Consecutive and progressive purification of food-derived natural polysaccharide: Based on material, extraction process and crude polysaccharide

Food-derived natural polysaccharides are attracting increasing attention in fields of food and healthy product, and the purification of polysaccharide is indispensable for the study. Currently, purification process mostly focuses on crude polysaccharide, while the importance of polysaccharide purification in the processes of raw material and polysaccharide extraction are easily ignored. This review aims to develop an understanding and practical suggestions on polysaccharide purification. Numerous methods on polysaccharide purification were summarized, and their advantages and disadvantages have been discussed. Finally, current challenges and perspectives on polysaccharide purification were pointed out. Polysaccharide purification should be emphasized and performed based on three consecutive and progressive stages: polysaccharide in raw material, polysaccharide in crude extract and the crude polysaccharide. Besides, the purification of crude polysaccharide comprises the enrichment of polysaccharide and isolation of fractions having different structural or conformational characteristics. However, how to prepare polysaccharide with high purity in large scale and simultaneously preserving its native structure and bioactivity, remains a demanding and important task for future work.