The influence of Cabernet Sauvignon grape maturity on the concentration and extraction of colour and phenolic compounds in wine (original) (raw)

Extended maturation of wine grapes is employed to achieve optimum berry flavour development and phenolic maturity for the desired wine style. While it has been suggested that fruit maturity may also influence the extraction efficiency of colour and mouthfeel compounds from grapes into wine during processing, this has not been thoroughly evaluated. One aim of this research was to determine the impact of grape harvest date on the colour metrics and phenolic compounds in wines made from grapes harvested beyond historic or traditional maturity levels. To investigate this, berry phenolic composition and concentration were measured over two seasons (2008 and 2009) throughout post-veraison maturity of Vitis vinifera L. cv. Cabernet Sauvignon grapes, along with the composition and concentration of colour and phenolics in the wines produced from these grapes. The data did not support the notion of increased extractability of phenolic compounds with grape maturity. However, the relative wine phenolic concentrations themselves might be more commercially relevant than extractability. Based on the 2008 grape and wine phenolic data, concentrations in wine appeared directly related to the grape concentrations. Unfortunately, the trends were not as clear in 2009. Grape malvidin-3-glucoside and polymeric tannin concentrations increased with ripening and the wine concentrations trended similarly. Grape caftaric acid, catechin, epicatechin, and B2 dimer concentrations declined with ripening, and this was reflected in their concentrations in the wine.