Designation of Japanese origin for the now scientifically recognized fifth taste sensation that is perceived by the presence of glutamate in food or beverages. Chemically speaking, glutamate is the sodium salt of amino acid Glutamine. Amino acids are the basic building materials for proteins (Proteins). This substance develops taste-enhancing properties in foods and plays a special role in the palatability and acceptance of many foods. Glutamate (or glutamic acid) is found in almost all proteins as a building block, which means that it is consumed with almost every meal. Vegetable proteins can even contain up to 40% glutamic acid. Glutamate is not allowed gluten (Glue protein) can be confused.
Left picture (edited): Copyright: Peter Hermes Furian
Right picture (edited): Von NEUROtiker - Own work , CC BY-SA 3.0 , Link
In living cells, glutamic acid is necessary, among other things, for detoxification processes and as a source of energy. It is also the most important neurotransmitter for the transmission of stimuli between nerve cells. Only free glutamic acid or its salt works as a flavor enhancer. In food condiments such as Maggi or Knorr, the relevant proportion is glutamate. Particularly high concentrations of glutamate can be found in meat (especially when raw, such as beef tartar), in human breast milk (22 mg / l), in ripe tomatoes (140 mg / l, four times in tomato paste), in fish, in yeasts, in soy and in cheese (in matured Parmesan cheese even up to 1,200 mg / l). Pure glutamic acid tastes sweet and sour and intensifies the taste of salty foods.
The use of these properties has a long tradition in Far Eastern cuisine. Asian cooks used extracts from large ones over 1,500 years ago seaweed (Species Laminaria japonica) for food preparation. As early as 1908, the Japanese scientist Kikunae Ikeda (1864-1936) discovered that glutamate gives a full-bodied taste in protein-rich dishes. He called the flavor direction "umami". This means "meaty, hearty and tasty" or is also a synonym for "greatest delicacy" or "pleasant taste" and is also understood in Japanese for a particularly intensely experienced pleasure. Today, glutamate is used in numerous foods worldwide and according to the WHO FDI limit "Not specified". This means that it can be absorbed by humans without restriction. For a long time, glutamate was mentioned as the cause of the "China Restaurant Syndrome" with symptoms such as headache and nausea. However, this has not been confirmed in any way in double-blind tests.
In addition to the four traditional taste sensations bitter. salty. angry and sweet was discovered umami almost 100 years after the discovery of Ikeda in spring 2002 by the American scientists Charles Zucker and Nick Ryber at MIT (Massachusetts Institute of Technology) as a fifth taste (in 2006 it was also the sixth) greasy added). Until then, it had been assumed that the sensation was just a mixed taste of the other four. The receptors (Nerve cells) responsible for glutamate perception have been found in the taste buds of the tongue. And just like the other four, there are cells in the brain that umami explicitly receive and reproduce.
Since in Wine If amino acids are contained, umami could also be objectively recognized if they are present. The only problem is that according to the above studies, the receptors on the tongue are only weakly developed compared to the receiving sites in the brain (1 to 100). A phenomenon is that glutamate in combination with a wine containing bitter substances, such as in Barrique developed the case, the bitter effect intensified. This can be the case, for example, when enjoying parmesan cheese or smoked salmon, to which an in Oak barrels aged wine is enjoyed, the case. See also under taste and odor,