The quest for umami

Abstract

More than a century after Kikunae Ikeda in 1909 proposed a fifth taste quality, umami, as a basic taste, many people and even chefs, in particular outside Japan, still struggle with a clear perception of umami in their food. Often umami is used incorrectly as synonymous with deliciousness and a lucky combination of the four classical basic tastes along with a pleasant mouthfeel. Umami is now known to be elicited by the stimulation of umami receptors in the taste buds by the interaction with free amino acids, in particular glutamate, often in synergy with free 5'-ribonucleotides, such as inosinate, adenylate, and guanylate. Umami is an important component in the koku attribute by enhancing continuity and mouthfullness of the overall taste experience. In order to determine if certain foodstuff elicit true umami, we have undertaken a quantitative analysis of the free amino acid contents of various foodstuff and food preparations often claimed to have umami, in particular fermented sauces, seaweeds, cephalopods, and sous vide-prepared meat. We find that in some cases these kinds of foodstuff, even if delicious, do actually contain very little free glutamate.