• Korean Journal of Food Science and Technology
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• v.40 no.6
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• pp.633-642
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• 2008

Several domestic new varieties of grapes were utilized for the fermentation of wines, including Cabernet Sauvignon, NY 21576, Canner, SV 18315, Agawan, and Black Bagal red wines, and Naples, Aligote, and Alicante white wines. The oBx values of the grapes ranged between 17 and $20^{\circ}Bx$. Soluble solid content was adjusted to $21^{\circ}Bx$ by adding sugar for all grapes and fermented at $20^{\circ}C$ for 2 weeks. Black Bagal and Cabernet Sauvignon were relatively slower than other grapes with regard to alcohol production rate. The L value of wine made from Agawan and NY 21576 were lower and darker than those of wines prepared from other grapes. Wine made from NY 21576 grapes had a polyphenol concentration of 1.40 mg/mL, which was higher than that of any other wine, whereas wines made from MBA and all white wines evidenced value of only 0.55 mg/mL and 0.15 mg/mL, respectively, after 2 weeks of fermentation. The sensory evaluations demonstrated that the quality of red wines made from NY 21576, Cabernet Sauvignon, Black Bagal, and that of white wines made from Naples grapes were favorable among the different grape variants.

• Food Science and Preservation
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• v.16 no.5
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• pp.714-718
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• 2009

Polyphenols are naturally occurring antioxidants and play many important roles in human health. Grape leaves have not yet been reported to contain the antioxidants. In this study, the physicochemical properties of powders from young grape leaves, obtained after hot-air or vacuum freeze drying, were analyzed. Weight loss rangedfrom 76-80%, but no difference was found between samples prepared by hot-air orvacuum freeze drying. The L-, a-, and b- values of grape powder all fell upon hot-air drying. Quercetin, resveratrol, catechin, and epicatechin were detected in all cultivars. The contents of the four polyphenols were generally higher in powders obtained by vacuum freeze dryingthan in those prepared by hot-air drying, indicating that vacuum freeze drying is better for optimal preservation of polyphenols. None of three polyphenols assayed was found in some cultivars or after certain drying treatments. Based on physiochemical properties, our findings suggest that powders obtained after vacuum freeze drying are optimal for industrial use.

• Korean Journal of Environmental Agriculture
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• v.28 no.4
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• pp.347-355
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• 2009

Grape fruit quality can be deteriorated with leaf chlorosis caused by magnesium (Mg) deficiency during fruit coloring season in several grapevine varieties. The occurrence of leaf chlorosis and soil Mg states for four grapevine varieties (Campbell Early, Muscat bailey A (MBA), Sheridan, and Kyoho) in the vineyards of Gyeongsan and Youngcheon were surveyed. The relationships between leaf chlorosis and fruit qualities were also investigated. Leaf chlorosis was more widely found and the symptom was stronger in Campbell Early in comparison to the other varieties. Sugar content and Hunter values (L, a, b) of grape fruit were significantly lower in the trees of chlorosis when compare to healthy grapevine trees. Soil Mg contents in the vineyards where leaf chlorosis was found were lower than the optimum level for grapevine. Also Mg content in the petioles of chlorosis grapevines was significantly lower than healthy grapevines. Application of Mg through foliar spray and soil fertigation was quite effective in correcting deficiencies of Mg in grapevine. Proper management of soil Mg availability and K/Mg ratio is strongly recommended to prevent Mg deficiency in grapevine.

• Food Science and Preservation
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• v.15 no.6
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• pp.791-795
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• 2008

In order to establish the method to prepare and use the sulfur dioxide gas generating agent in low temperature storage of grape fruits, the $SO_2$ generation capacity from various sulfite compounds was investigated, and the method to regulate $SO_2$ gas generation and to detect the gas was developed. The conidial germination and mycelium growth of Botrytis cinerea which causes gray mold disease during grape fruit storage was completely inhibited at the $SO_2$ gas concentration of 400 ppm and 3200 ppm, respectively. Sodium hydrosulfite generated the most amount of $SO_2$ gas among the investigated 5 different sulfite or bisulfite compounds. By adjusting the number of pinholes on packaging film of the compound or by adding pH adjusting agent, e.g. citric acid or phosphates, it was possible to regulate the amount and duration of $SO_2$ gas generation from the compound. Because malachite green was quantitatively discolored by $SO_2$ gas, the solution or impregnated paper with the compound could be practically utilized as a indicator detecting $SO_2$ gas. Finally, when Muscat Bailey A grape was stored at low temperature with $SO_2$ gas generating agent, the disease incidence was reduced after storage.

• Korean Journal of Food Science and Technology
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• v.52 no.6
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• pp.649-654
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• 2020

This study was conducted to investigate the quality of wine, produced from 11 different grape varieties. Black Sun, CB, Gaeryangmeoru, MW52, MW55, and Narsha with 0.6-0.8% total acids were good for wine. The total acid content of Wangmeoru wine was too high (1.41%). Black Sun, CB, Gaeryangmeoru, MW52, MW55, MBA, WB, and Wangmeoru showed excellent chromaticity (90dE or higher). Total polyphenols, total anthocyanin and tannin, contents were the highest in Gaeryangmeoru, WB, Wangmeoru, and CB and would be advantageous for wine aging. The results of this study deemed Gaeryangmeoru and CB to be suitable for red wine preparation.

