Salt, Part 6: Please Pass The Salt
Salt is one of our five basic senses of taste, which also includes sweet, sour, bitter and umami (savory). Haven’t heard of ‘umami’ before? It’s kind of a recent thing, discovered and named by a Japanese researcher. Umami is the savory taste that is triggered by the seasoning common in Asian food, monosodium glutamate (MSG). Sweet, bitter and umami are detected by ‘G-Protein-Coupled Receptors’ (GPCRs) that detect a signaling molecule in our food and then send a signal to our brain with the relevant info. Salty and sour are detected by ‘ion channel proteins’, which conduct specific ions like sodium, calcium and potassium directly into our system. Because these ions are so important to the chemical balance in our body, we can detect and absorb them quickly. The chlorine in salt doesn’t play a serious role in how we detect the presence of salt in our mouth. Basically, we’re taste sensitive to the sodium ion in salt (Na+) and not the chlorine ion (Cl-).
While we may have only five basic tastes, humans have the ability to detect thousands of different odors. As a result, odor has as much to do with how we perceive the taste of food as does the actual taste we sense on our tongues. Food contains volatile compounds that vaporize easily and are detected as odors by our olfactory sense (that’s means, we can smell it with our nose!) Adding salt to food increases ionic concentration in the food, which causes more volatile compounds to vaporize. The result is that food with salt has more odor, and these odors are more complex, giving the food both flavor and character. Even more interesting, salt can reduce the bitter flavor in some foods and enhance the sweetness of food in which bitter flavors are present. Salt literally improves the flavor of the food!