Without salt, your favorite foods such as french fries, potato chips, and chocolate chip cookies would all taste bland. And that’s because salt has lots of effects on flavor perception than just making things more salty.
Many say a spoonful of sugar helps the medicine go down, but a pinch of salt, in fact, does the work better. How is that? And why does salt make food taste better? Hank Green from SciShow explains.
Our brains are hardwired to crave salt because we need it to survive. Salt – usually sodium in the form of sodium chloride— is an essential nutrient, and our body uses it for everything from regulating fluids, blood pressure and to creating nerve impulses. But, our body can’t make sodium by itself, so we have to get at least some of it from our diet.
Humans mostly taste saltiness, thanks to epithelial sodium channels (eNaC), which are basically pores that allow sodium ions to pass into the taste receptors cells (TRCs) in the taste buds. TRCs then tell the brain that something’s salty.
Salt also makes things sweeter. Our intestines are full of sugar sensors, and our mouth has some of them too. In fact, many humans’ organs have sugar sensors and their job usually is to process glucose and insulin in the blood. However, intestinal glucose sensor (SGLT1) has another job in our mouth: it pushes glucose into the sweet taste cell when it senses the presence of sodium in the food, thus “triggering the cell to register sweetness.”
Salt also suppresses bitterness better than sugar. Researchers haven’t completely figured out the mechanism for it, but study suggests it involves both the tongue and the brain. Most of the bitterness-blocking happens in the taste buds, and what researchers think sodium does here is that it interferes with the binding between bitter compounds and their taste cell receptors.
“If you’re given salt and a bitter compound in such a way that they don’t mingle on your tongue, you still perceive the overall flavor as slightly less bitter” Hank explains in the video. “That suggests some of the anti-bitterness effect comes from how your brain interprets multiple taste signals when they include saltiness.”
Salt also makes food taste better by making them smell better. The ions in the salt are attracted to some of the available water in the food. So adding salt to foods makes it easier for volatile compounds — molecules that evaporate quickly and often contribute to aroma of the food — to escape into the air. These compounds may not hit our tongue, but they are important in our perception of flavor.
“Salt also seems to do other things to make food more enjoyable … although scientists can’t really explain them yet,” says Hank. “For instance, volunteers in a 1985 study said salted split pea soup was not only saltier, sweeter and less bitter than the unsalted version — it was also thicker and fuller, altering what food scientists call mouthfeel.”
After all, saltiness is one of the fundamental flavors of human taste – maybe this also partially explains why it enhances flavor. Other tastes human tongue can detect are: bitter, sweet, sour, and umami (savory taste).