Promising Application of Grape Pomace and Its Agri-Food Valorization: Source of Bioactive Molecules with Beneficial Effects

Grapes, particularly the species Vitis vinifera L., are one of the most widely grown crops in the world. Winemaking processes generate a high amount of residues, which currently pose an environmental and economic sustainability problem for companies in the sector. For this reason, solutions are being explored for the development of new products with high-added value derived from the valorization of these residues. One of the wastes produced by winemaking processes is grape pomace, which chemical composition is promising because it is rich in compounds with high antioxidant activity, such as polyphenols (anthocyanins, flavonols, flavan-3-ols, procyanidins), phenolic acids, resveratrol, and fiber. Commonly grape pomace is used to produce distillates and to extract tartaric acid and coloring substances such as enocyanin. Recently, alternative uses of grape pomace have been adopted, such as the production of extracts with antioxidant properties, fermentation substrates, composting and biomass for energy production, and fiber extraction for the development of high-value-added products enriched with bioactive molecules from grape pomace. Here, we discuss how bioactive molecules from grape pomace are involved in various human biological functions and their applications in the agri-food sector.