Effect of ripening stage of grapes on the low molecular weight phenolic compounds of red wines.

摘要

Effects grape harvest date were investigated on levels of individual low mol. wt. phenols that influence wine colour. 2 red grape varieties (Tinto Fino and Cabernet Sauvignon), harvested during 2 consecutive yr at 3 different ripening stages (based on sugar content) were analysed. Wines were monitored during the 18 months of wine ageing, consisting of 12 months in oak barrels and 6 months in bottles. Results showed that the wines made from grapes harvested 1 wk later than the usual date generally had higher contents of some simple phenols, which can act as cofactors that maintain colour intensity and violet tonalities in aged wines. In addition, these wines had lower levels of caftaric and coutaric acids, which are 2 of the main substrates for oxidation and browning processes.