Potatoes and corn are both starchy vegetables that make for great thickening agents when processed into pure powdered potato starch or cornstarch. Stews, stir-fry sauces, pie fillings, and more can benefit from these pantry staples, but there are some big nutritional and culinary differences between the two products.

Potato starch is made of potatoes soaked in warm water and dehydrated into a powder, and the resulting product has little nutritional value. However, it is lower in calories and carbohydrates than cornstarch, and works well with high-temperature cooking for shorter periods of time, making it a great last-minute thickener in recipes.

Cornstarch is made from the inner layer of corn kernels, and doesn't contain many vitamins or nutrients, much like potato starch. However, cornstarch is the best thickener for longer, lower-temp cooking processes, and has a lower glycemic index, meaning the body digests it more slowly and it's less likely to spike blood sugar levels.

Potato starch and cornstarch are both gluten-free, and are interchangeable in certain applications, like pie fillings and soups that don't cook for very long. However, cornstarch can give foods a spongy texture once they are frozen and thawed, so potato starch should always be swapped in for recipes you plan to freeze.