The effects of the level of berry thinning (30% and 50% berry removal) on the quality and sensory properties of Shine Muscat grapes were investigated. As berry thinning increased, the total soluble solids content increased and titratable acidity decreased. Berry thinning increased berry size and cluster weight but caused no change in individual berry weight. Phenolic concentrations as measured by total phenolic, proanthocyanidin, and polymeric tannin concentrations tended to increase with an increase in berry thinning. Gas chromatographic analysis indicated that C6-compounds were the significant constituents of volatile alcohols and aldehydes; linalool was the most abundant monoterpene. Odor activity analysis indicated that (E)-2-hexen-1-ol, (E)-2-hexenal, 1-hexanal, (Z)-3-hexenal, (E)-β-damascenone, linalool, and (E)-linalool oxide were active odorants. Berry thinning increased the accumulation of linalool contributing to high sensory flavor scores in thinned berries. Furthermore, its oxidized derivative-linalool oxide-contributed to enhancing the Muscat flavor. In conclusion, berry thinning induced compositional changes in Shine Muscat grape berries by accelerating the ripening rate, contribution to improved sensory properties.

-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.