Corn starch is used as a thickening agent in liquid-based foods (e.g., soup, sauces, gravies, custard); it is mixed-in with a lower-temperature liquid to form a paste or slurry. It is sometimes preferred over flour because it forms a translucent mixture, rather than an opaque one. As the starch is heated, the molecular chains unravel, allowing them to collide with other starch chains to form a mesh, thickening the liquid (Starch gelatinization).