What is one primary role of starch in cooking?

Starch primarily functions as a thickening agent in cooking, making it essential for the preparation of sauces, soups, and gravies. When starch is heated in the presence of liquid, it absorbs water and swells, leading to a increase in viscosity. This process, known as gelatinization, creates a smoother and thicker texture that enhances the overall mouthfeel of the dish.

While flavor, color, and freshness are important aspects of cooking, they are not the primary roles of starch. Starch does not provide flavor; rather, it serves to create a base for flavors to adhere to and to improve texture. It does not enhance color significantly, as that role is more often fulfilled by pigments and other ingredients. Similarly, starch is not used to preserve freshness; preservation typically involves techniques such as refrigeration or the use of preservatives. Therefore, the ability of starch to thicken sauces and soups is the key aspect that validates this answer as the correct choice.