Sugars and Nutrition 105 Only six sugar molecules are important in human nutrition. These are the monosaccharides glucose, fructose and galactose, and the disaccharides maltose, sucrose and lactose. Yet it still contributes to good health because it prevents a myriad of diseases of the colon. Fiber can be divided into two categories based on solubility. Many enzymes are involved in this process.
Salivary amylase begins to break down starch in the mouth.
The acidity of the stomach stops this process, but the process resumes in the duodenum where pancreatic alpha-amylase is secreted. The two amylases produce maltose and maltotriose from amylose, and maltose, maltotriose, glucose and limit dextrin from amylopectin. A number of saccharidases are attached to the microvilli, it is these enzymes that hydrolyze the starch fragments to monosaccharides in preparation for absorption by the microvilli. After monosaccharides are absorbed into the bloodstream the liver takes them up. Fructose and galactose are converted to glucose.