Most natural carbohydrates are polysaccharides. Like oligosaccharides, polysaccharides are also complex carbohydrates.Starch is the main polysaccharide used by plants to store glucose and is the most common form of edible polysaccharide. Starch When humans eat starch, an enzyme called amylase – found in our saliva and intestines – breaks down the starch and allows the glucose to be absorbed into the bloodstream. Once absorbed into the bloodstream, the human body uses insulin to disperse and distribute the glucose to areas and cells where it is needed for energy or stores it as “liquid fuel†– glycogen. Dietary Fiber Some polysaccharides have an even more complex molecular structure and are known as dietary fiber, or "non-starch polysaccharides". These types of polysaccharide carbs include
- cellulose
- hemicellulose
- pectin
- gum and mucilage
Cellulose cannot be digested by the human digestive system, so cellulose passes through the digestive tract without being absorbed.But even though cellulose fiber can’t be converted into energy, it remains essential for a healthy diet because it helps to “exercise†our intestines and keep them clean and healthy. Some animals, (like cows), contain bacteria in their digestive tract that help them to metabolize and digest cellulose. Cellulose and most types of hemicellulose are known as insoluble fibers, while pectin, gum and mucilage are all soluble fibers and easily dissolve or swell when mixed with water.