Retronasal smell
Flavor should be contrasted with taste, which refers to five specific dimensions: (1) sweet, (2) salty, (3) bitter, (4) sour, and (5) umami.
[1] Avery Gilbert, in his book The Nose Knows, reviews the work of Henry T. Finck, an American philosopher from the late 1800s who published a groundbreaking essay titled “The Gastronomic Value of Odours.” Flink called flavor a “second way of smelling,” and much subsequent scientific investigation in the early 1900s focused on attempting to break down smell dimensions into basic categories, a feat that has proven too complicated due to the vast number and complexity of odors.
Food connoisseurs and chefs are increasingly capitalizing on the newly ascertained understanding of the role smell plays in flavor.
Food scientists Nicholas Kurti and Hervé This expanded upon the physiology of flavor and its importance in the culinary arts.
Today, one of the most active food psychologists, Paul Rozin has been the first to successfully map the role of retronasal smell in flavor.
[3] Sensory receptors in the mouth and nose are polarized at resting state, and they depolarize in response to some change in environment, such as coming in contact with odor molecules.
Odor molecules, consisting of hydrocarbon chains with functional groups, bind to sensory receptors in the nose and mouth.
This organization allows a vast amount of information to be concisely represented without requiring an equally large number of receptor types.
This dispersion of mitral cell information allows for self-excitatory feedback connections, lateral excitation, and self- and lateral-inhibition.
[5] Experience therefore strengthens signal-to-noise ratio in that a previously sensed odor object can be more easily distinguished against greater background noise.
[8] The orbitofrontal cortex (OFC) is the final destination of the odor information and is where conscious smell perception arises.
The OFC is responsible for selective odor tuning, fusing of sensory domains, and hedonic evaluations of smells.
This is because congestion blocks nasal passageways through which air and flavor molecules enter and exit, thus temporarily reducing retronasal smell capacity.
[9] As the exact processes are not yet fully understood and could be used for further development of food, retronasal perception is of particular importance for science and industry.
In practice, however, it is primarily the orthonasal perception that plays a role in the product, so that the comments of the very successful crowdfunding campaign were predominantly negative.
[11] Since 2017, the startup air up GmbH, a spin-off of the Technical University of Munich, has been working on a drinking bottle that aromatizes water via retronasal aroma perception.
Other speculations include the idea that the short route from the mouth to the nasal cavity resulted from selection from long-distance running when humans migrated out of Africa 2 million years ago.
Lieberman cites other evolutionary changes that could have resulted from selection for running such as wider joint cartilages and longer bones in the legs.
