Why add starch when so much is present in the flour already? Half to two-thirds of cereal grain flours consist of starch. It is the main carbohydrate of the baking industry. So why add more to a formula?

“Food starches provide the bulk, or body, for all baked goods, gluten-free or not,” said Matt Gennrich, research food technologist, Cargill. “Starches are also key ingredients in determining finished product texture and flavor.”

They do this on their own, but these materials also may be modified to achieve the functions of stabilization and structuring faster and in more controlled ways. Native unmodified starches require heat to activate their viscosity modification functions — thickening — and are described as cook-up starches. Their chemistry must be modified to get them to swell in unheated solutions, hence the development of pregelatinized and cold-water-swelling starches.

At its most basic, starch is made of glucose molecules connected in chains, some long, some short and some highly branched. Starches from different plant sources show widely varying structure, and they act in diverse ways.