Researchers at the Monell Center in Philadelphia studying the functional olfactory receptors that detect odors found they're present in human taste cells on the tongue as well as in the nose. They said this suggests interactions between smell and taste, the main components of food flavor, could start on the tongue rather than in the brain.
Mehmet Hakan Ozdener, a cell biologist at the Monell Center who was the study's senior author, said taste and smell have always been considered independent sensory systems that didn't interact until their respective information got to the brain. He decided to investigate this belief after his 12-year-old son asked whether snakes extend their tongues in order to smell. The study was published in the journal Chemical Senses.
"Our research may help explain how odor molecules modulate taste perception," Ozdener said in a statement. "This may lead to the development of odor-based taste modifiers that can help combat the excess salt, sugar, and fat intake associated with diet-related diseases such as obesity and diabetes."
The researchers, using genetic and biochemical methods to study living human taste cells in a culture dish, found these cells contain many of the key molecules also present in olfactory receptors in the nose. They also used calcium imaging to show those cultured taste cells respond to odor molecules similar to olfactory receptor cells.
Their findings are the first demonstration that olfactory receptors may interact with taste receptor cells on the tongue, and as a result influence the human taste system, the scientists said. In other experiments at the Monell Center, they discovered a single taste cell can contain both taste and olfactory receptors.
If these findings prove to be reliable, they could help scientists better understand how odor and taste interact in humans. This insight could also help the food and beverage industry in developing and marketing certain products.
Manufacturers have long known the aroma of a food item can influence consumer purchases and enhance their eating experiences. Ingredient suppliers such as McCormick's and Ingredion are always on the lookout for flavors in other parts of the globe that could turn into the next trend.
While taste and smell aren't the only elements influencing consumers today — studies show they also care about a balanced diet and their overall health — these can be key aspects to a product's appeal.
Barry Callebaut has been exploring how consumers taste chocolate, with the company taking two years to research all the different subjective flavors that may be on hand in the product. There's appearance, aroma, mouthfeel, taste, texture and probably a few others at play when consumers try a food or beverage. Manufacturers may be able to harness these aspects to create and improve products to appeal to all of them, particularly as more information is discovered about how they interact from studies like this one.
To learn more about this mysterious connection between smell and taste, Monell Center scientists have other experiments in mind, including investigating whether olfactory receptors are located in a certain place for cells to detect things that are sweet or salty. They also want to know how odor molecules change the responses of taste cells and therefore how humans perceive taste.
This area of inquiry may hold vast potential in product development. As food manufacturers and retailers look for ways to stay ahead of their competitors, learning how senses interact could prove invaluable in how they design and market their products.