Scientists from Purdue University in Lafayette, Indiana, in the US have discovered a sixth taste – fat. The researchers have labelled this recently discovered taste oleogustus. Oleo is a Latin root word for oily or fatty and gustus refers to taste.

The taste of fat is often described as bitter or sour, but most people in the study were unable to find a word to describe it.

Initially participants confused the taste of fat and the taste of umami (a rich savoury taste) but later they distinguished them. Researchers said the overlap was most likely due to unfamiliarity with umami sensations rather than true similarity.

Richard Mattes, professor of nutrition and co-author of this report said: “By building a lexicon around fat and understanding its identity as a taste, it could help the food industry develop better-tasting products. With more research, doctors and public health educators could get a better understanding of the health implications of oral fat exposure.”

The findings are published online in Chemical Senses, and the work was supported by a US Department of Agriculture Hatch Grant.

Taste

Mattes said the taste of fat should not be confused with the feel of fat, which is often described as creamy or smooth.

“Fatty taste itself is not pleasant. When concentrations of fatty acids are high in a food it is typically rejected, as would be the case when a food is rancid. In this instance, the fat taste sensation is a warning to not eat the item. At the same time, 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.”

In addition to this study, Mattes and collaborators are also analysing 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.