• Food Science and Preservation
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• v.21 no.5
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• pp.757-765
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• 2014

Campbell Early grapes were spontaneously fermented with and without sulfiting to investigate the effect of sulfiting on the fermentation characteristics and physicochemical properties of Campbell Early wine. During the fermentation, the increase in the alcohol and the decrease in the soluble solid contents were faster without sulfiting, as was the increase in the yeast viable counts compared to those with sulfiting. However, the final alcohol and soluble solid contents reached similar levels with and without sulfiting. The PCR-RFLP analysis of the yeast in the ITS I-5.8S-ITS II region revealed that the increase in the S. cerevisiae was faster in the initial fermentation stage and reached a slightly higher level in the late stage with sulfiting than without sulfiting. The wine prepared after the fermentation with sulfiting showed higher malic and tartaric acid contents, as well as methanol, acetaldehyde, and n-propanol contents, than the wine prepared without sulfiting. The ethyl acetate content of the wine without sulfiting was 375.5 mg/L, which was 5.3 times higher than that (70.5 mg/L) with sulfiting. In the sensory evaluation, the wine without sulfiting obtained higher scores in flavor and overall preference than that with sulfiting.

• Korean Journal of Food Science and Technology
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• v.39 no.3
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• pp.309-314
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• 2007

The physicochemical and sensory characteristics of rice wine, Yakju, made with different additions of red yeast rice (0, 10, 20, 30, and 40%) were investigated. The pH of the rice wine decreased and the total acidity increased with greater additions of red yeast rice. Furthermore, the total sugar content increased and the alcohol content decreased with increasing amounts of red yeast rice. The color L-value diminished and the color a- and b-values increased with increasing amounts of red yeast rice. Among the volatile flavor compounds, esters, aldehydes, alcohols, and acids were the most important aroma-active compounds identified in the rice wine. The sample with the 10% red yeast rice addition had the highest ester content, which is a primary component in fruit fragrance. The highest overall acceptability values in the sensory test for color, flavor, taste, and overall favorite were 5.10, 5.75, 5.15, 4.65, and 4.50, respectively, with the addition of 10% red yeast rice.

• Korean Journal of Food Science and Technology
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• v.44 no.5
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• pp.648-652
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• 2012

The sensory characteristics of nine commercially distilled soju samples were determined by sensory descriptive analysis. Eight aroma attributes, as well as four flavor/taste attributes, and six mouth-feel related attributes were evaluated by 9 judges. The descriptive data set was initially analyzed for a significant overall product effect by employing a three-way mixed model analysis of variance (judges, samples, and replications) as well as two-way interactions, with judges treated as random. In addition, correlations between mean attribute ratings were calculated, and a principal component analysis (PCA) of the mean attribute ratings employing the covariance matrix was conducted. Based on the PCA, distilled soju samples were primarily separated along the first principal component, which accounted for 66% of the total variance between the samples, with high intensities of 'alcohol taste' and 'alcohol aroma' versus 'yeast aroma'. The second principal component accounted for 14% of the total variance. Soju containing high alcohol showed stronger intensities of 'bitterness', 'alcohol taste', 'alcohol aroma', as well as all mouth-feel attributes.

• Korean Journal of Food Science and Technology
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• v.44 no.5
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• pp.592-599
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• 2012

The effect of additives on the quality of low-salt doenjang was investigated. The amylase activity of the mustard added group decreased during the fermentation period, and the number of yeast and bacteria was also decreased during the fermentation period. The oxidation-reduction potential was low at the later fermentation stages for the mustard and mustard-garlic added groups, and water activity decreased considerably for the alcohol added group. The L-value of alcohol added doenjang decreased with increases in the a-value. The pH was 4.84 in the mustard added group. The reducing sugar content was 10.15% in the alcohol-garlic added group, and the alcohol production was limited by adding mustard. The amino-type and ammonia-type nitrogen were high in garlic and mustard added groups. Alcohol and alcoholgarlic added groups exhibited significantly improved taste and overall acceptability of doenjang.

• Korean Journal of Food Science and Technology
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• v.24 no.4
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• pp.330-334
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• 1992

In order to improve the flavor quality of a soy sauce, hydrolyzed vegetable protein(HVP), it was subjected to ethanol fermentation by Saccharomyces rouxii and the effect of several environmental factors on the alcohol fermentation of S. rouxii in HVP was investigated. The NaCl content of HVP affected significantly on the growth of S. rouxii, showing growth inhibition above the value of 6%(w/v). The growth of S. rouxii was not inhibited by the coloring materials of HVP. The proper initial concentration of glucose for the growth of the yeast was ranged from 15%(w/v) to 25%(w/v). The optimal temperature for the growth and alcohol production was $25^{\circ}C$. The growth increased with the increasing rate of aeration, while alcohol concentration of fermented HVP showed its maximum value of 4.2%(w/v) at the aeration rate of 0.5 vvm.

