Preharvest Methyl Jasmonate and Postharvest UVC Treatments: Increasing Stilbenes in Wine

Abstract

In varieties of Vitis vinifera, a number of different stilbenes are present in several parts of the grapevine as constitutive compounds of the lignified organs (roots, canes, seeds, and stems) and as induced substances (in leaves and berries) acting as phytoalexins in the mechanisms of grape resistance against pathogens. This chapter describes the strategies and recent advances regarding ways to increase the stilbene concentration in grapes through the use of a combination of elicitors. Special attention is paid to the treatment combining MEJA (methyl jasmonate)+UVC (Ultraviolet C light), which results in grapes enriched in stilbenes. The effectiveness of treatments is subject to many vinicultural factors, as is the transfer of stilbene compounds into the wine. Maximum skin contact with the must and minimum amounts of fining agent is recommended. However, the production of stilbene-enriched wines is a complex process which is difficult to standardize.