Starch can be considered a polymer of glucose. Its functions extend beyond food consumption: industrially, it is used to produce dextrin, maltose, glucose, and alcohol. It also serves in preparing printing pastes, sizing textiles, coating paper, and compressing pharmaceutical tablets. Starch can be extracted from starch-containing materials like corn, sweet potatoes, wild acorns, and kudzu root.
1. Energy Supply for the Human Body
Starch serves as a nutrient reserve in plants, stored within seeds and tubers. Most plant species contain significant starch content: rice contains 62%–86% starch,wheat contains 57%–75%, corn 65%–72%, and potatoes over 90%. As a key food component, chewing rice imparts a slight sweetness because salivary amylase hydrolyzes starch into the disaccharide maltose.After entering the gastrointestinal tract, starch is further hydrolyzed by pancreatic amylase. The resulting glucose is absorbed by the small intestinal wall, becoming nutrients for bodily tissues. Partial hydrolysis of amylopectin produces a mixture called dextrin. Dextrin is primarily used as a food additive, adhesive, paste, and in paper and textile manufacturing (finishing).
2. Hydrogen Production
Within the human body, starch is first broken down by salivary amylase into maltose, which is then further broken down into glucose. Glucose undergoes glycolysis to produce pyruvate; alternatively, starch may be directly broken down into the glycolysis intermediate glucose-1-phosphate (this portion did not have sufficient time to mix thoroughly with saliva). Pyruvate is then produced.Pyruvate then combines with enzymes to form acetyl-CoA. This enters the citric acid cycle, where citric acid is first produced. Within the citric acid cycle, each glucose consumed generates 6 NADH and 2 FADH₂ (electron carriers). Within the mitochondrial membrane structure, these electrons generate large amounts of ATP and energy via ATPase.
The Role of Starch in Other Food Preparations
Beyond cooking, starch plays a significant role in various food processing. Foods utilizing starch as an ingredient or main component include: various types of stuffed intestines, stuffed tripe, jelly noodles, glutinous rice balls, starch sheets, vermicelli, ham, and monk's tripe.