Posted on Sep 13, 2016, 6 a.m.
Researchers have discovered a sixth taste, which may explain why people love carbs.
Scientists are looking at a sixth sense humans have, based on their love for foods rich in carbohydrates. The new taste sense could lead to the discovery of a new flavor, which could easily be added to a growing list of already acquired tastes, including salty, sugary, bitter, sour and umami foods. It could also explain why people cannot get enough of starchy foods. Lead researcher from Oregon State University, Juyun Lim believes that this discovery could account for why people prefer complex carbs. Sugar tastes fantastic in short-term, but when humans are asked to choose between chocolate and bread, they would choose a small portion of the chocolate, and larger amounts of the bread, or consume as a daily staple.
The study began with 22 subjects who were asked to consume a variety of different solutions made from different types of carbohydrates. During the test, the subjects were asked to put a value on each solution they tasted. They described the taste as "starchy." Asian subjects described the taste as "rice-like", while caucasian subjects described the taste as pasta or bread-like. According to Lim, the taste of the solutions is nothing short of eating flour, at least that is how it tastes.
Afterwards, the test subjects were introduced to a special compound that specifically blocked the sweet taste receptors found on their tongues. They were also given another compound that blocked the enzymes that are used to dissolve long-reacting carbohydrates. This step of the study was crucial, because up to this point the general belief was that people couldn't taste carbohydrates. This was based on the idea that carbs break down rapidly, and only the sweet tasting residue is left behind. As science would have us believe, it is only the sweet tasting molecules that we are actually tasting. The subjects continued to be able to taste and to describe the starchy taste, after the blockers were administered.
Despite the previous theory that humans cannot taste carbs, the truth became quite evident. Every culture has their main source of complex carbohydrates. The idea that no one can taste what they are eating does not make much sense, says Lim. These latest results can also explain why humans have a long history of eating starchy foods such as bread and rice. These two starchy foods have been a part of human culture for centuries. With one solid hypothesis to hold on to, the research team is hoping to identify the exact receptors, associated with picking up the sixth taste, that are on the tongue.
Additionally, starch is not the only new taste scientists are looking into. In 2015 scientists found that fat might have a taste of its own, as well. Singularly, fat is a dull tasting flavor, however it enhances other flavors in a manner similar to bitterness. Yet another team of researchers is looking into the possibility that that tastes such as blood, amino acids and calcium could be separate tastes as well.
Whether these new tastes make it to the official taste list is unclear at this point. Nevertheless, one fact is clear. Humans are not in tune with their own mouths and senses when it comes to taste. Hopefully, one day soon, this will all change and there will be a clearer understanding of this basic daily function.
Chem. Senses (2016) doi: 10.1093/chemse/bjw088 First published online: August 23, 2016