• Journal of Microbiology and Biotechnology
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• v.30 no.11
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• pp.1739-1749
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• 2020

Exopolysaccharide produced by the yeast Papiliotrema flavescens, isolated from wine grape berries of Champagne vineyard, was investigated for both chemical and functional characterization. SECMALLS and colorimetric assay analyses showed that the EPS is a high M_W heteropolymer (2.37 × 10⁶ g/mol) majorily consisting of mannose, glucose, xylose and glucuronic acid as monosaccharide constituents, with two substituents (sulphate and phosphate groups), and a minor protein moiety. Structural enchainment of these carbohydrates based on methylation, GC-MS and NMR analyses revealed a linear main backbone built up of α-(1 → 3)-D-mannopyranosyl residues on which are branched side chains consisting of a single β-D-glucopyranosyluronic acid residue and β-(1 → 2)-xylopyranoses (2-5 residues). Suggestion of some xylopyranose side chains containing a mannose residue at the nonreducing terminal end was also proposed. This is first report on EPSs from the grape P. flavescens yeast with such structural characteristics. Furthermore, investigations for valuating the application performance of these EPS in relation with their structural features were carried out in 8% alcohol experiment solutions. Very exceptional viscosifying and foaming properties were reported by comparison with commercial biopolymers such as Arabic, gellan and xanthan gums. The intrinsic properties of the natural biopolymer from this wild grape-associated P. flavescens yeast make it a potential candidate for use in various biotechnology applications.

• Korean Journal of Plant Resources
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• v.27 no.6
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• pp.650-659
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• 2014

Large quantities of Korean wild grape (Vitis coignetiae, KWG) pomace, a by-product of grape juice and wine manufacture, are generated annually, and disposal cost of KWG pomace is now increasing. Therefore, this study was conducted to determine total polyphenol, flavonoid, and anthocyanin content in whole KWG, KWG skin and KWG pomace and to identify and quantify flavonoids found in whole KWG and KWG pomace using LC/MS/MS. Spectral analysis showed high total polyphenol and flavonoid in KWG skin extracted with 75% ethanol (p < 0.05). KWG pomace had higher amount of total polyphenol, flavonoid and anthocyanin than whole grape (p < 0.05). Sixteen flavonoids were identified, but only 10 flavonoids were quantifiable from whole KWG and KWG pomace. Both epicatechin and rutin were the major flavonoids, and 521 or 147 ng/g of epicatechin (p < 0.05) and 305 or 110 ng/g of rutin (p > 0.05) were found in whole KWG and KWG pomace, respectively. The results show that KWG pomace is a very rich source of flavonoids, thus KWG pomace can be used as a functional food additive. Plans to include KWG pomace in food production are necessary.

• Korean Journal of Food Science and Technology
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• v.39 no.4
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• pp.390-399
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• 2007

Moru (wild grape), blueberry, bokbunja (blackberry), and blackcurrant were mixed with domestic Campbell Early grapes to improve the quality of domestic wines made from the grape. The color of the Campbell wine was greatly darkened by mixing it with the fruits. The L-value of the wine color during fermentation was lowered from 34 to $6{\sim}13$ by mixing it with 20% bokbunja or blackcurrant. In addition, the a-value of the wine color during fermentation was lowered from 54 to $36{\sim}46$ by mixing it with 20% bokbunja or blackcurrant. The mixing of moru or blueberry also lowered the L- and a-values, but this darkening effect was not higher than that of the Campbell wine that was mixed with bokbunja and black currant. The polyphenol concentration of the wine was greatly increased by mixing it with black currant and bokbunja. The blackcurrant mixed wine had a polyphenol concentration as high as 1.87 mg/mL, whereas the wine made from the Campbell Early grapes alone contained only 1.02 mg/mL of polyphenols after 15 days of fermentation. A sensory evaluation showed that the quality of Campbell wine was the least favorable among different grapes, but its quality was greatly improved by mixing it with bokbunja, black currant, and moru.

