cake does not bake long enough, the foam and gel structures will not reach their full potential. In a bakery, angel food cakes could be baked in a rack oven, revolving oven, convention oven, or small deck oven. A commercial bakery may use a tunnel or traveling oven. When the cake has finished baking, it should have a golden brown color on the exposed area. The final volume will generally be two to three times larger than the batter volume. Angel food cakes are cooled upside down. Some tube pans have "feet" or "fingers" that extend off of the top rim of the pan. The "feet" are placed on a cooling rack. If the pan does not have "feet" it is customary for home bakers to place a glass soda bottle or something similar through the tube to ensure that the pan is elevated. The elevation provides sufficient air flow to the cake, so that it cools properly. If a non-stick pan or greased pan were used, the cake would fall out when inverted, leading to a collapsed cake. Angel food cakes have a shelf-life of a few days at room temperature or up to a week in a refrigerator because of the tendency for moisture to migrate and evaporate. After a few days the cake will be dry and lack flexibility. Molecular and structural composition Egg whites Egg whites play an integral role in the structure of the baked cake. Egg whites are composed of many proteins; however, only ovalbumin, conalbumin, lysozyme, and globulins have properties which aid in creating a voluminous angel food cake. Ovalbumin and globulins will produce a foam that is equal to or greater than the size of the egg whites. Egg white proteins have many uses in baking, one of which is the ability to create and maintain a foam. Whipping incorporates air throughout the egg whites, as well as denaturing or unfolding the proteins to create thinner protein molecules. Overrun, similar to lightness, describes the amount of air pushed into the foam. In terms of an angel food cake, overrun is the increase in volume from the original volume caused by the inclusion of air. The overrun of an egg white foam ranges from 500 to 800%. This means that whipping 100 mL of egg whites would result in 500–800 mL of air incorporated into the foam. During whipping, protein adsorption allows for