Research Progress on the Application of Low Eutectic Solvents in Extraction of Plant Polysaccharides

The traditional organic and inorganic solvents used for polysaccharide extraction generally have long extraction time, large solvent consumption, low extraction efficiency and certain pollution problems, and the exploration of new safe solvents has become a hot issue in polysaccharide extraction. As an emerging green solvent, low eutectic solvent (DES) has a variety of solvent characteristics that traditional organic solvents do not possess, and has been widely used in the field of plant polysaccharide extraction in recent years. In this paper, the composition, main properties, synthesis method and important factors affecting the properties of DES are reviewed, and the progress of the application of DES in the extraction of plant polysaccharides such as tea polysaccharides, herbal polysaccharides and peel pectin are summarized.Compared with traditional water and acid-base extraction, the extraction conditions of DES are relatively mild and the energy consumption is lower. The extracted plant polysaccharides have higher extraction rate and purity, and the biological activity and biocompleteness of polysaccharides are better. The limitations and potentials of DES in plant polysaccharide extraction are further elaborated, aiming to provide ideas and theoretical references for the research related to the extraction of plant polysaccharides by DES.