鼎湖鳞伞菌胞外多糖在体外3种模拟消化液中的消化作用

Effects of Three Simulated Digestive Juices on in Vitro Digestion of Exopolysaccharide from Pholiota dinghuensis Bi

从鼎湖鳞伞菌发酵液中提取、纯化得到胞外多糖(Pholiota dinghuensis Bi exopolysaccharides,PDEPS)-1,采用体外模拟唾液、胃液、胃肠液模型与分析还原糖含量、分子质量变化及游离单糖含量,探讨了PDEPS-1在体外模拟消化液中的变化。结果表明:PDEPS-1的中性糖含量为97.97%,含少量蛋白、糖醛酸及硫酸基,不含还原糖,分子质量为17.95 k D,由甘露糖及半乳糖组成,物质的量比为53.32∶6.43。PDEPS-1在唾液中不被消化,分子质量不变,没有还原糖及单糖的生成;在模拟胃液及胃肠液中有还原糖产生,但没有检测到单糖。因此,PDEPS-1在体外模拟的3种消化液中具有一定的耐消化性。

Pholiota dinghuensis Bi exopolysaccharides（PDEPS-1） was prepared from the fermentation broth of Pholiota dinghuensis Bi through extraction and purification procedures. The changes of PDEPS-1 in simulated digestive juices were investigated by determining the reducing sugar content, molecular weight, and monosaccharide composition before and after digestion using simulated saliva, gastric juice and gastrointestinal juice model in vitro. The results showed that the content of neutral sugar in PDEPS-1 was 97.97%, and PDEPS-1 also contained small amounts of protein, uronic acid, and sulfuric radical. No reducing sugar was detected in PDEPS-1. The average molecular weight of PDEPS-1 was estimated to be 17.95 k D. It was composed of mannose and galactose in a molar ratio of 53.32：6.43. After digestion in saliva, the molecular weight of PDEPS-1 remained unchanged and neither reducing sugar nor monosaccharides were detected, indicating that PDEPS-1 could not be digested in saliva. After digestion, reducing sugar was detected in both simulated gastric juice and gastrointestinal juice, but monosaccharides were not detected. Therefore, the exopolysaccharide PDEPS-1 from Pholiota dinghuensis Bi was resistant to the digestive juices.