Interrelationships of Sugars, Anthocyanins, Total Phenols and Dry Weight in the Skin of Grape Berries during Ripening

This is the authors' abstract. We don't add key points for this paper.

The relationship between levels of anthocyanins, total phenols and sugars in the skin of ripening grapes (Vitis vinifera cvs. Shiraz and Cabernet Sauvignon) was studied in the fruit during the period from véraison to maturity. In grapes with a wide range of anthocyanin contents per unit area of skin there was a good correlation between sugar content of the skin and levels of phenolic substances. The closest correlations, e.g. sugar vs. anthocyanin (r = 0.96) and sugar vs. total phenols (r = 0.95), were found in the first five weeks after véraison. There was a poor correlation between berry Brix levels and levels of polyphenolic substances in the skin at all stages of ripening (r = 0.44-0.45). The role of sugars in the regulation of phenolic biosynthesis in ripening grapes is discussed.