Quality Characteristics, Phenolic Composition and Potential Antioxidant Activities of Some Table Grape Varieties in Highland Viticulture

In recent years, climate change and global warming have become significant factors in viticulture, as in many plant cultivations. High-altitude cultivation affects grapevine physiology and composition, offering alternatives for improved viticulture. The aim of this study was to determine of the phenolic content, antioxidant activities and pomological characteristics of commercial table grape varieties ‘Red Globe’, ‘Autumn Royal’, ‘Victoria’ and local varieties ‘Razakı’ and ‘Tilki Kuyruğu’ and ‘Göde Büzgülü’ that are widely grown on the plateau of Antalya in Turkey. Our results showed that ‘Red Globe’ grape variety was found to be the best among the varieties, recommended for its optimal combination of yield and quality. Additionally, the variety ‘Red Globe’ exhibited the highest syringic acid content. The highest (+)-catechin and (−)-epicatesin contents were found in the variety ‘Autumn Royal’, followed by the variety ‘Razakı’. The variety ‘Victoria’ showed the highest t‑resveratrol value at 5.109 mg 100 g−1. This study marked the first research on phenolic content, anthocyanin content, and antioxidant activities for the varieties ‘Tilki Kuyruğu’ and ‘Göde Büzgülü.’ ‘Tilki Kuyruğu’ displayed the highest total polyphenolic and total antioxidant activities, while ‘Göde Büzgülü’ ranked second with the highest total anthocyanin content value.