Polysaccharide is widely distributed in natural resources, and currently attracts scientists' attention for their various bio‐functions including immunomodulatory activity, hypoglycemic activity, hypolipidemic activity, antitumor activity, promoting effects on gastrointestinal function, and so on. The purity and structure characteristics of different polysaccharides greatly restrict the in‐depth study of their bioactivity mechanism. Therefore, this guideline will display the extraction, isolation, purification, and structural characterization of polysaccharides from natural resources. The extraction methods of acid‐soluble polysaccharides, water‐soluble polysaccharides, and alkaline soluble polysaccharides are included. Common purification methods like membrane filtration, alcohol precipitation, and column chromatographic separation are explained in detail. A comprehensive procedure for polysaccharide structural characterization is given from molecular weight and monosaccharide composition study to Fourier transform infrared and nuclear magnetic resonance analysis. Examples are added where necessary to help you better understand this guideline.

Nine dietary fiber recipes with ratios of IDF to SDF from 1 : 9 to 9 : 1 differently affect the gut microbiota and serum metabolites in healthy mice.

The objective of this study was to investigate the feasibility of the mixture of tremella polysaccharide (TP) and citrus pectin (CP) as an emulsifier by evaluating its emulsifying ability/stability. The results showed that the TP:CP ratio of 5:5 (w/w) could effectively act as an emulsifier. CP, owing its lower molecular weight and highly methyl esterification, facilitated the emulsification of oil droplets, thereby promoting the dispersion of droplets. Meanwhile, the presence of TP enhanced the viscosity of emulsion system and increased the electrostatic interactions and steric hindrance, therefore hindering the migration of emulsion droplets, reducing emulsion droplets coalesce, and enhancing emulsion stability. The emulsification and stabilization performances were influenced by the molecular weight, esterified carboxyl groups content, and electric charge of TP and CP, and the potential mechanism involved their impact on the buoyant force of droplet size, viscosity, and steric hindrance of emulsion system. The emulsions stabilized by TP-CP exhibited robust environmental tolerance, but demonstrated sensitivity to Ca²⁺. Conclusively, the study demonstrated the potential application of the mixture of TP and CP as a natural polysaccharide emulsifier.