Terpenoids and their role in wine flavour: recent advances

The terpenoids are a major class of natural products with a range of functions in plants. In the grape, monoterpenes, sesquiterpenes and C13-norisoprenoids are present either in a free volatile form, or bound to sugars and rendered non-volatile. Of the many terpenoids in grapes, only a relatively small number makes an important contribution to wine aroma. This review summarises new developments in understanding terpenoids, including the monoterpenes linalool, cis-rose oxide, 1,8-cineole and wine lactone; the sesquiterpene rotundone; and the C13-norisoprenoids β-damascenone, β-ionone, 1,1,6-trimethyl-1,2-dihydronaphthalene and (E)-1-(2,3,6-trimethylphenyl)buta-1,3-diene. Their origin, formation and behaviour during winemaking and ageing, and viticultural influences on their concentration, will be discussed, as well as their role in different wine styles.