• Food Science and Biotechnology
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• v.16 no.2
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• pp.270-274
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• 2007

To characterize the polysaccharides which exist as soluble forms in fruit wines, crude polysaccharides were isolated from red, white, raspberry, wild grape, and pear wine, respectively. Among them, the crude polysaccharide (RW-0) in red wine showed the highest yield and considerable amounts of thiobarbituric acid (TBA)-positive materials. The pectic polysaccharide RW-2 was purified to homogeneity from RW-0 by subsequent size-exclusion chromatography using Sephadex G-75 and its structure was characterized. RW-2 consisted of 14 different monosaccharides which included rarely observed sugars in general polysaccharides, such as 2-O-methyl-fucose, 2-O-methyl-xylose, apiose (Api), 3-C-carboxy-5-deoxy-L-xylose (aceric acid, AceA), 3-deoxy-D-manno-2-octulosonic acid (Kdo), and 3-deoxy-D-lyxo-2-heptulosaric acid (Dha). Methylation analysis indicated that RW-2 comprised at least 20 different glycosyl linkages such as 3,4-linked fucose, 2,3,4-linked rhamnose, 3'-linked apiose, and 2,3,3'-linked apiose, being characteristic in rhamnogalacturonan II (RG-II). High performance size-exclusion chromatography indicated that RW-2 mainly comprised RG-II of higher molecular weight (12,000), and that the changes of molecular weight to apparent 7,000 under less than pH 2.0 were observed. These analyses indicated that the higher molecular weight polysaccharide in RW-2 was mainly present as a RG-II dimer.

• Food Science and Preservation
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• v.30 no.1
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• pp.52-64
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• 2023

100 different yeast colonies were isolated from spontaneously fermented kiwis, persimmons, apples, pears, watermelons, grapes, grape fruits, peachs, and plums, and selected yeast strains were used to produce kiwi-persimmon mixed wine (KPMW). Among the isolates, five representative strains exhibited tolerance to sucrose, alcohol, pH, and potassium metabisulfite when compared with the control yeast strain (Saccharomyces cerevisiae KCCM 12615). All five yeast strains (Y4, Y10, Y28, Y78, and Y81) exhibited 99% 26S rDNA sequence similarity to S. cerevisiae. The pH, acidity, Brix, reducing sugar, alcohol, and organic acid contents were consistent in KPMW prepared from the S. cerevisiae KCCM 12615 and Y28 strains. KPMW made from the Y4, Y10, and Y28 strains exhibited lower quantities of free sugars than those of the KPMW made from the other yeast strains. The level of ethyl esters in KPMW prepared from the Y28 was higher than that in the other KPMWs. All strains, except for Y28, produced lower concentrations of sulfur and ketone compounds. Furthermore, the KPMW produced by the Y28 strains had total phenolic contents with 1.1 g/L, with DPPH and ABTS radical scavenging activities of 57.06% and 55.62%, respectively, and a FRAP assay value of 0.72. Our results suggest that Y28 is a promising yeast strain for producing high-quality wines.

• The Korean Journal of Food And Nutrition
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• v.28 no.4
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• pp.666-675
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• 2015

This study was carried out to develop rose sparkling wine with reed root. To make the base wine with reed root extracts, we first blended wild grape wine with reed root extracts (1:9 v/v) and fermented the mixture for 14 days at $20^{\circ}C$. The pH of the control and the rose base wine with reed root extract (RWE) decreased with increasing fermentation time, but acidity showed the opposite behavior. The control and RWE had $7.33^{\circ}Brix$, and $6.90^{\circ}Brix$, respectively at 14 days, with higher sugar content in the control than in RWE. The alcohol content increased as the fermentation progressed and was higher in RWE than in the control at 14.20% and, 13.83%, respectively. Regarding the color, the lightness decreased as the fermentation progressed. The total polyphenol contents of the control and RWE were 29.19 mg/100 mL and, 34.97 mg/100 mL. The flavonoids decreased as the fermentation progressed. The ABTS radical scavenging activity of the control and RWE were 44.26% and, 64.37% while the DPPH radical scavenging activity showed similar results in the control and RWE. In the second test, we added RWE to base wine, because yeast rearing was inhibited at 14% alcohol content. We made sparkling rose wine with 4 strains and fermented the wine for 8 days at $20^{\circ}C$. The pH of the samples decreased with increasing fermentation time, but the acidity showed the opposite behavior. The $^{\circ}Brix$ decreased and the alcohol content increased with increasing fermentation time. The pressure in sample A was $4.30kgf/cm^2$ at 8 days which was the highest in the samples. In the sensory evaluation, the color, flavor, softness and overall acceptability of the control was higher than the other samples. In conclusion, Saccharomyces cerevisiae Vitilevure Quartz was overall the most suitable rose sparkling wine.

