Potato starch

Cornstarch can also be replaced with potato starch. Potatoes are dried into a powder after being smashed to release their starch content. It's not a grain, like arrowroot, thus it doesn't have gluten. However, because it is a refined starch, it is high in carbohydrates and low in fat and protein.

Like other tuber and root starches, potato starch has a rather mild flavor and won't add any unwanted flavor to your dishes. You should use potato starch in a 1:1 ratio in place of cornstarch. This means that you should substitute 1 tablespoon of potato starch for 1 tablespoon of cornstarch. It's also important to remember that many cooks recommend adding starches from roots or tubers, such as potato or arrowroot, later in the cooking process. This is because they thicken and absorb water much more quickly than starches made from grains.