Gelatinization of Starches

Polysaccharides are starches that are commonly used as thickening agents in preparations such as sauces and fillings. They are complex carbohydrates composed of two types of starch molecules, both of which are made of long chains of dextrose. One type, amylose, exists in long linear chains, and the other, amylopectin, in dendritic (branched) patterns. The ratio in which the two types of starch molecules occur in a starch will dictate its use. The higher the percentage of amylose, the more prone the starch is to gel. The more amylopectin present, the more the starch will act to increase viscosity or thicken without causing a gel to form. Starches high in amylose are derived from grain sources such as wheat and corn, while starches with a high percentage of amylopectin are derived from roots and tubers, such as tapioca.