Fat: The Sixth Taste

We have all heart about salty, sweet, sour, bitter, and umami; but have you heard of oleogutus? Well, there's a new flavor in town, and its name is oleogustus—the taste of fat.

What classifies a basic taste?

To be considered a basic taste, a flavor must meet five criteria. First, there must be a chemical stimulus which activates specific receptors on our taste buds. The chemical signal must travel from the receptors to the brain, and the brain must be able to identify the taste. The entire process has to trigger physiological effects on the rest of the body.

The reason why fat has not been a known taste for so long is because it is tricky to determine if fat can be perceived by the brain. While most people have a hard time describing the taste of fat, they're still able to tell that it's different from the basic flavors. However, our perception of oleogustus isn't the same as the other tastes. When we eat something salty, we instantly identify it as saltiness, but with fatty acids, we don't have the same instant perception.

Taste of Oleogustus

When we think about the taste of fat, we often associate it with the creamy texture that comes with it. This texture is caused by triglycerides, which are composed of several fatty acid chains. However, triglycerides have no effect on our taste buds, so they are not the source of taste. Chewing breaks down triglycerides which then allows fatty aside to release flavor.

In a study done by Purdue University, 102 participants were given numerous cups containing mixtures that each tasted sweet, salty, bitter, sour, umami or fatty, and they were asked to group them together based on similar flavors.

The participants were able to distinguish sweet, salty and sour flavours, but when it came down to the fatty mixtures, they initially classified them as being bitter due to the unpleasant taste. Later, when they were asked to group together bitter, umami and fatty samples, the participants grouped the fatty flavors together and were able to distinguish them as being separate from the rest. Based on these results, fatty acids can be differentiated as a separate flavor.