Sixth taste discovered making food more delicious

According to an article recently published in the Washing Post, scientists have discovered a new taste that could make food more delicious.

Our kids learn about taste in grade school, and out of the five senses, taste appears to be one of the simplest. There are no tympanic membranes, miniscule bones, cones, rods or lenses. Yet scientists know less about taste than they know about sight and hearing - senses that are far more complex.

Why is taste, which is so apparently elementary, so mysterious, complicated and controversial then?

Well, to start with, most people confuse taste with flavour. Taste is a chemical sense perceived by specialized receptor cells that make up taste buds. Flavour, on the other hand, is a fusion of multiple senses. To perceive flavour, the brain interprets not only gustatory (taste) stimuli, but also olfactory (smell) stimuli and tactile and thermal sensations. With spicy food, for example, the brain will even factor in pain as one aspect of flavour.

Until recently, scientists have accepted four basic tastes. We all know them well – bitter, sweet, salty and sour. They are at the root of other tastes and the building blocks of flavour. The basic tastes went unchallenged for years, but in the early 1900s, a Japanese scientist, named Kikunae Ikeda sought to detect a fifth taste, naming it umami, which is triggered by monosodium glutamate, or MSG, as it's more widely known. Umami is a Japanese word meaning delicious, savoury taste, which you can taste in meats and tomatoes. It is also particularly prevalent in truffles, meat and anchovies.

Scientists believe they have now found a sixth basic taste that could profoundly change the way we eat. Evidence has been found, that fat interacts with our taste buds in a way similar to the five basic tastes. To conclude the research, Richard Mattes, a professor of nutrition science at Purdue University, and the lead author of the study conducted two experiments, involving 100 participants. They were asked to differentiate between and isolate the six different tastes: sweet, salty, sour, bitter, umami and fatty. It was only after the participants had trouble identifying between bitterness, umami-ness and fattiness, that another experiment was conducted, isolating these three tastes.

The Washing Post reports: "It was really very telling," said Mattes. "We already knew that people have a taste receptor for fatty acids; now we know that it's a distinguishable taste — that it doesn't have overlap. The combination of those two things is what's important." If people learn to manipulate the taste of fat correctly, he says, it will allow us to make tons of food taste better by either reproducing the taste of fat or introducing substitutes that successfully mimic it. "We could isolate it and use it in the same way we have used the other basic tastes," said Mattes.

Clearly, many of us enjoy fatty foods, from steak to pretty much anything that is fried. Fat is a tremendous source of calories and eating it is encouraged by our brains to have us survive. In an article published in Live Science in 2011, Michael Tordoff, a behavioral geneticist at the Monell Chemical Senses Center in Philadelphia reports, “There is no accepted definition of a basic taste, the rules are changing as we speak."

Our ability to sense the five accepted categories comes from receptors on our taste buds, with as many as 100 taste receptors on each taste bud. These tiny sensory organs appear mostly on the tongue, the roof of the mouth and in the back of the throat. How we experience a mouthful of food hinges on how the chemicals in the foods interact with the receptors on our tongues. The basic tastes blend together like primary colours to produce wildly different illustrations and masterpieces of flavour.

When you look at the colour orange, you don't immediately perceive that it is a combination of red and yellow. In the same vein, when you eat a food that contains fat, you don't immediately perceive the taste produced by the fatty acid. But it's there, and it's distinct. The article also reports that the sense of touch plays a key role in experiencing taste, as evidenced by the strong opinions on crunchy versus smooth peanut butter. Smell, too, impacts our tasting abilities. In the mouth itself, though, food scientists continue to discover new receptors and new pathways for gustatory impressions to reach our brain.

Like with primary colours, a primary taste can only be recognized as such if it doesn't share characteristics with other primary tastes. The fact that people can so easily recognize fat as a unique sensation in this context is evidence that it is a primary taste, especially since it already meets all of the other qualifications.

On its own, fat isn't reminiscent of bacon or lard. In fact, it's quite bland and doesn't taste very good. Neither does the bitter taste or MSG. In the way sugar, sodium and MSG have been used to enhance the taste of different foods, fat could soon be used too. One can only imagine what it will mean for flavour when the taste of fat can be sprinkled on top of a dish and how it can greatly contribute to the appeal of foods.

"Our understanding of primary colours, of vision, has allowed us to use that for creating art, for improving vision and for a wide array of everyday needs," said Mattes. "The better we understand our sense of taste, the better we’re be able to improve the taste of our food."

The impact of Mattes research could extend well beyond the reach of his lab. They might very well end up affecting what is on your plate, and, more specifically, how it tastes. "Understanding this could have huge implications for the food industry," said Mattes. "It could make a lot of food taste a lot better."

Sources: Washington Post and Livescience.com