Some Premium foods make you think they're Super-Premiums. They're priced like Super-Premiums, but the ingredients list puts them back in the Premium category. To Eat Your dog needs to eat a food he likes. Most dogs do have preferences, and it's important to honor them. If your dog eats the food with vigor, he'll get all of the nutrition required.
Taste is a function of the ingredients used, as well as the flavorings added.
It's determined by test dogs who are allowed to choose one formulation compared to another. You can do your own palatability study by putting two brands in bowls side by side to see which your dog prefers. Many manufacturers use poultry or beef digests to enhance the palatability of their foods. For example, poultry digest consists of chicken or turkey parts that have been broken down by using chemicals or enzymes, resulting in a powder or liquid. This is included in the dog food mixture during processing, or sprayed on at the end of the process along with vitamins.