Unlocking the potential of deep eutectic solvents for sustainable pectin extraction

Pectin is a heterogeneous polysaccharide mainly found in the cell walls of plants. Owing to its unique biological and functional properties, pectin is widely used across various industrial sectors, including the food, pharmaceutical, and cosmetic industries. The conventional method of industrially extracting pectin from plant materials is to use prolonged heating under highly acidic conditions. This process poses several drawbacks, including system corrosion, high energy consumption, and environmental concerns. This review article evaluates the potential application of deep eutectic solvents (DESs) as green alternatives to conventional solvents for pectin extraction, due to their exceptional extraction efficiency, minimal toxicity, low cost, eco-friendliness, and reusability. The classification, synthesis procedures, and physicochemical properties of DESs are reviewed. Additionally, the application of DESs for pectin extraction is discussed, both alone and in combination with other emerging extraction techniques, such as ultrasonic, microwave or high-pressure methods. Finally, the advantages and disadvantages of using DESs for pectin extraction are discussed. DESs has already shown considerable potential for the sustainable extraction of pectin from various plant sources, while preserving its functional attributes. The wide range of substances available for preparing DESs enables their extraction properties to be tailored for particular applications, allowing them to meet the specific needs for pectin extraction. DESs can be used in combination with other emerging extraction technologies to improve its pectin extraction efficiency. Therefore, the optimization of DES-assisted extraction techniques may lead to new sustainable methods for isolating pectin.