According to their experiments, water limitation
caused a substantial increase in the skin anthocyanin concentration
and malvidin-3-O-glucoside was mostly affected by water supply. The
irrigation regime and rootstock genotype also affected the total
flavan-3-ol monomers in seed tissue, mainly as a result of variations in
the catechin content. The high concentrations of phenolic compounds
and the variation of these concentrations among different grape
varieties show the importance of the study of winemaking waste as a
source of these compounds.