Analysis of physicochemical and mechanical quality characteristics of early-maturing table grape varieties

In table grape production, the economic value, which depends on ecological conditions, is closely associated with the ripening period, yield, and the physical and chemical properties of the clusters and berries of the selected varieties. The selection of varieties with superior physicochemical and textural characteristics can mitigate yield losses and prevent price reductions during ripening, harvest, and marketing. In this study, Early Sweet, Prima, and Trakya İlkeren varieties were found to ripen in the first half of June in the Mediterranean region, while Black Magic, Yalova İncisi, Efem, and Spil Karası ripened during the second half, and Victoria ripened in the first half of July. The total soluble solids (TSS) content of all varieties was determined to be 13-14%, with a maturity index of >20 at harvest. The largest cluster and berry sizes were observed in the Victoria and Efem varieties, while the smallest were recorded for Early Sweet. Regarding mechanical and physical properties, berry cracking tolerance was highest in Victoria and Spil Karası (4236 g and 3082 g, respectively) and lowest in Trakya İlkeren and Yalova İncisi (1657 g and 1842 g, respectively). Berry elasticity was highest in Early Sweet and Spil Karası (342.7 g mm⁻¹ and 335.8 g mm⁻¹, respectively) and lowest in Trakya İlkeren and Yalova İncisi (271.3 g mm⁻¹ and 259.6 g mm⁻¹, respectively). The berry removal force was also comparatively high in Victoria and Spil Karası (847.6 g and 782.1 g, respectively). Based on these findings, it is recommended that grape breeding programs prioritize varieties with large clusters, firm and seedless berries, and high TSS levels. Additionally, the Prima and Early Sweet varieties, characterized by their firmer berries, may be particularly suitable for transportation, extended shelf life, and enhanced competitiveness in both local and international markets.