This study was investigated to elucidate the changes in volatile compounds of grapes of the 'Doonuri' that occurred during the ripening and that found in wine made from these grapes. Volatile compounds were extracted by simultaneous steam distillation and were subjected to gas chromatography-mass spectrometry. Ten alcohols, 8 aldehydes, 14 esters, 7 ketones and lactones, and 3 other odor-active compounds were identified in grapes during ripening of berries and in wine. Alcohol compounds were detected at high concentrations than other compounds in wine. The concentrations of aldehydes were highest at initial stage of berry development, but was not detectable in wine. Ester, ketone, and lactone compounds were appeared primarily after veraison and were consistently increased till harvest period. Ester, ketone, and lactone compounds in wine had higher odor activity values than other compounds. The flavor of the 'Doonuri' grapes and wine was primarily developed from ester, ketone, and lactone compounds and unusual aroma like slightly dried peppery and tobacco leaf.

Hunter value (L*, a*, b*) is a rapid and convenience method for compare with different skin color, but not suitable to compare quality with various grape cultivars. Color Index for Red Grapes (CIRG) is one of a simply convert method for grape skin color as numeric data, and many previously result showed that high correlation between CIRG index and various quality factors of grape. In this experiment, we measured CIRG index, total soluble solids (TSS), titratable acidity (TA), and total anthocyanin content on the grapes (Campbell Early, Heukbosuk, Kyoho) from the varaison to harvest. As a result, CIRG index and anthocyanin contents have an exponential correlation; r-square is each 0.8595 in the 'Campbell Early' and 0.8500 in 'Heukbosuk'. And TSS and CIRG index have a positive r-square, at the Campbell Early is 0.7758 and Heukbosuk is 0.7253. Also TA and CIRG index have a positive r-square, at the Campbell Early is 0.7279 and Heukbosuk is 0.6630. These results were shown that CIRG index is a reliable indicator for a none-destructive evaluation of the grape quality.

This study investigated the phenolic compounds of must and wine supplemented with different concentrations (0% (no added stems), 1%, 2%, 3%, and 5%) of fruit stems during winemaking using Muscat Bailey A (MBA) grapes. The red color, and total anthocyanin, total polyphenol, and tannin contents of the must and wine significantly (p<0.05) increased with increasing added amounts of grape fruit stems, while the volatile acid content decreased with increasing added amounts of grape fruit stems. Catechin (8.16∼23.08 mg/L), gallic acid (2.32∼3.28 mg/L), trans-resveratrol (1.38∼3.27 mg/L), and ferulic acid (1.51∼1.59 mg/L) were detected in the must and wine via HPLC. The bioactive substance contents increased with increasing added amounts of grape fruit stems, except for ferulic acid. The DPPH IC 50 activity was higher in the wine (12 mg/L) with 5% grape fruit stems than in ascorbic acid (67 mg/L). These results suggest that the fruit stems of MBA grapes can be used as functional materials for winemaking.

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-The experiment were carried out in 7-year-old 'Campbell Early' grape to increase work efficiency by fruit cluster thinning methods (Pedicel and berry thinning). Pedicel thinning, such as labor-saving cluster thinning of grape, was 6.7 fold higher than the berry thinning for work efficiency. The fruit cluster weight and number of berry were lower in the fruit cluster thinning fruits than in the none-fruit cluster thinning, however, the soluble solid content (SSC) was high and titratable acidity (TA) was low in the fruit cluster thinning fruits than in the none-fruit cluster thinning fruits. Therefore, the bruising rate of berries was decreased in the fruit cluster thinning fruits. Quality uniformity by fruit cluster thinning was proper in fruit cluster weight of 350~450 g when SSC and TA in part of lower, middle and upper of cluster was considered.