Answer:
Refined grain products, such as flours and cornstarch, are used as thickeners in cooking.
Step-by-step explanation:
Refined grain products, such as flours and cornstarch are products that are obtained when grain products such as maize, rice, wheat , etc are milled and refined such that the bran and germ of the grain seed it lost during the milling process.
Flour is produced from grains by finely grinding and milling the whole grains in a very fine powder while cornstarch is made true a more refined process whereby the protein and fibrous part of corn grains are removed and all we have left is the endosperm which contains a lot of starch.
Flours and cornstarch, are used as thickeners in cooking the only difference is cornstarch has a lot of thickening power compared to flour.