Potential of deep eutectic solvents in the extraction of value-added compounds from agro-industrial by-products

Across the world, an enormous amount of agricultural waste is generated in the excess of 2 billion tons. Such waste with diverse characteristics is the good source of bioactive compounds that are extracted without altering their properties through deep eutectic solvents. The deep eutectic solvents are composed of two or three components which are capable of self-association with a melting point lower than that of each individual component which develop the interest as a good alternative to organic solvents. These solvents are becoming greener alternatives for the extraction because of their tailor-made properties like the possibility of the formulation according to specific applications. In this review, we summarize the main contributions of DESs as sustainable benign diluents to extract bioactive components such as polyphenols, proteins, carbohydrates, alkaloids etc. from the agro-industrial by-products. This work also presents the physicochemical properties, factors affecting the extraction process along with safety and environmental effects of DESs.