Evaluation of colour content in grapes originating from south Moravia

The content of total anthocyanins was determined in grapes of nine grapevine (Vitis vinifera L.) varieties belonging to the traditional blue vine varieties grown in south Moravia (Czech Republic) within the period of 2002-2007. Factors of vintage and health condition of grapes were observed. The material balance of the colour substances in grapes was related to the dry matter of skins of berries and that of fresh grapes used as raw material for vinification. The highest content of pigments was found in the variety Neronet (2.15-4.49 g/kg of fresh grapes), which belongs to the so-called Teinturier varieties. Besides the variety Neronet (containing 30.6-73.4 mg/g of dry skin), high contents of total anthocyanins in dry skins were found in the varieties Dornfelder (24.7-59.0 mg/g of dry skin) and Cabernet Moravia (20.1-59.3 mg/g of dry skin). In the long run, the lowest concentrations of pigments were determined in grapes of the varieties Blauer Portugieser (0.51-1.02 g/kg of fresh grapes) and Pinot noir (0.27-0.60 g/kg of fresh grapes). The highest colour capacity was found in grapes harvested in the 2003 and 2006. Contents of anthocyanins were significantly lower (P = 0.001) in damaged grapes. Grapes containing more than 40% of rotten berries revealed in skins and whole grapes only 41% and 55%, respectively, of the colour capacity of the healthy raw material.