Advances in the study of secondary metabolites occurring in grapes and wines

In recent years significant advances have been made in the field of secondary metabolites belonging to the polyphenol group and precursors to varietal aromas. Following research on anthocyanins, flavonoids, flavans and phenolic acids of the benzoic and cinnamic type, hydroxystilbenes were thoroughly investigated because of their pharmacological importance. Their presence in the components of grape skins was first noted in 1980. Varietal aromas have mostly been found in their glycoside form. They are known to belong to the class of terpene alcohols, norisoprenoids and benzenoids, though their role in human metabolism is as yet little known.