The Umami Taste

The characteristic taste of monosodium glutamate and 5′-ribonucleotides is called "umami" in Japanese. It plays a predominant role in the flavor of foods, such as meats, poultry, fish and other sea foods, dairy products, or vegetables. The taste was first discovered by Ikeda (1908) (1), and has been studied by a large number of researchers from different points of view (refer to, e.g. 2-9). We have systematically investigated the umami taste using psychometric procedures. In this paper, a part of our studies will be outlined. Umami Substances Most typical umami substances are divided into two series of compounds. One is a group of L-α-amino acids represented by monosodium glutamate (MSG) (Table I) (10-15), and another is that including 5′-ribonucleotides and their derivatives, represented by disodium 5′-inosinate (IMP) or disodium 5′-guanylate (GMP) (Table II) (16, 17, 18, 19). The latter group of substances have only very Table I. Umami Substances Related to MSG Table II. Umami Substances Related to IMP weak tastes. It is notable,