As already mentioned, the tongue has receptors for the five basic tastes sweet, sour, salty, bitter and umami. The taste buds can adapt to the concentration of tastes. For example, if you consume a lot of sugar and then reduce it, after a short adjustment phase you will taste the natural sweetness of fruits and vegetables more intensely than before and perceive foods with the previous amount of sugar as too sweet. The same applies to the other flavors.
We learn to know and love the sweet taste as infants and remain closely attached to it throughout our adult lives. Sweetness is considered a taste of pleasure. It points to the ingredient sugar and thus a welcome source of energy to fuel the body.
Salt improves the taste of food and is a necessary component of human nutrition. Therefore, the most important taste receptor of the tongue is the salty taste receptor.
Sour taste buds detect hydrogen ions from organic acids in foods, whether they are citrus fruits, yogurt, or fermented vegetables such as sauerkraut. Everyone knows the feeling when everything tightens up at the very thought of licking a slice of lemon.
The tongue’s receptors for the taste of bitter substances are particularly sensitive, as many of them are toxic. The taste buds must be able to perceive many of these substances. Some bitter taste can pleasantly enrich a meal, such as roasted sesame seeds. Many people also find the bitter notes of coffee and dark chocolate pleasant.
The appetizing umami flavor was identified last. Adding one or more of the foods with a lot of umami to a dish, for example the particularly rich shitake mushrooms or tomatoes, creates a round basic taste that the tongue receptors perceive as delicious and palatable.