## 1 Introduction  
Shine Muscat, a diploid table grape variety, was obtained in 1988 in Japan from a cross of Akitsu-21 (a hybrid of Steuben--_V. labruscana_\(\times\) Muscat of Alexandria--_V. vinifera_) and Hakunan (_V. vinifera_) [1]. Shine Muscat has recently gained public attention in Asian countries including Korea and China owing to its excellent sweetness, muscat flavor, crispness, and low sourness [2]. The quality of table grapes can be judged by the size of clusters, uniformity and symmetry of berries, and the characteristic color, flavor, and texture of the variety. Variation in grape quality depends primarily on soil management, irrigation, fertilization, pruning, and climate [3]. In addition, several other treatments, including thinning, defoliation, spraying growth regulators, girdling, and canopy management, affect the quality of grape berries [4; 5; 6; 7].  
Excessive fruit load often reduces grapes' quality, such as weakening vine, poor berry size and color, low sweetness, and delayed ripening. Thinning is a common and simple vineyard practice used to improve berry quality during grape cultivation. Researchers have evaluated the effects of various thinning techniques, including shoot thinning, cluster tipping and thinning, berry thinning, shoot topping, and defoliation on different grape varieties. [PERSON] [6] investigated the effects of cluster tipping on the yield and quality of Uslu (_V. vinifera_ L) and Cardinal (_V. vinifera_ L.) grapes and found that cluster tipping improved the quality of both grape varieties, although yields were not affected. [PERSON] et al. [8] investigated the compositional changes of anthocyanins and proanthocyanints in Refosco del peduncolo rososo (_Vitis vinifera_ L) grapes treated with selective berry thinning and classical cluster thinning. They reported that the thinning treatments increased the total anthocyaninnins concentration while decreasing the high molecular weight proanthocyani-dins, mean degree of polymerization, and percentage of galloylation in grape skin. [PERSON] and [PERSON] [9] investigated the effects of cluster thinning on the yield and grape composition of three different grapevine varieties: Sangiovese, Merlot, and Cabernet Sauvignon. Their study indicated that cluster thinning by 40% was significant and reduced yields in all varieties. As results, the quality of the grapes was improved by increasing the concentrations of total soluble solids, anthocyanins, polyphenols, and total nitrogen and decreasing titratable acidity.  
However, to the best of our knowledge, the effects of berry thinning on the compositional changes of Shine Muscat grapes have hardly been studied. [PERSON] et al. [7] evaluated the effects of the applications of growth regulators and floral cluster thinning on the fruit quality and aroma properties of Shine Muscat grapes, but more in-depth investigations are required. Moreover, there have been no studies on the effects of thinning treatment on the sensory properties of Shine Muscat grapes. The present study assessed the effects of berry thinning on the compositional changes by evaluating total soluble solids content, titratable acidity, berry and cluster size and weight, skin color, phenolic composition and concentrations, volatile aroma compounds, and sensory properties of Shine Muscat grapes.