Research progress on the extraction and purification of plant polysaccharides: a review

Plant polysaccharides have attracted considerable interest in natural product research due to their immunomodulatory, antitumor, and hypoglycemic activities. The development of efficient and gentle extraction and purification techniques is crucial for obtaining highly pure bioactive polysaccharides. This review systematically covers recent progress in extraction methods, including conventional hot water (simple but time‑consuming), acid/alkali (high yield but structure‑damaging), enzyme‑assisted, and physical field‑assisted techniques such as ultrasound and microwave, which provide higher efficiency under gentler conditions. For purification, a comparative analysis was conducted on the advantages and limitations of physical/chemical and biological methods for purifying polysaccharides. Furthermore, the review addresses current challenges, such as limited selectivity and throughput, and explores future directions, including the adoption of green solvents, intelligent process control, and integrated extraction-purification-evaluation platforms, with the objective of facilitating standardized production and high-value utilization.