Background on Taste

Our taste senses vary by person. Some persons have been gifted by an extreme sensitive taste; however, this may be sometimes a problem too. Humans have taste buds that differentiate among sweet, sour, salt, bitter and umami (savory). We are least sensitive to sweet, more sensitive to salt and umami, and then again more sensitive to sour. Finally, we are the most sensitive to bitterness, likely since bitter alkaloids are meant to prevent most animals eating seeds of plants and thus preventing new plants to grow. But coffee, dark chocolate and beer lovers (hops in beer) know that the initial unpleasant taste of bitterness can be overcome.

Salty

Salt is tasted by the penetration of alkali metal ions. Salt is an acquired taste and eating regularly too salty food, seems to ask for more. It is better in these cases to dial down additional salt use, next to being more cautious on the salt content of food that is eaten.  With age the taste buds for salt seem to diminish and older people tend to eat more salty food. Many ready-made or processed foods contain a large amount of salt to masque other tastes and aid in preservation.

In the early times our diet contained more potassium than sodium, as vegetables and nuts were consumed and no processed foods existed (which are often high in sodium salt). Now in most cases our diet consists of more sodium than potassium. This means that the negative effect of sodium as a contributing factor to cause high blood pressure sometimes can be reduced by substituting sodium salt by potassium salt. This is why ‘Low salt’ formulations are offered based on this principle.  The use of salmiac salt (ammonium chloride) to provide licorice candies with a salty pallet is also well known and possibly does not contribute to high blood pressure by itself. However, the licorice root that contains a sugar with a very high sweetening effect causes high blood pressure.

Acid, sweet, bitter

Acid is sensed by the penetration of hydrogen ions in the taste buds. (lemon, lime, orange, tomato, crème fraiche, butter milk, vinegar, berries ……)
Sweet, bitter and umami are caused by interaction with the G proteins in the taste buds.

Umami

The umami taste is actually best described as the taste of L-glutamate, the salt anion of glutamine, a non-essential amino acid (non-essential meaning that under normal conditions the body produces this from food).  It was discovered by a German scientist, but commercialized by a Japanese professor in 1907.  Glutamine occurs in many foods, but the amino acid form does not have the savory taste and is not absorbed so quickly in the blood upon eating. The glutamate salt form is. Free glutamate occurs in all kinds of fermented food (Worcester sauce, soy sauce, fish sauce), but also in sharp cheeses such as Parmesan or Roquefort, seafood such as sardines, clams and mussels as well as in seaweed, mushrooms and green tea.   The separate addition of glutamate as a flavor enhancer to food does require to be labeled in Europe, but not in the US. In many Chinese and Japanese grocery stores sodium glutamate (labeled MSG) can be found on the shelf next to the salt.  But actually many savory foods have glutamate from natural sources in them.
Some people who eat food that has too much added MSG may develop an allergic or adverse reaction.  They should best prevent eating food with added msg.

How to create the savory taste? Fish, shell fish and crustaceans are rich in glutamate and other amino acids. Numerous savory tasting sauces are made from shrimp in South East Asia. China is using oyster sauce as a main savory enhancer. Fish sauce is made by fermentation of (dried), salted fish and is famous in Thailand, Vietnam and other South East Asian countries. Worcester sauce also contains fermented anchovies.

Mushrooms also contain amino acids and will form some of the glutamate. Tomatoes also contain naturally some sodium glutamate. 

Some types of dry broth cubes consist of salt, dried herbs, fat (usually palm) and MSG. Other broth cubes are based on hydrolyzed wheat proteins, thus creating the umami taste as MSG and related amino acid anions will be formed in the process

Other

Other factors that influence taste are texture, temperature, coolness, pungency, astringency, metallic flavor, and fatty taste. These items are sensed not on the tongue but elsewhere in the mouth. They are not defined as part of the five taste’s, but do have a large effect on how food and drinks taste.