Umami - The Fifth Taste

The human sense of taste on the tongue and in the throat can distinguish various flavor profiles. These include bitter, sweet, salty, and sour. Additionally, since the early 20th century, there has been a fifth flavor profile under discussion. Chemist Kikunae Ikeda, based on his experiences with bitter, sweet, salty, and sour, suspected a fifth taste quality. Therefore, in 1909, he proposed the Japanese term "Umami" to designate this flavor profile. He identified glutamic acid as the essential carrier of this taste, which is found in the extract of Kombu (a seaweed that forms the basis for Japanese Dashi broth). Immediately after this discovery, Ikeda Kikunae, together with a business partner, began the production and isolation of monosodium L-glutamate from wheat proteins. In this process, gluten was hydrolyzed under the influence of hydrochloric acid, breaking down into its amino acids, with over a third being glutamine and glutamic acid. The crystallized salt of glutamic acid was sold as a sprinkleable seasoning under the trade name “Aji-no-moto” (Essence of Taste), first in Japan and later worldwide with great success.

How Can Umami Taste Be Best Described?

The taste of Umami is described as delicious, savory, and flavorful. It is not a component of the originally known taste profiles of salty, bitter, sour, and sweet, and cannot be produced by a combination of these elements. The Umami taste on the tongue is caused by the amino acid ions glutamate and aspartate, as well as the nucleic acid ions inosinate and guanosinate. This taste quality helps in identifying protein-rich food. It is found not only in artificially produced glutamate but also in numerous natural foods. Glutamate, for example, can be detected in tomatoes, olives, meat, beans, anchovies, and soy sauce. Even breast milk can have an Umami taste. Anyone familiar with the savory and slightly salty taste of broth, fried meat, fish soup, or yeast extract will know what triggers the Umami taste on the tongue. This gustatory perception can enhance appetite on the one hand and positively influence the feeling of satiety on the other.

Which Foods and Spices Generate This Flavor Profile?

In addition to glutamate as a flavor enhancer, various natural foods and spices can be used to create the Umami taste quality. For example, dried tomatoes, walnuts, kombu, and nori contain relatively high levels of glutamate. In the case of meat and fish, cured ham, duck meat, squid, and shellfish provide a particularly intense experience of this flavor profile. Cheese also contains glutamate, with Parmesan and Roquefort having the highest levels. Another source to indulge the taste buds with Umami is through soy sauces or fish sauces.

How Does the Human Utilize Their Sense of Taste for Umami?

By definition, the taste of Umami helps identify protein-rich foods. The more protein, the more intensely we perceive this flavor profile. This is well illustrated by examples such as dried tomatoes or ham. These foods taste more savory even if no salt or other substances have been added. This effect is achieved solely through the removal of water and the consequent higher concentration of glutamate. Interestingly, this preference has been known in Japanese cuisine for centuries and is utilized through fermentation, drying, and other special treatments, as well as combinations of different ingredients. Kombu seaweed imparts a delicious, aromatic flavor to the famous Dashi broth, a taste that is challenging to achieve with fish and other ingredients alone. When this Dashi broth is combined with Miso (a fermented paste made from soybeans), the natural flavor enhancer is perfected.

Utilizing Natural Glutamate for Flavor Enhancement

Glutamate is now used as a flavor enhancer in many foods, although increasingly less as the pure powder. Those who opt for natural seasoning can use ingredients such as soy sauce, mushrooms, tomatoes, cheeses like Parmesan, or beans for cooking to infuse vegan dishes with a touch of Umami. Those who cook Japanese or Asian cuisine will find numerous foods and sauces that can transform the taste of any soup or stir-fry with just a few drops. Perhaps this is why we enjoy tomato sauce so much, as tomatoes contain a high level of natural glutamate. By the way, the Umami taste intensifies when multiple glutamate-rich ingredients are included in the recipe. The receptors on the human tongue seem to multiply this effect, enhancing the overall taste experience. A famous example is Poulet Marengo, a dish prepared by Napoleon's chef using chicken, crayfish, mushrooms, and eggs – all ingredients with a relatively high glutamate content.

Is it harmful to season dishes with glutamate?

This question divides opinions. There have been various studies that observed headaches, numbness, palpitations, or hot flashes when consuming large amounts of glutamate. However, some of these studies are criticized. There were no double-blind studies or participants could choose whether they wanted to consume glutamate or not. One well-known concern is the Chinese restaurant syndrome, which was attributed to the excessive consumption of glutamate-containing condiments. However, more recent research suggests that other foods might be the trigger for these irritations. In a healthy diet, it is easy to avoid adding this flavor enhancer. Instead of concentrated powder, you can use naturally brewed soy sauces in moderate amounts, which are not too salty. You can also season excellently with kombu seaweed or mushroom powder. However, when using algae, it is important to be aware that they can contain very high levels of iodine. Kombu contains much more iodine than nori sheets or wakame and is therefore not consumed entirely but used subtly for seasoning.