ABSTRACT
The importance of starch lies in its dominance as a food component and the significance of its physical properties to food stability and texture. Starch is the most common carbohydrate polymer in foods. It is obtained from cereal and legume seed endosperm, potato tubers, and other plant reserve organs, and exists in the form of granules. The size of starch granules varies depending on their origin over the range of 1 to 100 jam. The granules are insoluble in cold water and composed of two glucose homopolysaccharides forming amylose and amylopectin molecules. Amylose is a linear polymer of l-»4 linked a-D glucopyranosyl units, while amylopectin is a branched polymer of a-D glucopyranosyl units primarily linked by l->4 bonds with branches resulting from 1->6 linkages. The properties of these two major starch components are summarized in Table 2-1. The amounts of amylose and amylopectin differ significantly in various starches; the amylose content of a number of starches is shown in Table 2-2. In native granular starches, amylose exists in the amorphous noncrystalline state, and crystallinity is attributed to short chained clusters of amylopectin (Whistler et al., 1984; Biliaderis, 1991, 1992).
