Structural and functional properties of polysaccharides extracted from three Dioscorea species

Dioscorea has a history spanning over 2000 years for both medicinal and edible purposes in China. It contains rich polysaccharides, which are frequently utilized as thickening and stabilizing agents in the food industry. However, there has been relatively little focus on polysaccharides from common Dioscorea species besides D. opposita, such as D. alata and D. esculenta. In this study, non-starch crude polysaccharides were isolated from D. opposita (BD), D. alata (WC), and D. esculenta (GZ). Their structures, physicochemical compositions, and functional properties were characterized and compared. The results indicated three polysaccharides all exhibited characteristic peaks of polysaccharides and possessed triple-helix structures. The Glc (36.78-83.90 %), Man (6.71-26.68 %), and GalA (8.54-10.22 %) were identified as the primary monosaccharide components. In terms of functionality, three polysaccharide solutions demonstrated non-Newtonian flow characteristics and displayed commendable thermal stability. It is worth noting that the antioxidant and emulsifying properties of polysaccharides isolated from D. opposita (BD) and D. alata (WC) were superior to those of D. esculenta (GZ), making them more suitable for use as antioxidants and stabilizers. By comparing polysaccharides derived from different Dioscorea species, this study provides valuable insights into the food, cosmetic, and pharmaceutical industries based on the unique properties of these different polysaccharides.