• The Korean Journal of Food And Nutrition
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• v.33 no.5
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• pp.512-523
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• 2020

The objective of this study was to investigate the quality characteristics of Cheongsoo wine using freeze concentration fermented with 5 kinds of yeast strains (Saccharomyces cerevisiae EJ18, EJ30, HK22, HK32 and Fermivin). We compared the characteristics, volatile flavor component and physiological activity of 5 wines. The freeze concentration can increase the sugar concentration in grape juice by reducing its water content and the alcohol content of freeze-cententrated Cheongsoo wines ranged between 15.0~15.8%. The pH of wines ranged from 2.92 to 2.94 and the total acidity and soluble solid of wines ranged from 12.40~13.27. °Brix. The major organic acid in the wines was tartaric acid (4.49~5.11 mg/mL) and malic acid (7.00~7.97 mg/mL). It contains higher functional compounds in wine fermented with yeast (EJ18, EJ30, HK22, HK32) than wine fermented with fermivin. α-glucosidase and tyrosinase inhibitory activity had the highest values (78.87% and 62.25%) in wine fermented with HK22 and EJ18 yeast, respectively. 16 volatile flavor compounds (alcohols, esters, ketones, acids, and others) were detected in the Cheongsoo wines by freeze concentration. These results provide useful information that the quality characteristics of wine developed by the freeze-concentration method using grapes cultivated in Korea.

• Food Science and Preservation
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• v.20 no.6
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• pp.846-853
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• 2013

We investigated the effect of the cell-wall-degrading enzyme and its skin contact time on the brewing characteristics of Cheongsoo grape. The easy of juice extraction was excellent at the cell-wall-degrading enzyme and skin contact treatments, and the aroma was best after five days of skin contact treatment. Furthermore, the juice yields of the Chengsoo grape were more dramatically increased by the cell-wall-degrading enzyme and skin contact treatments than by the control. The data on the pH, total acidity, and soluble solids did not significantly differ among the treatments, and the pH range from 3.1 to 3.4; the total acidity from 0.5% to 0.6% (as tartaric acid); and the soluble solids, from 6.7 to 7.1 $^{\circ}Brix$. The alcohol content of cell-wall-degrading enzyme treatment was highest with 13.3%. The total polyphenol was gradually increased with the longer skin contact time, and was highest after 10 days of skin contact treatment, at 306.4 mg/L. The main organic acids detected in the Cheongsoo wine were malic and tartaric acid, and citric, succinic and lactic acid were also detected. Our results show that the cell-wall-degrading enzyme and skin contact treatments were better in terms of the easy of juice extraction and significantly increased the juice yield and the volatile compound of the Cheongsoo wine.

• The Korean Journal of Food And Nutrition
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• v.29 no.4
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• pp.538-546
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• 2016

This study was carried out to evaluate the quality characteristics of Korean domestic commercial white wines. Four sample wines were analyzed in terms of their pH, total acidity, volatile acidity, alcohol content, soluble solid, free $SO_2$, total $SO_2$, color, free sugar content, organic acid, volatile compounds, total polyphenol content, DPPH radical scavenging activity and sensory characteristics. The pH of wines ranged from 3.06 to 3.76 and their total acidity from 0.43 to 0.83% (v/v). The alcohol content of samples ranged from 9.4 to 12.8% (v/v) and their soluble solid contents from 9.9 to $12.3^{\circ}Brix$. The free $SO_2$ and total $SO_2$ contents of the W1 wine were lower than those of the other wines, while the color intensity, a (redness) and b (yellowness) of W1 wine were higher than the values of the other wines. The malic acid contents of the four wines indicated that complete malolactic fermentation (MLF) occurred in W1, incomplete MLF in W3, and was absent in W2 and W4. Aroma analysis resulted in identification of 10 alcohols, 11 esters, 2 ketones and 6 miscellaneous compounds. 2,3-Epoxybutane and 1-(ethenyloxy)-pentane levels in were significantly higher W1 than the other wines, while several types of ester predominated in W2, W3 and W4. W1 had the lowest sensory score among the four wines. Therefore, the quality characteristics of domestic white wines are considered to be acceptable.