Growing up, many of us were taught that the tongue could detect four essential tastes: sweet, salty, sour and bitter. Everything else, we were told, was a product of aroma and texture. But it always seemed like those four weren't enough to explain the whole range of tastes... could it really be that the only taste behind the deliciousness of a butter-doused morel mushroom, or a perfectly grilled steak, was salty?
The wide acceptance of umami, or savoriness, as the fifth taste helped some. (It was originally discovered by Japanese researchers at the dawn of the 20th century, but it's only been universally approved in the past couple decades.) Still, though, what about croissants? French fries? Are they really so delicious just because of their texture and smell?
Some researchers think not. An increasingly vocal group of food scientists believe that "fatty" represents a sixth taste entirely.
A widely-reported study supporting the idea of "fatty" as the sixth taste was published in March of 2010, by Russel Keast of Deakin University in Australia. And yet another came to light just this week. Both the studies predicate fatty's status as the sixth taste on the ability of some people to correctly identify 'fattiness' in the absence of the telltale signs of fatty foods. The theory goes that, if people can pick out fatty acids in foods that aren't luscious or crispy, and don't smell like rendering fat, that must mean that the tongue can respond to "fattiness" in the same way, or at least a similar way, to salt or sugar.
For the new study, researchers at Washington University in St. Louis asked 21 individuals with BMIs over 30 to taste three different solutions with the same texture. One of those solutions contained a small amount of fatty oil. The researchers asked the subjects to identify which of the solutions tasted fatty.
What they found was that some people were very adept at picking out the fatty solution and others were not. And many of those most able to identify "fattiness" shared high levels of the protein CD36, which suggests a genetic, biological basis for the taste sensation, rather than just a learned affinity.
Pretty soon, then, you might see a "fatty" condiment on your table right next to the salt and sugar.
Oh wait: that's just olive oil or butter. Bring it on!