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Where does most starch digestion occur in the digestive system?

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A biochemical flowchart shows the metabolic pathways for carbohydrate utilization, including glycolysis, the pentose phosphate pathway, and the tricarboxylic acid (TCA) cycle. The diagram traces the conversion of glucose, fructose, and glycerol through various intermediates, leading to energy production, carbon dioxide release, and biosynthesis of amino acids and porphyrins. Key steps and branches are labeled, with colored boxes highlighting biosynthetic outputs. — Carbohydrate Pathways for the utilization of carbohydrates.

While starch digestion begins in the mouth through the action of salivary amylase, the vast majority of starch digestion occurs in the small intestine, specifically within the duodenum.123

In the duodenum, pancreatic amylase is secreted by the pancreas to catalyze the hydrolysis of the remaining starch molecules into maltose and other smaller carbohydrate units. These products are subsequently broken down into monosaccharides, such as glucose, by enzymes located in the brush border of the intestinal epithelial cells, allowing for final absorption into the body.23