There is a sixth taste and its fat!

Researchers have increased the number of taste from five to six suggesting that 'fat' should be considered as a taste and can be called oleogustus.

Researchers have increased the number of taste from five to six suggesting that ‘fat’ should be considered as a taste and can be called oleogustus.

Purdue University researchers explain that most of the fat that we consume is in the form of triglycerides, which are molecules comprised of three fatty acids. However, these triglycerides are not the reason behind the new taste. The fatty acids that are cleaved off the triglyceride in the food or during chewing in the mouth stimulate the sensation of fat.

Researchers say that though the taste component of fat is often described as bitter or sour because of its unpleasantness, they have found new evidence that fatty acids evoke a unique sensation that satisfies another element of the criteria for what constitutes a basic taste, just like sweet, sour, salty, bitter and umami.

The study suggests that building a lexicon around fat and understanding its identity as a taste could enable the food industry to develop better tasting products and with more research help clinicians and public health educators better understand the health implications of oral fat exposure.

The researchers proposed “oleogustus” as a way to refer to the sensation. “Oleo” is a Latin root word for oily or fatty and “gustus” refers to taste.

Richard D. Mattes, distinguished professor of nutrition science at the University, said the taste of fat should not be confused with the feel of fat, which is often described as creamy or smooth.

Though fatty taste itself is not pleasant when concentrations of fatty acids are high, researchers say that low concentrations of fatty acids in food may add to their appeal just like unpleasant bitter chemicals can enhance the pleasantness of foods like chocolate, coffee and wine.

Because there are no familiar words to ask people to use to describe the taste of fat, the 102 study participants were given multiple cups of solutions each containing a compound that tastes salty, sweet, umami, bitter, sour or fatty. The participants were asked to sort the solutions into groups based on which had similar taste qualities. Odor, texture and appearance were all controlled.

The panelists easily segregated sweet, salty and sour samples confirming they understood the task. Initially, the fatty samples were grouped with bitter because bitter is the vernacular descriptor for unpleasant taste sensations. However, when asked to sort samples including bitter, umami and fatty stimuli, panelists grouped the fatty acids together and separately from the other samples, Mattes said.

In addition to this study, Mattes and collaborators are also analyzing data from more than a thousand participants in a study related to the genetics of fat taste at the Denver Museum of Nature & Science’s Genetics of Taste Lab. Mattes is director of Purdue’s Ingestive Behavior Research Center and he is also known for his work related to nuts and beverages.

The findings are published in Chemical Senses.