Fat, long believed to provide texture in foods but not add a taste of its own, does in fact have a distinctive taste, and it's different from the basic tastes scientists have always agreed on, researchers report.
To the recognized flavors humans can detect – sweet, sour, salty, bitter and umami (bland, think MSG in your Chinese food) – we can add a sixth one, say researchers at Purdue University.
They've dubbed the taste of fat, which is distinct and generates brain activity different from what other tastes invoke, as oleogustus, from the Latin words for oil and taste.
Fat has long been considered simply as a carrier of other taste and odor compounds in foods, and as a dietary component giving texture and "mouth feel" to foods.
However, the Purdue researchers report they've identified a flavor in fat that humans can taste, making it a sixth basic taste.
The finding could have implications for research into obesity, they say, and could be why humans don't find fat-free foods as appetizing as their counterpart foods laden with fat.
"I wonder if the less-than-perfect performance of current fat replacers may be due to a lack of understanding of all mechanisms for fat perception," says Richard Mattes, a Purdue professor of food and nutrition. "Failure to account for a taste component may compromise quality."
In the Purdue study, volunteers where given nose clips so they wouldn't confuse the aroma of foods for taste, then asked to sort and identify concentrated samples in terms of sweet, sour, salty, bitter or bland.
Sixty-four percent of the participants could distinguish a taste in a fatty acid sample that was distinct from the other recognized tastes, the researchers report.
What surprised the researchers was that the volunteers found the taste of fat, in its pure form, to be unpleasant.
It is only when the fat taste was combined with other tastes – for example, salt or sugar – that it became tempting and satisfying, enhancing a food's taste by several times, the researchers say.
That's likely why junk foods laden with fat are so attractive, they point out.
Understanding how the body "tastes" fat could yield insights into how the body metabolizes foods, and perhaps lead to better understanding of the underlying causes of obesity, they say.
There are other health consideration as well, says Mattis, who notes that elevated levels of triglycerides, a main component of fat, are associated with increased cardiac risk in a person.
