银耳多糖作为一种具有益生元潜力的多糖，其在发挥作用前必需经过体内的消化与吸收。该研究通过探讨银耳多糖体外模拟消化过程中的物质组成与理化性质的变化来研究其在口腔、胃和肠三个阶段的消化特性。研究表明，三个消化阶段结束后，除质量分数0.5%样品略有增加外，不同浓度的多糖样品中的还原糖含量均未产生显著变化；银耳多糖主要由甘露糖、葡萄糖、半乳糖醛酸、半乳糖、葡萄糖醛酸组成，且在整个消化过程中，均未被消化酶分解而产生新的游离单糖；不同浓度银耳多糖经胃液消化后，低pH值的胃消化环境会引起多糖分子量的降解，其中0.5%浓度样品组在经三个阶段消化后逐渐较低到3.91×103、3.52×103与2.92×103 ku。消化过程中多糖的结构与组成变化主要取决于pH值的变化，与消化液中的消化酶关系不大，其中适宜浓度的多糖溶液可在消化过程中由于其粘度特性而保持更稳定的结构性质。

Tremella polysaccharide, as a polysaccharide with prebiotic potential, must be digested and absorbed in the body before it can function. In this study, the digestive characteristics of Tremella polysaccharide in the three stages of oral cavity, stomach and intestine were studied by examining the changes in material composition and physicochemical properties of Tremella polysaccharide during the in vitro simulated digestion process. The study showed that after the three digestion stages, the reducing sugar contents in the polysaccharide samples at different concentrations didn’t change significantly, except for a slight increase in the 0.5%-sample; Tremella polysaccharide was mainly composed of mannose, glucose, galacturonic acid, galactose and glucuronic acid, and during the entire digestion process, they were not decomposed by digestive enzymes to generate new free monosaccharides; after different concentrations of Tremella polysaccharide were digested by gastric fluid, the molecular weight of polysaccharide was degraded in the low pH gastric digestive environment, among which, the 0.5%-sample group decreased gradually to 3.91×103 ku, 3.52×103 ku and 2.92×103 ku, respectively, after the three stages of digestion. The structural and compositional changes of the polysaccharides during the digestion process mainly depend on the changes of pH value, and have little to do with the digestive enzymes in the digestive juice. The polysaccharide solution at an appropriate concentration can maintain a more stable structural property during the digestion process due to its viscosity characteristics.

广西科技重大专项（桂科AA20302012-3）