Grapes are cultivated globally with the total area under vines reaching 7.4 million hectares in 2018, and the global wine market is expected to increase to USD 423 billion by the end of 2023. However, winemaking produces large quantities of by-products/wastes like grape pomace (GP; the residue of pressed grapes), wine lees (WL; the residue accumulating in vessels containing wine after fermentation), and vine shoots (VS; generated during the pruning season in the vineyard). Exploitation of agro-industrial side-streams, wastes, and residues, such as WL, GP, and VS, is an issue of vital importance to global good environmental governance. As WL and GP constitute valuable sources of nutrients and VS are a source of cellulose fibers, their use for novel products with applications in winemaking is of major importance. In the present study, the recent trends in sustainable exploitation of such by-products for application in winemaking are presented. WL consist mainly of ethanol, tartaric acid, and yeast cells, and it is usually used for the recovery of these bioactive compounds and as a nutrient supplement of lactic acid bacteria and yeasts growth. GP has been used for the recovery of phenolic compounds, as a substrate for alcohol production, and as fertilizer in the vineyard. New trends include its use for eliminating unwanted wine compounds (like ochratoxin A and pesticides) and as a sustainable fining agent of wines (in order to modify its sensory features such as astringency, bitterness, and mouthfeel). Finally, VS has been used as biochar and for nanocomposite film production.
Sustainable Exploitation of By-Products of Vitivinicultural Origin in Winemaking