• Korean Journal of Food Science and Technology
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• v.44 no.3
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• pp.280-286
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• 2012

The aim of this study was to describe the effects of genetic factors on the chemical composition or metabolites of grapes harvested within the same region. Grapes were separated into pulp, skin, and seed, and physicochemical characteristics were compared among seven grape varieties. The sugar concentrations of the grape musts ranged from $15.17-20.93^{\circ}Bx$ with Seibel variety being highest at $20.93^{\circ}Bx$. pH ranges of grape musts were 3.46-4.02 and total acidity was highest with 1.05 in Steuben variety. Tartaric acid content was highest with 146.68, 500.10 mg/L in pulp and skin extract of Merlot variety. Malic acid content was highest in pulp extract of Seibel variety (1127.14 mg/L) and skin extract of Chardonnay variety (1720.06 mg/L). K content was highest with 379.13 and 828.01 mg/L in pulp and skin extract of Chardonnay variety. Ca content was highest in pulp extract of Kyoho variety (6.98 mg/L) and skin extract of Campbell Early variety (12.26 mg/L).

• 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).

• Korean Journal of Food Science and Technology
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• v.30 no.3
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• pp.487-493
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• 1998

This study was attempted to investigate the changes of chemical components by different yeast strains during alcohol fermentation at $12^{\circ}C$. Saccharomyces cerevisiae, Saccharomyces cerevisiae+Schizosaccharomyces pombe, and Schizosaccharomyces pombe were inoculated in the Seibel grape must, respectively. Sch. pombe began to metabolize malic acid after 4 days fermentation actively and utilized approximately 54% of initial malic acid. Ethanol contents of S. cerevisiae, S. cerevisiae+Sch.. pombe and Sch. pombe were 11.5%, 11.2%, and 10.0%, respectively. The fermentability of Sch. pombe was slower than that of S. cerevisiae. The production of sulfite showed a positive linear relationship with the yeast growth (P<0.01). Sensory scores indicated that the wine samples fermented by S. cerevisiae and Sch. pombe were not significantly different in color, odor, after taste and overall acceptability. Especially, the taste of Sch. pombe was significantly better than that of S. cerevisiae (P<0.05).

• Food Science and Biotechnology
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• v.16 no.6
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• pp.884-888
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• 2007

The aim of this study was to analyze the antioxidant properties of different cultivars of grape skin extract in an in vitro system. The extracts were prepared from eight grape cultivars: 'Campbell Early' (CE), 'Kyoho' (K), 'New Kyoho' (NK), 'Muscat of Alexandria' (MOA), 'Seibel' (S), 'Morgen Schow' (MS), 'Gold Finger' (GF), and 'Meru' (M). The total phenolic acid contents were highest in MS and K. Resveratrol content was high in NK (50.88 mg/l g of coat), and quercetin content was significantly higher in K (0.68 mg/l g of coat) than in the other grape species (0.21-0.44 mg/l g of coat). The K and MS grape species, in which total phenol content was comparatively high (K: $24.15\;{\mu}g/mL$, MS: $25.52\;{\mu}g/mL$), also showed a high level of electron donating activity (K, 53%; MS, 59%). The hydrogen radical scavenging activity of M (50.36%) was significantly higher than the other grape species, including the S (50.21%), MS (49.43%), and K (49.06%) cultivars. Antioxidant activity varied depending on grape species, but overall it was highest in the MS and K cultivars.

• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.911-918
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• 2004

Three dry red, four sweet red, and two white wines were prepared with domestic grape varieties: Gerbong (G), Campbell Early (C), Muscat Bailey A (M), Seredan (Sd), Seibel (Sb), and Neo-muscat (N). Sample wines were analyzed for titratable acidity, ethanol, pH, sugar content, color intensity and hue, and total phenolic content. Preferences of color, aroma, and overall acceptability were determined by 97 panelists using 9-point hedonic scale. Sweetness, sourness, astringency levels of developed wines were evaluated using 9-point just-about-right (JAR) scale. Mean overall acceptability score of C (6.49) was highest among dry red wines (p<0.05). Among sweet red wines, mean overall acceptability score of Sd (3.27) was significantly lower than those of other wines (p<0.05). In white wines, overall acceptability score of Sb (5.20) was slightly higher than that of N (4.92). Overall sourness levels in dry red wines were higher than optimum level. Based on the results, should be lowered, and sweetness and sourness levels of white wines need to be adjusted sweetness levels of C, G, and Sd for the production of sweer redwines. C and M varieties were considered to be suitable for Korean red wine production.