BIOCHEMICAL CHANGES IN SOME TABLE GRAPE CULTIVARS THROUGHOUT THE RIPENING PROCESS

Abstract

This study was conducted to investigate the biochemical changes observed throughout the ripening process from veraison to harvest periods of 13 table grape cultivars of Vitis vinifera L. species. Present findings revealed that total acidity, total phenolics and total antioxidant capacity of the grape cultivars decreased and water soluble dry matter (WSDM) content, must pH and total anthocyanins increased throughout the ripening process. In harvest period, water soluble dry matter (WSDM) contents varied between 17.0% (‘Trakya İlkeren’ and ‘Şilfoni cultivars’) and 21.6% (‘Kureyş’ cultivar); total acidity values varied between 0.42 g l–1 (Tekirdağ Seedless cultivar) and 1.26 g l–1 (‘Kızılatım’ cultivar); must pH values varied between 2.58 (‘Köhnü’ cultivar) and 3.29 (‘Trakya İlkeren’ cultivar); ripening index values varied between 15.60 (‘Şilfoni’ cultivar) and 41.90 (‘Tekirdağ Seedless’ cultivar); total phenolics varied between 723.5 µg GAE g–1 (‘Mazırım’ cultivar) and 2657 µg GAE g–1 (‘Banazı Karası’ cultivar); total antioxidant capacities varied between 4.27 µmol TE g–1 (‘Mazırım’ cultivar) and 8.21 µmol TE g–1 (‘Köhnü’ cultivar); total anthocyanins varied between 32.3 malvidin-3-o-glikozit µg g–1 (‘Kızılatım’ cultivar) and 205.2 malvidin-3-o-glikozit µg g–1 (‘Banazı Karası’ cultivar). Berry skin colors strongly correlated with total phenolics (R2 = 0.9376) and total antioxidant capacity (R2 = 0.8296).