Dr. Douglas Goff at the University of Guelph helped us with this one. And guess what? There’s no short answer. There are probably more than 100 different types of starches available for use as food ingredients, and all have been tweaked in some way through various chemical or physical reactions, to make them more useful. Starches are used for thickening—pudding, gravies, etc.
    Corn starch has two components, amylose (a straight chain polymer of glucose) and amylopectin (a branched chain polymer of glucose). In nature—for example, in corn—it is found structurally in a granule. Corn starch is “sticky”. But, when you extract the starch from corn and then use it as a food ingredient, it quickly loses that stickiness when heated. And it can cause bakery products to become stale.
    How food scientists modify the starch depends on how it will be used. It can be cross-linked (chemically treated to cross-link starch molecules in the granule), for example, so it swells but doesn’t fall apart. Or it can have various derivative units added to it so it doesn’t stale as easily.