Used as a thickening agent for gravies, sauces, pies and such, it is gluten-free. Corn starch turns translucent when cooked, is virtually flavorless and has twice power of flour to thicken liquids so you only need half as much. When used to thicken fruit pies, there is no need to cook the pie filling first. Rather, combine the cornstarch and sugar together and sprinkle over the fruit. The corn starch will thicken the fruit mixture as it bakes.