Green extraction approaches for anthocyanins and polyphenols in grape pomace

Abstract

Vitis vinifera L., commonly known as grapes, is one of the most extensively cultivated crops worldwide, with more than 80% of production dedicated to winemaking. This process generates large amounts of byproducts, including grape pomace (GP), wine lees, and wastewater, which pose environmental and economic challenges. Among these residues, GP is particularly significant as it contains high levels of polyphenols, bioactive compounds with well-established antioxidant and anti-inflammatory properties. In recent years, GP has attracted growing interest as a sustainable source of natural compounds for applications in the food, pharmaceutical, and nutraceutical industries. This work highlights the valorisation of GP by examining its phenolic composition, therapeutic potential, and the innovative extraction technologies developed to recover these compounds. Environmentally friendly methods such as ultrasound-assisted extraction, microwave-assisted extraction, supercritical fluid extraction, and natural deep eutectic solvents are emphasised, alongside advanced analytical techniques for precise characterisation. Furthermore, the biological benefits of GP polyphenols are discussed, with recent findings underscoring their metabolism and the critical role of gut microbiota in modulating their activity. By demonstrating how winemaking residues can be transformed into high-value bioactive agents, this study underscores the importance of sustainable waste management and circular economy practices. GP valorisation not only reduces environmental impact but also contributes to the development of eco-innovative solutions that bridge agriculture, health, and industry.