By-products of wine making, grape pomace and seeds, contain large amounts of proanthocyanidins (Gomez-Mejía ´ et al., 2021; Schieber, 2017). Commercial extracts rich in procyanidins have been used in a wide range of application in the beverage industry for clarification, color stabilization, or prevention of oxidative quality losses. Grape seed extracts have also been used to modulate human gut microbiota.