Why did the salt taste like sugar?

Why salt makes sweets sweeter

Why does a pinch of salt make sweet pastries sweeter? And why do sweets taste less sweet when we are full? American researchers have now discovered a surprising explanation for these questions: In addition to the well-known sweet receptor, there are additional sensors in our tongue that also influence the respective sweet taste. As they report in the “Proceedings of the National Academy of Sciences” (PNAS), there are some sensors that are also found in the intestines and pancreas.

We owe the fact that we can taste sweet things to the sensory cells in our tongue that specialize in sweet taste. They accumulate especially on the front edge and on the sides of the tongue and react to sugars such as glucose, fructose and numerous molecules of artificial sweeteners. It has been known for some time that the primary mechanism is based on a two-part receptor in the “sweet sensory cells”. Strangely enough, however, these cells seem to be able to register sugar even if they lack part of this receptor.

Additional sweet sensors in the tongue

Researchers at the Monell Chemical Senses Center and the University of Utah have now found a surprising explanation for why: With the help of the most modern analysis techniques, they discovered, in addition to the main receptor, several other sensors in the sweet sensory cells of the tongue that also regulate the detection of sweetness. Interestingly, these additional sensors are by no means unknown; on the contrary, they are old acquaintances: They are also found in our internal organs such as the intestines and the pancreas. Here they act, among other things, as important regulators of blood sugar and digestion.

“The taste system amazes me again and again with how clever it is and how well it integrates the sense of taste with the digestive processes,” explains molecular biologist Robert F. Margolskee from the Monell Center. The researchers suspect that the various newly discovered sugar sensors also play different roles in recognizing the sweetness.

Sugar transporter reacts to salt

One of the newly discovered glucose sensors in the sweet-sensitive taste cells, for example, could explain why we have the feeling that cookies or cakes taste even sweeter when a pinch of salt is added to the dough. Known as SGLT1, this sensor is actually more of a transporter that deliberately injects glucose into the taste cells - but only when sodium is present.

Sweet tastes less sweet when we are full

Another newly identified sensor in the taste cells, the so-called KATP channel, normally monitors the glucose levels in the pancreas and releases insulin if they rise too high. The researchers suspect that this sensor in the tongue could have the function of influencing our sense of sweetness depending on the supply situation. For example, if we have just eaten a piece of cake and our sugar levels are high enough, it makes the taste cells less sensitive, so that we no longer perceive the next sweet as quite as sweet.

"The Süß cells turned out to be quite complex," explains Karen K. Yee, cell physiologist at the Monell Center and lead author of the study. “The presence of the KATP channel suggests that taste cells also play a role in regulating our sensitivity to sweet taste under different nutritional conditions. This knowledge could one day help us understand how we can limit the excessive consumption of sweet foods. "

(Monell Chemical Senses Center, 3/8/2011 - NPO)

March 8, 2011