Ingredients used by cooks, from ancient to modern times, to increase the amount of "umami" or savory taste. Umami is one of the five basic human tastes (along with sweet, sour, salty, and bitter). This category is analogous to sweeteners, but instead of the underlying molecules being chiefly glucose or sucrose, these umami sources are all rich in glutamate. In fact, chefs can often swap glutamate-heavy ingredients, e.g., swapping soy sauce with fish sauce -- because the underlying chemistry is similar.