Grape Pomace Valorization: Extraction of Bioactive Compounds and Industrial Applications Within a Circular Economy Framework

Wine production is one of the most important agricultural activities worldwide, and generates significant amounts of organic by-products, particularly grape pomace. Traditionally, this was seen as waste, but currently, this residue has been reanalyzed from the perspective of the principles of the bioeconomy and circular economy, demonstrating its potential as a rich source of bioactive compounds with great potential for valorization. Its heterogeneous composition accumulates a variety of polyphenols, dietary fibers, flavonoids, phenolic acids, and other secondary metabolites that confer important biological properties, including antioxidant, anti-inflammatory, and antimicrobial activities. The chemical composition of grape pomace varies substantially according to variety, winemaking method, and extraction conditions, directly impacting its potential application. Extraction methods have progressed from traditional procedures to more advanced techniques such as ultrasound, supercritical fluids, and natural solvents, enabling the selective separation of high-value compounds. This review provides a comprehensive and critical overview of grape pomace valorization, emphasising its composition, green extraction and current industrial applications. In addition, regulatory frameworks and sustainability strategies supporting the integration of grape pomace into value-added production chains are discussed. Overall, grape pomace valorization supports waste reduction and the production of new functional products that balance economic efficiency and environmental responsibility.