Artificial simulated gastrointestinal digestion of four carbohydrates containing beta-d-1 → 4 linkages and new GC-TQ/MS-MS method for characterising released monosaccharides

Summary Four types of carbohydrates, including Dendrobium officinale polysaccharide, Dendrobium aphyllum polysaccharide and β-glucans from yeast and barley, were examined, and their structures were found to mainly contain 1,4-linked-β- d -Glc p . Artificially simulated gastrointestinal digestion was conducted to characterise the changes of molecular weight, reducing sugars and released free monosaccharides by high-performance liquid chromatography, kits and the newly developed gas chromatography (GC)-mass spectrometry (MS)/MS analysis, which indicated that high molecular weight and complex spatial structures contributed to delayed monosaccharide release following exposure to digestive solution. The spatial structures of carbohydrates were changed during gastric digestion, but their primary structures were destroyed during intestinal digestion. Additionally, for the developed 7890A/7000 GC-TQ/MS-MS, the new analytical method was successfully used to analyse very low concentrations of monosaccharides in the simulated gastrointestinal digestive system.