What is the main purpose of using a marinade in cooking?

The main purpose of using a marinade in cooking is to tenderize and flavor food. Marinades typically consist of acidic components, such as vinegar, citrus juice, or wine, which help to break down tough protein structures in meat, making it more tender. Additionally, the ingredients in a marinade—such as herbs, spices, and oils—infuse the food with rich flavors, enhancing the overall taste of the dish.

While preserving food can be a function of certain ingredients in a marinade, such as salt or vinegar in some recipes, this is not the primary purpose of traditional marinades. The thickening of sauces involves different techniques like reduction or the addition of starches, while providing color usually pertains to cooking methods or the use of specific ingredients, rather than the marinating process itself.