Enhanced liberation of grape terpenoids
The varietal favour of grapes is mainly determined
by the accumulation and pro®le of volatile secondary
metabolites in V. vinifera [61].
However, a high percentage of these metabolites occur as their
respective, non-volatile O-glycosides.
Several studies have shown that increased enzymatic hydrolysis
of aroma precursors present in grape juice can liberate the aglycone to intensify the varietal character of wines [15].