher alcohol content and lower sugar level. The highest alcohol content was produced using 11.4% sucrose and 11.1% fructo-oligosaccharide. These two saccharides were suitable for tomato alcohol fermentation. Lycopene levels were similar regardless of sugar type, and were approximately 4.2 mg%. To improve lycopene content, three types of fruit wine with low-dose lycopene (LDL), medium-dose lycopene (MDL), and high-dose lycopene (HDL) were made. Their alcohol contents were not significantly different (10.0~10.8%). Lycopene contents of LDL, MDL, and HDL wine were 4.25 mg%, 11.40 mg%, and 20.45 mg%, respectively. Therefore, HDL tomato wine should be manufactured.

• Journal of Microbiology and Biotechnology
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• v.20 no.9
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• pp.1314-1321
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• 2010

Sulfur metabolism in S. cerevisiae is well established, but the mechanisms underlying the formation of sulfide remain obscure. Here, we investigated by real-time RT-PCR the dependence of expression levels of MET3, MET5/ECM17, MET10, MET16, and MET17 along with SSU1 on nitrogen availability in two wine yeast strains that produce divergent sulfide profiles. MET3 was the most highly expressed of the genes studied in strain PYCC4072, and SSU1 in strain UCD522. The strains behaved differently according to the sampling times, with UCD522 and PYCC4072 showing the highest expression levels at 120 h and 72 h, respectively. In the presence of 267 mg assimilable N/l, the genes were more highly expressed in strain UCD522 than in PYCC4072. MET5/ECM17 and MET17 were only weakly expressed in both strains under any condition tested. MET10 and SSU1 in both strains, but MET16 only in PYCC4072, were consistently upregulated when sulfide production was inhibited. This study illustrates that strain genotype could be important in determining enzyme activities and therefore the rate of sulfide liberation. This linkage, for some yeast strains, of sulfide production to expression levels of genes associated with sulfate assimilation and sulfur amino acid biosynthesis could be relevant for defining new strategies for the genetic improvement of wine yeasts.

• Food Science and Preservation
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• v.20 no.5
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• pp.744-750
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• 2013

The indigenous Saccharomyces cerevisiae strains S13 and D8 were isolated at the microbial succession stage during spontaneous fermentation of Campbell Early wine as a resistant to potassium metabisulfite and a high sugar concentration. In this study, the fermentation characteristics of Campbell Early wine were investigated and compared with those of S. cerevisiae W-3, an industrial wine yeast. Alcohol production by the two strains was delayed at the initial fermentation stage, but increased fast when the fermentation continued. After the fermentation, the S13 and D8 wines contained 12.6% and 13.2% (v/v) alcohol, respectively, which were significantly higher than the alcohol content of the W-3 wine (12%, v/v). No marked differences were observed in the residual soluble solid content and the pH. However, the S13 and D8 wines showed high levels of total acid content, including malic and lactic acids. Especially, the lactic acid content was 8.9-fold in the S13 wine and six-fold in the D8 wine, compared with that of the W-3 wine. The two strains produced a higher level of acetaldehyde and a lower amount of methanol in the wine than the W-3 strain. The iso-Butanol content was lower in the two indigenous yeast wines with similar levels of n-propanol and iso-amyl alcohol contents than that in the W-3 wine. In the sensory evaluation, the S13 and D8 wines had higher scores for their color, flavor, taste and overall preferences than the W-3 wine. Especially, the S13 and D8 wines had much higher scores than the W-3 wine for flavor and color, respectively.