Polysaccharides such as starch and pentosans are high-molecular-weight polymers of monosaccharide units. Starch consists of amylose (linear α-1,4-glucose chains) and amylopectin (branched α-1,4 and α-1,6 chains), serving as the primary energy storage carbohydrate in plants. Pentosans, including arabinoxylans, are hemicelluloses composed mainly of pentose sugars like xylose and arabinose linked by β-1,4 bonds. In food systems, they contribute to texture, water retention, and viscosity. Starch gelatinizes upon heating in water, forming pastes used as thickeners. Pentosans influence dough rheology in baking. Both are biodegradable, non-volatile, and exhibit low reactivity under normal conditions. They are widely distributed in cereals, tubers, and plant cell walls.