AChemS Career Networking Seminar Series


"A Tale of Two Routes: Retro- vs Ortho-nasal Olfaction" by Robert Pellegrino, PhD and Kai Zhao, PhD
Odorant perception can be achieved through two routes: orthonasal and retronasal, with the latter being an important component of flavor perception and much less understood. Drs. Robert Pellegrino and Kai Zhao will each tell their unique tales about these different route based on their distinct research from unique, but different backgrounds. Dr. Pellegrino is trained as Food Scientist and clinical researcher, applying sensory science techniques to help diagnose and understand patients with olfactory loss; whereas Dr. Zhao, is trained as a bioengineering, or more specifically respiratory biofluid mechanics, where he has applied computational approaches to understand the physiological fluid and transport problems in the upper respiratory and especially nasal airway.

“Tale of Perception” by Robert Pellegrino, Ph.D
When you smell bread in a bakery or bite into a baguette, you are sampling the same odor via two routes (orthonsal and retronasal). If this odor is perceived differently across routes, then there are two distinct senses wrapped up in one leading to the idea of a duality in smell. None of the other five senses has this property. However looking at perceptual differences across routes has been a challenge in human studies, as the retronasal stimuli needs to be presented within the mouth without stimulating other senses (e.g. taste and touch). The goal of this research was to develop several tools to measure retronsasal perception in humans.

“Tale of Aerodynamics” by Kai Zhao, Ph.D.
Olfaction begins with the transport of volatile chemical molecules through the complicated nasal airway structure and subsequent absorption into the olfactory mucosa, prior to any olfactory perception. The difference of airflow transport patterns between the different routes might contribute to the difference between retro vs orthonasal olfaction and its differences among different species.