Bakery Processes, Chemical Leavening Agents

Abstract

AbstractChemical leavening involves the action of an acid on bicarbonate to release carbon dioxide gas for aeration of a dough or batter during mixing and baking. The aeration provides a light, porous cell structure, fine grain, and a texture with desirable appearance along with palatability to baked goods. There are essentially two components in a chemical leavening system: bicarbonate that supplies carbon dioxide gas and an acid which triggers the liberation of carbon dioxide from bicarbonate upon contact with moisture. Sodium bicarbonate (baking soda) is the primary source of carbon dioxide gas in practically all chemical leavening systems. The prevalent baking acids in modern chemical leavening systems are sodium or calcium salts of ortho, pyro, and complex phosphoric acids. Baking soda determines the amount of carbon dioxide evolved, whereas the type of acid controls the speed of liberation. By far, the greatest use of leavening in the home is in preleavened mixes. Pancake mixes, biscuit mixes, and cake mixes have long been established as commercial products. Sales of frozen or refrigerated doughs and batters have increased rapidly in recent years. This trend is attributable to increased refrigeration and freezer capacity in stores and to the development of new and improved ingredients. Practically all of the leavening acids used in the mix industry today are of the phosphate type. The blending of baking powder is essentially a physical mixing of the various components in a large‐scale batch mixer and is often carried out in automated plants.