• Korean Journal of Microbiology
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• v.43 no.3
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• pp.217-221
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• 2007

The domestic cultured Campbell's Early and Geubong grapes were fermented far the production of red wines with the isolated wild yeast Saccharomyces cerevisiae IJ850. For the isolation of wild yeast, Geubong and Campbell's Early grapejuices were naturally fermented at room temperature for 6 days without adding stater culture. The strain isolated from Geubong which has 1.8 times higher fermentative ability than the strains isolated Campbell Early was selected. The selected strain was identified by using 26S rDNA sequencing. The strain showed 99.7% of similarity with Saccharomyces cerevisiae and thus identified as Saccharomyces cerevisiae IJ850. It was investigated the fermentative ability as the start culture. For the production of grapewine, the final sugar concentrations of grapejuices were adjusted to the $25^{\circ}Brix$ with anhydrous glucose. The grapejuices were fermented at room temperature for 10 days in the air-locked bottles filled with $CO_2$ gas. The final yield and alcohol concentration of Campbell's Early and Geubong grapewines fermented with the isolated wild yeast were 80.8%, 11.0% and 87.8%, 13.0%, respectively. Between the isolated wild yeast S. cerevisiae IJ850 and the commercial yeast S. cerevisiae EC1118, total acidities of grapewines produced with wild yeast were lower than those produced with the commercial yeast. The pH values and the values of color analysis of grapewines produced with both strains were similar. The total phenol contents of campbell's Early and Geubong wines produced with the isolated yeast and the commercial yeast were obtained in the range of 75 to 125mg/L. In conclusion, S. cerevesiae IJ850 isolated from the domestic cultured Geubong grape is able to use to produce grapewines as stater culture.

• Food Science and Preservation
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• v.18 no.4
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• pp.604-611
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• 2011

Several wild yeasts were isolated from Korean grape varieties before and during spontaneous fermentation. Among them, four strains were isolated based on the alcohol content and flavor production in wine after fermentation of apple juice. In this study, the four yeast strains were identified and characterized. PCR-restriction fragment length polymorphism analysis of ITS I-5.8S-ITS II region with restriction endonuclease Hae III and Hinf I resulted in that all the strains showed a typical pattern of Saccharomyces cerevisiae. Pulse field gel electrophoresis showed three different chromosome patterns with a same band between strains SS89 and SS812. When ITS I-5.8S-ITS II sequences of the four strains were compared with one another, they were similar to those of Saccharomyces cerevisiae CBS 4054 type strain. Identity of the sequences was higher than 97% with those of the type strain. Phylogenetic analysis showed based on the sequences showed they were genetically closed to the type strain. The four identified strains were tested in a medium containing 200 ppm potassium metabisulfite, and the MM10 and WW108 inhibition rates resulted at up to 24 h. The four strains were tested at an incubation temperature of $30^{\circ}C$. The 30% sugar concentration in the medium (w/v) showed the highest growth in 36 h, especially in the case of SS89, which was close to growth 40. The four strains were tested in an 8% ethanol medium (v/v). Alcohol tolerance was initially kept in the incubation process. The strains began to adapt, however, to the exceeded resistance. The four strains showed the lowest inhibition rate at 24 h.