• Microbiology and Biotechnology Letters
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• v.27 no.1
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• pp.75-79
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• 1999

Various conditions for onion-juice production, and for alcohol and acetic acid fermemtations were investigated to produce a vinegar from onion. In the production of the onion juice, treatments with enzymes such as 0.6% Celluclast 1.5L and 0.2% Viscozyme L increased the yields significantly from 45.0% to 54.5% and 72.5%, respectively. Alcohol and acetic acid fermentations from the onion juice were effectively improved by using the onion juice heated at 80$^{\circ}C$ for 10 minutes, and by adding 0.3% yeast extract, 0.3% $MgSO_4$ and 0.3% $K_3PO_4$ as nutrients to the onion juice. At the optimum condition, 5.8% alcohol was produced after five days of fermentation at $30^{\circ}C$ from the 14 Brix onion juice, which was adjusted by adding sugar. A vinegar with 6.7% acetic acid content was produced after 20 days of fermentation of $30^{\circ}C$ from 4% alcohol that was adjusted by adding onion juice.

• Microbiology and Biotechnology Letters
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• v.27 no.6
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• pp.491-499
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• 1999

A great variety of the volatile metabolic by-products was formed in yeast cell during alcohol fermentation. The seibel grape (Vitis labrasca) which was grown in the Southern Korea used for wines. The objective of this research was to identify the volatile flavor compounds during alcohol fermentation and aging at 12$^{\circ}C$. saccharomyces cerevisiae and Schizosaccharomyces pombe were inoculated and fermented in seibel grape must. The volatile flavor compounds of logarithmic, stationary and death phases were extracted, concentrated and identified by gas chromatography/mass spectrometer (GC/MS). The volatile flavor compounds were determined by a Hewlett-Packard 5890 II Plus GC which was equipped with Supelcowax 10 fused silica capillary column (60m$\times$0.32mm$\times$0.25${\mu}{\textrm}{m}$ film thickness) wall coated with polyethyleneglycerol. The scan detection method allowed the comparison of the spectrum from the chromatogram of volatile flavor compounds to those in data Wileynbs base library. Among the volatile compounds collected by ether-hexane extraction method, the evolution of 20 main compounds, such as 9 esters (ethyl butyrate, isoamyl acetate, ethyl caproate, n-hexyl acetate, ethl caprylate, ethyl caprate, diethy succinate, ethyl hexadecanoate, 2-pheneethyl acetate), 4 alcohols (3-methyl-1-butanol, 1-hexanol, 1-heptanol, benzoethanol), 4 ketones and acids (2-octanone, caproic acid, caprylic acid, capric acid), 2 furan and phenol (2,6-bis(1,1-dimethyl ethyl)phenol, 2,3-dihydrobenzofuran) were observed during alcohol fermentation and aging. The production of the esters during alcohol fermentation with S. cerevisiae was higher than those of Sch. pombe. The sensory scores of the aged wine samples in aroma, taste and overall acceptability were not significantly different(p<0.05).

• Journal of Microbiology and Biotechnology
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• v.20 no.4
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• pp.767-774
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• 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 Microbiology
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• v.30 no.3
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• pp.160-163
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• 1992

Killer toxin from killer yeast fusant FWKS 260 developed by protoplast fusion between the wild killer yeast and alcohol-fermenting yeast was purified by ammonium sulfate fractionation. Amicon PM I0 concentration. Sephadex G-200 and Scphadcx G-75 column chromatography. The purified killer toxin showed a single band by SIX-polyacvlamide gel electrophoresis. The protein part of killer toxin was active site. which was found by treating the proteolytic enzyme such as pronase E and pepsin to killer toxin. The killer toxin was stable at pH 2.0-5.0 and 20$^{\circ}$C. but inactivated with increasing temperature. The molecular weight was determined to be approximately 13.000 according to the results obtained from the SDS-polyacrylamide gel electrophoresis. It was confirmed that the purified killer toxin is glycoprotein by showing a red single band after st'tining with Schiffs reagent.

• Journal of Microbiology and Biotechnology
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• v.20 no.7
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• pp.1121-1127
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• 2010

This study was performed to investigate the effects of adding a dual starter on the chemical and sensory characteristics of red wine made of Campbell Early grape. The yeast starter, Saccharomyces cerevisiae, and lactic acid bacteria (LAB) starter, Oenococcus oeni, were used for inoculation in the winemaking process for alcoholic fermentation and malolactic fermentation (MLF), respectively. After 200 days of incubation, the chemical compositions of yeast/LAB-added wine (YL-wine) were compared with those of no-starter-added wine (control) and yeast-added wine (Y-wine). The results show that no significant differences were observed in pH, total sugar, and alcohol content among the wine samples, but the malic acid content in YL-wine was significantly reduced, and various esters and higher alcohols were synthesized. The sensory test revealed that the addition of dual starters resulted in improved overall acceptability in wine. This study emphasizes the importance of O. oeni in addition to yeast in making Campbell Early wine.