Green Solvents for the Extraction of High Added-Value Compounds from Agri-food Waste

Abstract

Large amounts of agri-food by-products, non-edible food, and waste are produced throughout the supply chain from the initial production to the final consumption stages. The valorization of this biomass to obtain high value-added compounds has been the focus of extensive research in the last decade. For this purpose, the use of green techniques is essential to reduce the negative impact on the health and the environment. In this review, we discuss the use of green solvents for the valorization of agri-food waste and by-products, and we consider their potential to replace conventional organic solvents in order to provide more environmentally friendly and sustainable processes. The use of supercritical fluids, neoteric (ionic liquids and deep eutectic solvents), bio-based, and supramolecular solvents is critically dicussed. Parameters affecting extraction efficiency are detailed for each type of solvent along with advantages and limitations for application at the industrial scale.