Cause and Fate of Certain C₆ Compounds Formed Enzymatically in Macerated Grape Leaves During Harvest and Wine Fermentation

Abstract

The formation of leaf aldehyde and leaf alcohol, the most abundant volatiles of macerated grape leaves, was investigated in Vitis vinifera leaves and grapes. Several factors were found to influence the quantities formed, including physiological condition of the fruit or leaf and the degree and type of processing. Once formed, the leaf aldehyde was rapidly reduced and then saturated to n-hexanol. These changes were accelerated with increased temperature and the presence of yeast. The amounts of C₆ volatiles found in musts and wine were independent of whether grapes were mechanically harvested or not.