Anthocyanin profiles of non-V. vinifera genotypes

Anthocyanins are the main compounds responsible for the color of red grapes and wine. They play a key role in determining the quality of grape berries. Today, wild Vitis genotypes represent an important source of genetic resistance to biotic and abiotic stresses. In fact, these genotypes are used in breeding programs with V. vinifera in order to improve V. vinifera cultivars resistance to phylloxera and powdery mildew diseases (Yang et al. 2014). The resulting inter-specific hybrids present diglucoside anthocyanins which are characteristic of wild Vitis genotypes. Since the acceptable limits of diglucoside contained in wine is 15 mg/L (J. A. Considine, E. Frankish 2014), the aim of this work was to study the anthocyanin profiles of 9 wild genotypes collected in four different vintages. Grape skin anthocyanins were analyzed by HPLC-DAD and twenty different anthocyanins were detected and quantified. Diglucoside derivates were not detected in all wild Vitis genotypes. Out of the nine genotypes analyzed one had no diglucoside anthocyanins. In three genotypes less than 5% of the total amount of anthocyanins detected were diglucosides (from 11,6 to 56,9 mg/kg). In the five remaining genotypes more than 50% of the total were found to be diglucosides (from 522,1 to 1829,2 mg/kg). Cluster analysis showed that each genotype had characteristic distributions of anthocyanins consistent between harvest years.