The shortening power of certain fats make them essential in the preparation of pastries, pie crusts, biscuits, and cakes. The more highly saturated fats tend to have greater shortening power. Incorporated into a flour mixture, fat separates the flour’s starch and protein and, when heated, melts into the dough, leavening the air spaces that give the finished product its characteristic delicate texture. A fine grain is created from certain cake and cookie batters with the use of shortenings that gently encase the numerous air bubbles, serving as a starting point for the air to expand and increase overall volume. Baked goods also become more tender, up to a point, as fat concentration increases.