• The Korean Journal of Food And Nutrition
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• v.10 no.2
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• pp.254-262
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• 1997

new wild grape(NWG) cultivated in north Kyungki province in Korea, was tested by analyzing the proximate and physicochemical components of fresh fruit, the chemical components and sensory evaluation of wines made from the grape. NWG contained about 10% seed, and about 70% of juice. Total sugar content, total acidity and pH of the fruit juice were 17.50, 1.14 and 3.48%, respectively. Tartaric acid and malic acid contents of the NWG juice were 0.396 and 0.509%, respectively. Ethanol fermentation of the NWG by Saccharomyces cerevisiae Montrachet was rapid. The ethanol content, total acidity and pH of pink wine made from the NWG juice showed 11.88, 0.85 and 3.55%, respectively. Tartaric acid and malic acid contents of pink wine were 0.208 and 0.421%, respectively. Total anthocyanin content(A520) and color intensity(A520+A420) of pink wine were 5.46 and 9.39, showing greatly higher total anthocyanin content and color intensity than those of European red wines. Total phenol contents of NWG wine were 2, 300~3, 800mg/$\ell$. The pink wine made from the fruit juice was better than the red wine in their quality parameters and sensory scores.

• Journal of the East Asian Society of Dietary Life
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• v.26 no.5
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• pp.445-449
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• 2016

In this study, Red pearl (4x) and MBA (2x) were crossed Gangwon-do Agricultural Research and Extension Services in 2000 to compare the brewing characteristics of Cheonghyang, a seedless kind of grape registered in 2009, by maturity. Fruit characteristics of Cheonghyang were examined after the first racking and 300 days after fermentation during aging in manufacturing wine based on maturity categories of being immature, mature, and overmature after harvest between August 25 and 27, 2014. The soluble solid matter content did not differ between the first racking following manufacturing wine and during ripening, and the alcohol content following the first racking was 12.9% for immature ones, 13.0% for mature ones, and 12.7% for overmature ones., The alcohol content decreased by appropriately 1.3% to 1.8% during ripening. The total acidity content was 0.9% for immature ones, 0.8% for mature ones, and 0.5% for overmature ones following the first racking and showed insignificant variations during ripening of 0.8%, 0.7%, and 0.5%, respectively, with wine made from mature ones showing proper acidity. The volatile acid content following the first racking during ripening, showing insignificant variation by maturity; however, it decreased after ripening. The sensory evaluation detected differences in acidity of wine between mature and overmature grapes. There was no difference in sour taste between immature and mature grapes; however, overmature ones had low levels of sour taste. Our results showed that mature wine had the best overall preference.

• Food Science and Preservation
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• v.21 no.6
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• pp.851-858
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• 2014

Muscat Bailey A (MBA) wine was fermented using the indigenous Korean Saccahromyces cerevisiae strains S13 and D8, and the fermentation characteristics were compared with those of S. cerevisiae W-3, an industrial wine yeast. The strains S13 and D8 showed delayed alcohol fermentation compared with the W-3 strain, but the final alcohol contents of the S13 and D8 wines after fermentation were similar to those of the W-3 wine. The S13 wine showed significantly lower malic-acid content than the W-3 wine, but the D8 wine showed a similar level. Both the wines fermented using the S13 and D8 strains showed significantly lower acetaldehyde, methanol, and fusel oil contents, including n-propanol, iso-butyl alcohol, and iso-amyl alcohol, compared to the W-3 wine. Especially, the methanol content was 98.6 mg/L in the S13 wine and 112.0 mg/L in the D8 wine, which were much lower than 192.8 mg/L in the W-3 wine. The S13 wine obtained the highest score in terms of color among the three wines in the sensory evaluation, with lower Hunter's L, a, and b values compared to the W-3 wine.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.5
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• pp.739-745
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• 2011

This study was performed to investigate the enrichment of resveratrol content in harvested grapes using the modulation of cell metabolism with ultra-violet (UV) irradiation. Resveratrol, a phytoalexin, is produced by stilbene synthase (STSY) from malonyl-CoA and ${\rho}$-coumaroyl-CoA. Its biosynthesis has been reported to be induced by UV and other environmental factors. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis showed that STSY Promoter 1 in grapes was very highly expressed by treatment with UV. Grapes were harvested and treated for post-harvest induction of STSY gene expression with UV, and then their resveratrol content was analyzed. UV treatment for 5 minutes provided the best condition for the induction of STSY gene expression. When harvested Gerbong and MBA grapes were treated with a prototype UV radiator, their resveratrol content was enriched upto 5 times compared with untreated grapes. These results suggest that a post-harvest UV treatment can be applied to enrich resveratrol content in grapes and add value to them.

• Food Science and Preservation
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• v.17 no.5
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• pp.625-630
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• 2010

The berry thinning was a useful practice to reduce bunch size and to alter bunch shape for improving fruit quality. The grape cv. 'Muscat Bailey A' bunches were removed to find berry thinning effect on the bunch, in the apical end of the main stem about 4~6 laterals or conventional treatment and then compared a quality of fruit and wine between the treatments. Bunch weights on the different berry thinning treatment were in the range of 300 to 650g and conventional treatment was 550 to 750g. As a result, according to decreased lateral number of bunch in the treatments, total soluble sugar was increased but total acid was decreased. Our results was shown that wine color and taste components such as total anthocyanin, polyphenol and tannin were depended mainly by berry thinning. Also Berry thinning treatments of bunches was ranked higher sensory score than conventional ones.