Common categories of flavors include sweet, sour, salty, bitter, and umami. The first four are very common and readily identified by all food consumers. Umami however, is a term that is not well known. First used by Asians, umami is a term that attempts to identify flavors that are meaty, robust or savory. It is also used to describe flavors enhanced by naturally occurring substances in foods such as glutamate, an amino acid that exists within bonito flakes, cheese, fish, kelp, mushrooms, soy sauce, and tomatoes. If the substance exists in its "free form" and is not bound to other substances, it enhances the flavor, thus providing umami to the foods being prepared.
Umami is a word commonly used to describe the flavor or taste of foods that are aged or allowed to ferment. Wine and cheese are two food items that may be described with this term, when referring to a strong, robust well-rounded, full-bodied, or meaty flavors. Also, when foods are added as ingredients to enhance the flavors of other foods, such as adding broth, stock, wine, or cheese to a food dish, it assists to increase the depth of the meat flavors or flavors of other main ingredients in the food dish, making the umami more intense.
USDA Nutrition Facts